EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
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SECTION EC
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EC
Revision: October 2005 2005 QX56
INDEX FOR DTC ........................................................ 8
DTC No. Index ......................................................... 8
Alphabetical Index .................................................. 12
PRECAUTIONS ........................................................ 16
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ................................................................ 16
On Board Diagnostic (OBD) System of Engine and
A/T .......................................................................... 16
Precaution .............................................................. 16
Wiring Diagrams and Trouble Diagnosis ................ 19
PREPARATION ......................................................... 20
Special Service Tools ............................................. 20
Commercial Service Tools ...................................... 22
ENGINE CONTROL SYSTEM .................................. 23
System Diagram ..................................................... 23
Multiport Fuel Injection (MFI) System .................... 24
Electronic Ignition (EI) System ............................... 26
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................... 27
AIR CONDITIONING CUT CONTROL ..................... 28
Input/Output Signal Chart ....................................... 28
System Description ................................................ 28
AUTOMATIC SPEED CONTROL DEVICE (ASCD) ... 29
System Description ................................................ 29
Component Description .......................................... 30
CAN COMMUNICATION .......................................... 31
System Description ................................................ 31
EVAPORATIVE EMISSION SYSTEM ....................... 32
Description ............................................................. 32
Component Inspection ........................................... 35
Removal and Installation ........................................ 36
How to Detect Fuel Vapor Leakage ....................... 37
ON BOARD REFUELING VAPOR RECOVERY
(ORVR) ...................................................................... 39
System Description ................................................ 39
Diagnostic Procedure ............................................. 40
Component Inspection ........................................... 43
POSITIVE CRANKCASE VENTILATION ................. 45
Description .............................................................. 45
Component Inspection ............................................ 45
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-
NATS) ........................................................................ 47
Description .............................................................. 47
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 48
Introduction ............................................................. 48
Two Trip Detection Logic ........................................ 48
Emission-related Diagnostic Information ................ 49
Malfunction Indicator Lamp (MIL) ........................... 64
OBD System Operation Chart ................................ 66
BASIC SERVICE PROCEDURE ............................... 72
Basic Inspection ..................................................... 72
Idle Speed and Ignition Timing Check .................... 77
Idle Mixture Ratio Adjustment ................................. 79
VIN Registration ..................................................... 90
Accelerator Pedal Released Position Learning ...... 90
Throttle Valve Closed Position Learning ................. 90
Idle Air Volume Learning ........................................ 91
Fuel Pressure Check .............................................. 93
TROUBLE DIAGNOSIS ............................................ 95
Trouble Diagnosis Introduction ............................... 95
DTC Inspection Priority Chart ...............................101
Fail-safe Chart ......................................................103
Symptom Matrix Chart ..........................................104
Engine Control Component Parts Location ..........108
Vacuum Hose Drawing .........................................114
Circuit Diagram .....................................................115
ECM Harness Connector Terminal Layout ...........117
ECM Terminals and Reference Value ...................117
CONSULT-II Function (ENGINE) ..........................126
Generic Scan Tool (GST) Function .......................139
CONSULT-II Reference Value in Data Monitor .....141
Major Sensor Reference Graph in Data Monitor
Mode .....................................................................144
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .146
Description ............................................................146
Testing Condition ..................................................146
Inspection Procedure ............................................146
Diagnostic Procedure ...........................................147
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TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT .......................................................................156
Description ............................................................156
Diagnostic Procedure ...........................................156
POWER SUPPLY AND GROUND CIRCUIT ...........157
Wiring Diagram .....................................................157
Diagnostic Procedure ...........................................158
Ground Inspection ................................................162
DTC U1000, U1001 CAN COMMUNICATION LINE .163
Description ............................................................163
On Board Diagnosis Logic ....................................163
DTC Confirmation Procedure ...............................163
Wiring Diagram .....................................................164
Diagnostic Procedure ...........................................165
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER .166
Description ............................................................166
CONSULT-II Reference Value in Data Monitor Mode
.166
On Board Diagnosis Logic ....................................166
DTC Confirmation Procedure ...............................167
Wiring Diagram .....................................................168
Diagnostic Procedure ...........................................171
Component Inspection ..........................................173
Removal and Installation ......................................173
DTC P0101 MAF SENSOR .....................................174
Component Description ........................................174
CONSULT-II Reference Value in Data Monitor Mode
.174
On Board Diagnosis Logic ....................................174
DTC Confirmation Procedure ...............................175
Overall Function Check ........................................176
Wiring Diagram .....................................................177
Diagnostic Procedure ...........................................178
Component Inspection ..........................................181
Removal and Installation ......................................182
DTC P0102, P0103 MAF SENSOR .........................183
Component Description ........................................183
CONSULT-II Reference Value in Data Monitor Mode
.183
On Board Diagnosis Logic ....................................183
DTC Confirmation Procedure ...............................184
Wiring Diagram .....................................................185
Diagnostic Procedure ...........................................186
Component Inspection ..........................................189
Removal and Installation ......................................190
DTC P0112, P0113 IAT SENSOR ...........................191
Component Description ........................................191
On Board Diagnosis Logic ....................................191
DTC Confirmation Procedure ...............................191
Wiring Diagram .....................................................192
Diagnostic Procedure ...........................................193
Component Inspection ..........................................194
Removal and Installation ......................................194
DTC P0117, P0118 ECT SENSOR ..........................195
Component Description ........................................195
On Board Diagnosis Logic ....................................195
DTC Confirmation Procedure ...............................196
Wiring Diagram .....................................................197
Diagnostic Procedure ...........................................198
Component Inspection ..........................................199
Removal and Installation .......................................200
DTC P0122, P0123 TP SENSOR ............................201
Component Description ........................................201
CONSULT-II Reference Value in Data Monitor Mode
.201
On Board Diagnosis Logic ....................................201
DTC Confirmation Procedure ................................202
Wiring Diagram .....................................................203
Diagnostic Procedure ............................................204
Component Inspection ..........................................207
Removal and Installation .......................................207
DTC P0125 ECT SENSOR ......................................208
Component Description ........................................208
On Board Diagnosis Logic ....................................208
DTC Confirmation Procedure ................................209
Diagnostic Procedure ............................................209
Component Inspection ..........................................210
Removal and Installation .......................................210
DTC P0127 IAT SENSOR ........................................211
Component Description ........................................211
On Board Diagnosis Logic ....................................211
DTC Confirmation Procedure ................................211
Diagnostic Procedure ............................................212
Component Inspection ..........................................213
Removal and Installation .......................................213
DTC P0128 THERMOSTAT FUNCTION .................214
On Board Diagnosis Logic ....................................214
DTC Confirmation Procedure ................................214
Diagnostic Procedure ............................................214
Component Inspection ..........................................215
Removal and Installation .......................................215
DTC P0138, P0158 HO2S2 .....................................216
Component Description ........................................216
CONSULT-II Reference Value in Data Monitor Mode
.216
On Board Diagnosis Logic ....................................216
DTC Confirmation Procedure ................................217
Wiring Diagram .....................................................218
Diagnostic Procedure ............................................221
Component Inspection ..........................................223
Removal and Installation .......................................224
DTC P0139, P0159 HO2S2 .....................................225
Component Description ........................................225
CONSULT-II Reference Value in Data Monitor Mode
.225
On Board Diagnosis Logic ....................................225
DTC Confirmation Procedure ................................226
Overall Function Check .........................................226
Wiring Diagram .....................................................228
Diagnostic Procedure ............................................231
Component Inspection ..........................................234
Removal and Installation .......................................235
DTC P0171, P0174 FUEL INJECTION SYSTEM
FUNCTION ..............................................................236
On Board Diagnosis Logic ....................................236
DTC Confirmation Procedure ................................236
Wiring Diagram .....................................................238
Diagnostic Procedure ............................................240
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DTC P0172, P0175 FUEL INJECTION SYSTEM
FUNCTION .............................................................. 245
On Board Diagnosis Logic ................................... 245
DTC Confirmation Procedure ............................... 245
Wiring Diagram .................................................... 247
Diagnostic Procedure ........................................... 249
DTC P0181 FTT SENSOR ...................................... 253
Component Description ........................................ 253
On Board Diagnosis Logic ................................... 253
DTC Confirmation Procedure ............................... 253
Wiring Diagram .................................................... 255
Diagnostic Procedure ........................................... 256
Component Inspection ......................................... 258
Removal and Installation ...................................... 258
DTC P0182, P0183 FTT SENSOR ......................... 259
Component Description ........................................ 259
On Board Diagnosis Logic ................................... 259
DTC Confirmation Procedure ............................... 259
Wiring Diagram .................................................... 260
Diagnostic Procedure ........................................... 261
Component Inspection ......................................... 263
Removal and Installation ...................................... 263
DTC P0222, P0223 TP SENSOR ........................... 264
Component Description ........................................ 264
CONSULT-II Reference Value in Data Monitor Mode
. 264
On Board Diagnosis Logic ................................... 264
DTC Confirmation Procedure ............................... 265
Wiring Diagram .................................................... 266
Diagnostic Procedure ........................................... 267
Component Inspection ......................................... 270
Removal and Installation ...................................... 270
DTC P0300 - P0308 MULTIPLE CYLINDER MIS-
FIRE, NO. 1 - 8 CYLINDER MISFIRE ..................... 271
On Board Diagnosis Logic ................................... 271
DTC Confirmation Procedure ............................... 271
Diagnostic Procedure ........................................... 272
DTC P0327, P0328, P0332, P0333 KS .................. 279
Component Description ........................................ 279
On Board Diagnosis Logic ................................... 279
DTC Confirmation Procedure ............................... 279
Wiring Diagram .................................................... 280
Diagnostic Procedure ........................................... 281
Component Inspection ......................................... 283
Removal and Installation ...................................... 283
DTC P0335 CKP SENSOR (POS) .......................... 284
Component Description ........................................ 284
CONSULT-II Reference Value in Data Monitor Mode
. 284
On Board Diagnosis Logic ................................... 284
DTC Confirmation Procedure ............................... 284
Wiring Diagram .................................................... 286
Diagnostic Procedure ........................................... 287
Component Inspection ......................................... 290
Removal and Installation ...................................... 290
DTC P0340 CMP SENSOR (PHASE) ..................... 291
Component Description ........................................ 291
On Board Diagnosis Logic ................................... 291
DTC Confirmation Procedure ............................... 291
Wiring Diagram .....................................................293
Diagnostic Procedure ...........................................294
Component Inspection ..........................................297
Removal and Installation ......................................297
DTC P0420, P0430 THREE WAY CATALYST FUNC-
TION ........................................................................298
On Board Diagnosis Logic ....................................298
DTC Confirmation Procedure ...............................298
Overall Function Check ........................................299
Diagnostic Procedure ...........................................300
DTC P0441 EVAP CONTROL SYSTEM .................304
System Description ...............................................304
On Board Diagnosis Logic ....................................304
DTC Confirmation Procedure ...............................304
Overall Function Check ........................................305
Diagnostic Procedure ...........................................306
DTC P0442 EVAP CONTROL SYSTEM .................309
On Board Diagnosis Logic ....................................309
DTC Confirmation Procedure ...............................310
Diagnostic Procedure ...........................................311
DTC P0444, P0445 EVAP CANISTER PURGE VOL-
UME CONTROL SOLENOID VALVE ......................318
Description ............................................................318
CONSULT-II Reference Value in Data Monitor Mode
.318
On Board Diagnosis Logic ....................................319
DTC Confirmation Procedure ...............................319
Wiring Diagram .....................................................320
Diagnostic Procedure ...........................................322
Component Inspection ..........................................323
Removal and Installation ......................................324
DTC P0447 EVAP CANISTER VENT CONTROL
VALVE .....................................................................325
Component Description ........................................325
CONSULT-II Reference Value in Data Monitor Mode
.325
On Board Diagnosis Logic ....................................325
DTC Confirmation Procedure ...............................326
Wiring Diagram .....................................................327
Diagnostic Procedure ...........................................328
Component Inspection ..........................................330
DTC P0451 EVAP CONTROL SYSTEM PRESSURE
SENSOR .................................................................332
Component Description ........................................332
CONSULT-II Reference Value in Data Monitor Mode
.332
On Board Diagnosis Logic ....................................332
DTC Confirmation Procedure ...............................333
Diagnostic Procedure ...........................................333
Component Inspection ..........................................334
DTC P0452 EVAP CONTROL SYSTEM PRESSURE
SENSOR .................................................................335
Component Description ........................................335
CONSULT-II Reference Value in Data Monitor Mode
.335
On Board Diagnosis Logic ....................................335
DTC Confirmation Procedure ...............................336
Wiring Diagram .....................................................337
EC-4
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Diagnostic Procedure ...........................................338
Component Inspection ..........................................340
DTC P0453 EVAP CONTROL SYSTEM PRESSURE
SENSOR ..................................................................341
Component Description ........................................341
CONSULT-II Reference Value in Data Monitor Mode
.341
On Board Diagnosis Logic ....................................341
DTC Confirmation Procedure ...............................342
Wiring Diagram .....................................................343
Diagnostic Procedure ...........................................344
Component Inspection ..........................................348
DTC P0455 EVAP CONTROL SYSTEM .................349
On Board Diagnosis Logic ....................................349
DTC Confirmation Procedure ...............................350
Diagnostic Procedure ...........................................351
DTC P0456 EVAP CONTROL SYSTEM .................357
On Board Diagnosis Logic ....................................357
DTC Confirmation Procedure ...............................358
Overall Function Check ........................................359
Diagnostic Procedure ...........................................360
DTC P0460 FUEL LEVEL SENSOR .......................366
Component Description ........................................366
On Board Diagnosis Logic ....................................366
DTC Confirmation Procedure ...............................366
Diagnostic Procedure ...........................................367
Removal and Installation ......................................367
DTC P0461 FUEL LEVEL SENSOR .......................368
Component Description ........................................368
On Board Diagnosis Logic ....................................368
Overall Function Check ........................................368
Diagnostic Procedure ...........................................369
Removal and Installation ......................................369
DTC P0462, P0463 FUEL LEVEL SENSOR CIR-
CUIT ........................................................................370
Component Description ........................................370
On Board Diagnosis Logic ....................................370
DTC Confirmation Procedure ...............................370
Diagnostic Procedure ...........................................371
Removal and Installation ......................................371
DTC P0500 VSS ......................................................372
Description ............................................................372
On Board Diagnosis Logic ....................................372
DTC Confirmation Procedure ...............................372
Overall Function Check ........................................372
Diagnostic Procedure ...........................................373
DTC P0506 ISC SYSTEM .......................................374
Description ............................................................374
On Board Diagnosis Logic ....................................374
DTC Confirmation Procedure ...............................374
Diagnostic Procedure ...........................................375
DTC P0507 ISC SYSTEM .......................................376
Description ............................................................376
On Board Diagnosis Logic ....................................376
DTC Confirmation Procedure ...............................376
Diagnostic Procedure ...........................................377
DTC P0550 PSP SENSOR ......................................378
Component Description ........................................378
CONSULT-II Reference Value in Data Monitor Mode
.378
On Board Diagnosis Logic ....................................378
DTC Confirmation Procedure ................................378
Wiring Diagram .....................................................379
Diagnostic Procedure ............................................380
Component Inspection ..........................................382
Removal and Installation .......................................382
DTC P0605 ECM .....................................................383
Component Description ........................................383
On Board Diagnosis Logic ....................................383
DTC Confirmation Procedure ................................383
Diagnostic Procedure ............................................384
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1
HEATER ...................................................................386
Description ............................................................386
CONSULT-II Reference Value in Data Monitor Mode
.386
On Board Diagnosis Logic ....................................386
DTC Confirmation Procedure ................................386
Wiring Diagram .....................................................387
Diagnostic Procedure ............................................390
Component Inspection ..........................................392
Removal and Installation .......................................392
DTC P1065 ECM POWER SUPPLY ........................393
Component Description ........................................393
On Board Diagnosis Logic ....................................393
DTC Confirmation Procedure ................................393
Wiring Diagram .....................................................394
Diagnostic Procedure ............................................395
DTC P1121 ELECTRIC THROTTLE CONTROL
ACTUATOR .............................................................397
Component Description ........................................397
On Board Diagnosis Logic ....................................397
DTC Confirmation Procedure ................................397
Diagnostic Procedure ............................................398
DTC P1122 ELECTRIC THROTTLE CONTROL
FUNCTION ..............................................................399
Description ............................................................399
On Board Diagnosis Logic ....................................399
DTC Confirmation Procedure ................................399
Wiring Diagram .....................................................400
Diagnostic Procedure ............................................401
Component Inspection ..........................................404
Removal and Installation .......................................404
DTC P1124, P1126 THROTTLE CONTROL MOTOR
RELAY .....................................................................405
Component Description ........................................405
CONSULT-II Reference Value in Data Monitor Mode
.405
On Board Diagnosis Logic ....................................405
DTC Confirmation Procedure ................................405
Wiring Diagram .....................................................407
Diagnostic Procedure ............................................408
DTC P1128 THROTTLE CONTROL MOTOR .........410
Component Description ........................................410
On Board Diagnosis Logic ....................................410
DTC Confirmation Procedure ................................410
Wiring Diagram .....................................................411
Diagnostic Procedure ............................................412
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Component Inspection ......................................... 413
Removal and Installation ...................................... 414
DTC P1146, P1166 HO2S2 ..................................... 415
Component Description ........................................ 415
CONSULT-II Reference Value in Data Monitor Mode
. 415
On Board Diagnosis Logic ................................... 415
DTC Confirmation Procedure ............................... 416
Overall Function Check ........................................ 416
Wiring Diagram .................................................... 418
Diagnostic Procedure ........................................... 421
Component Inspection ......................................... 424
Removal and Installation ...................................... 425
DTC P1147, P1167 HO2S2 ..................................... 426
Component Description ........................................ 426
CONSULT-II Reference Value in Data Monitor Mode
. 426
On Board Diagnosis Logic ................................... 426
DTC Confirmation Procedure ............................... 427
Overall Function Check ........................................ 427
Wiring Diagram .................................................... 429
Diagnostic Procedure ........................................... 432
Component Inspection ......................................... 435
Removal and Installation ...................................... 436
DTC P1148, P1168 CLOSED LOOP CONTROL .... 437
On Board Diagnosis Logic ................................... 437
DTC P1211 TCS CONTROL UNIT ......................... 438
Description ........................................................... 438
On Board Diagnosis Logic ................................... 438
DTC Confirmation Procedure ............................... 438
Diagnostic Procedure ........................................... 438
DTC P1212 TCS COMMUNICATION LINE ............ 439
Description ........................................................... 439
On Board Diagnosis Logic ................................... 439
DTC Confirmation Procedure ............................... 439
Diagnostic Procedure ........................................... 439
DTC P1217 ENGINE OVER TEMPERATURE ....... 440
Description ........................................................... 440
CONSULT-II Reference Value in Data Monitor Mode
. 440
On Board Diagnosis Logic ................................... 441
Overall Function Check ........................................ 441
Wiring Diagram .................................................... 443
Diagnostic Procedure ........................................... 445
Main 12 Causes of Overheating ........................... 448
Component Inspection ......................................... 449
DTC P1225 TP SENSOR ........................................ 450
Component Description ........................................ 450
On Board Diagnosis Logic ................................... 450
DTC Confirmation Procedure ............................... 450
Diagnostic Procedure ........................................... 451
Removal and Installation ...................................... 451
DTC P1226 TP SENSOR ........................................ 452
Component Description ........................................ 452
On Board Diagnosis Logic ................................... 452
DTC Confirmation Procedure ............................... 452
Diagnostic Procedure ........................................... 453
Removal and Installation ...................................... 453
DTC P1229 SENSOR POWER SUPPLY ................ 454
On Board Diagnosis Logic ....................................454
DTC Confirmation Procedure ...............................454
Wiring Diagram .....................................................455
Diagnostic Procedure ...........................................456
DTC P1271, P1281 A/F SENSOR 1 .......................459
Component Description ........................................459
CONSULT-II Reference Value in Data Monitor Mode
.459
On Board Diagnosis Logic ....................................459
DTC Confirmation Procedure ...............................459
Wiring Diagram .....................................................461
Diagnostic Procedure ...........................................464
Removal and Installation ......................................467
DTC P1272, P1282 A/F SENSOR 1 .......................468
Component Description ........................................468
CONSULT-II Reference Value in Data Monitor Mode
.468
On Board Diagnosis Logic ....................................468
DTC Confirmation Procedure ...............................468
Wiring Diagram .....................................................470
Diagnostic Procedure ...........................................473
Removal and Installation ......................................476
DTC P1273, P1283 A/F SENSOR 1 .......................477
Component Description ........................................477
CONSULT-II Reference Value in Data Monitor Mode
.477
On Board Diagnosis Logic ....................................477
DTC Confirmation Procedure ...............................477
Wiring Diagram .....................................................479
Diagnostic Procedure ...........................................482
Removal and Installation ......................................486
DTC P1274, P1284 A/F SENSOR 1 .......................487
Component Description ........................................487
CONSULT-II Reference Value in Data Monitor Mode
.487
On Board Diagnosis Logic ....................................487
DTC Confirmation Procedure ...............................487
Wiring Diagram .....................................................489
Diagnostic Procedure ...........................................492
Removal and Installation ......................................496
DTC P1276, P1286 A/F SENSOR 1 .......................497
Component Description ........................................497
CONSULT-II Reference Value in Data Monitor Mode
.497
On Board Diagnosis Logic ....................................497
DTC Confirmation Procedure ...............................497
Overall Function Check ........................................498
Wiring Diagram .....................................................500
Diagnostic Procedure ...........................................503
Removal and Installation ......................................506
DTC P1278, P1288 A/F SENSOR 1 .......................507
Component Description ........................................507
CONSULT-II Reference Value in Data Monitor Mode
.507
On Board Diagnosis Logic ....................................507
DTC Confirmation Procedure ...............................508
Wiring Diagram .....................................................510
Diagnostic Procedure ...........................................513
Removal and Installation ......................................518
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DTC P1279, P1289 A/F SENSOR 1 ........................519
Component Description ........................................519
CONSULT-II Reference Value in Data Monitor Mode
.519
On Board Diagnosis Logic ....................................519
DTC Confirmation Procedure ...............................520
Wiring Diagram .....................................................522
Diagnostic Procedure ...........................................525
Removal and Installation ......................................530
DTC P1444 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE ...............................531
Description ............................................................531
CONSULT-II Reference Value in Data Monitor Mode
.531
On Board Diagnosis Logic ....................................532
DTC Confirmation Procedure ...............................532
Wiring Diagram .....................................................533
Diagnostic Procedure ...........................................535
Component Inspection ..........................................538
Removal and Installation ......................................538
DTC P1446 EVAP CANISTER VENT CONTROL
VALVE .....................................................................539
Component Description ........................................539
CONSULT-II Reference Value in Data Monitor Mode
.539
On Board Diagnosis Logic ....................................539
DTC Confirmation Procedure ...............................540
Wiring Diagram .....................................................541
Diagnostic Procedure ...........................................542
Component Inspection ..........................................543
DTC P1564 ICC STEERING SWITCH ....................545
Component Description ........................................545
CONSULT-II Reference Value in Data Monitor Mode
.545
On Board Diagnosis Logic ....................................545
DTC Confirmation Procedure ...............................546
Wiring Diagram .....................................................547
Diagnostic Procedure ...........................................548
Component Inspection ..........................................551
DTC P1564 ASCD STEERING SWITCH ................552
Component Description ........................................552
CONSULT-II Reference Value in Data Monitor Mode
.552
On Board Diagnosis Logic ....................................552
DTC Confirmation Procedure ...............................553
Wiring Diagram .....................................................554
Diagnostic Procedure ...........................................555
Component Inspection ..........................................558
DTC P1568 ICC FUNCTION ...................................559
On Board Diagnosis Logic ....................................559
DTC Confirmation Procedure ...............................559
Diagnostic Procedure ...........................................559
DTC P1572 ICC BRAKE SWITCH ..........................560
Component Description ........................................560
CONSULT-II Reference Value in Data Monitor Mode
.560
On Board Diagnosis Logic ....................................560
DTC Confirmation Procedure ...............................561
Wiring Diagram .....................................................562
Diagnostic Procedure ............................................563
Component Inspection ..........................................567
DTC P1572 ASCD BRAKE SWITCH ......................569
Component Description ........................................569
CONSULT-II Reference Value in Data Monitor Mode
.569
On Board Diagnosis Logic ....................................569
DTC confirmation Procedure ................................570
Wiring Diagram .....................................................571
Diagnostic Procedure ............................................572
Component Inspection ..........................................576
DTC P1574 ICC VEHICLE SPEED SENSOR .........577
Component Description ........................................577
On Board Diagnosis Logic ....................................577
DTC Confirmation Procedure ................................577
Diagnostic Procedure ............................................578
DTC P1574 ASCD VEHICLE SPEED SENSOR .....579
Component Description ........................................579
On Board Diagnosis Logic ....................................579
DTC Confirmation Procedure ................................579
Diagnostic Procedure ............................................580
DTC P1706 PNP SWITCH .......................................581
Component Description ........................................581
CONSULT-II Reference Value in Data Monitor Mode
.581
On Board Diagnosis Logic ....................................581
DTC Confirmation Procedure ................................581
Overall Function Check .........................................582
Wiring Diagram .....................................................583
Diagnostic Procedure ............................................584
DTC P1805 BRAKE SWITCH .................................586
Description ............................................................586
CONSULT-II Reference Value in Data Monitor Mode
.586
On Board Diagnosis Logic ....................................586
DTC Confirmation Procedure ................................586
Wiring Diagram .....................................................587
Diagnostic Procedure ............................................588
Component Inspection ..........................................590
DTC P2122, P2123 APP SENSOR .........................591
Component Description ........................................591
CONSULT-II Reference Value in Data Monitor Mode
.591
On Board Diagnosis Logic ....................................591
DTC Confirmation Procedure ................................592
Wiring Diagram .....................................................593
Diagnostic Procedure ............................................594
Component Inspection ..........................................596
Removal and Installation .......................................596
DTC P2127, P2128 APP SENSOR .........................597
Component Description ........................................597
CONSULT-II Reference Value in Data Monitor Mode
.597
On Board Diagnosis Logic ....................................597
DTC Confirmation Procedure ................................598
Wiring Diagram .....................................................599
Diagnostic Procedure ............................................600
Component Inspection ..........................................603
Removal and Installation .......................................603
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DTC P2135 TP SENSOR ........................................ 604
Component Description ........................................ 604
CONSULT-II Reference Value in Data Monitor Mode
. 604
On Board Diagnosis Logic ................................... 604
DTC Confirmation Procedure ............................... 605
Wiring Diagram .................................................... 606
Diagnostic Procedure ........................................... 607
Component Inspection ......................................... 610
Removal and Installation ...................................... 610
DTC P2138 APP SENSOR ......................................611
Component Description .........................................611
CONSULT-II Reference Value in Data Monitor Mode
..611
On Board Diagnosis Logic ....................................611
DTC Confirmation Procedure ............................... 612
Wiring Diagram .................................................... 613
Diagnostic Procedure ........................................... 614
Component Inspection ......................................... 618
Removal and Installation ...................................... 618
IGNITION SIGNAL .................................................. 619
Component Description ........................................ 619
Wiring Diagram .................................................... 620
Diagnostic Procedure ........................................... 625
Component Inspection ......................................... 629
Removal and Installation ...................................... 630
INJECTOR CIRCUIT ............................................... 631
Component Description ........................................ 631
CONSULT-II Reference Value in Data Monitor Mode
. 631
Wiring Diagram .................................................... 632
Diagnostic Procedure ........................................... 633
Component Inspection ......................................... 636
Removal and Installation ...................................... 636
FUEL PUMP CIRCUIT ............................................ 637
Description ........................................................... 637
CONSULT-II Reference Value in Data Monitor Mode
. 637
Wiring Diagram .................................................... 638
Diagnostic Procedure ........................................... 639
Component Inspection ......................................... 642
Removal and Installation ...................................... 642
REFRIGERANT PRESSURE SENSOR ................. 643
Component Description ........................................ 643
Wiring Diagram .....................................................644
Diagnostic Procedure ...........................................645
Removal and Installation ......................................647
ELECTRICAL LOAD SIGNAL ................................648
Description ............................................................648
CONSULT-II Reference Value in Data Monitor Mode
.648
Diagnostic Procedure ...........................................648
ICC BRAKE SWITCH .............................................649
Component Description ........................................649
CONSULT-II Reference Value in Data Monitor Mode
.649
Wiring Diagram .....................................................650
Diagnostic Procedure ...........................................651
Component Inspection ..........................................656
ASCD BRAKE SWITCH .........................................657
Component Description ........................................657
CONSULT-II Reference Value in Data Monitor Mode
.657
Wiring Diagram .....................................................658
Diagnostic Procedure ...........................................659
Component Inspection ..........................................663
ASCD INDICATOR ..................................................664
Component Description ........................................664
CONSULT-II Reference Value in Data Monitor Mode
.664
Wiring Diagram .....................................................665
Diagnostic Procedure ...........................................666
MIL AND DATA LINK CONNECTOR ......................667
Wiring Diagram .....................................................667
SERVICE DATA AND SPECIFICATIONS (SDS) ....669
Fuel Pressure .......................................................669
Idle Speed and Ignition Timing .............................669
Calculated Load Value ..........................................669
Mass Air Flow Sensor ...........................................669
Intake Air Temperature Sensor .............................669
Engine Coolant Temperature Sensor ...................669
A/F Sensor 1 Heater .............................................669
Heated Oxygen sensor 2 Heater ..........................669
Crankshaft Position Sensor (POS) .......................669
Camshaft Position Sensor (PHASE) ....................669
Throttle Control Motor ...........................................669
Injector ..................................................................670
Fuel Pump ............................................................670
EC-8
Revision: October 2005
INDEX FOR DTC
2005 QX56
INDEX FOR DTC PFP:00024
DTC No. Index UBS00KYY
NOTE:
If DTC U1000 or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
DTC*
1
Items
(CONSULT-II screen terms)
Reference page
CONSULT-II
GST*
2
ECM*
3
U1000
1000*
4
CAN COMM CIRCUIT EC-163
U1001
1001*
4
CAN COMM CIRCUIT EC-163
P0000 0000
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.
—
P0037 0037 HO2S2 HTR (B1) EC-166
P0038 0038 HO2S2 HTR (B1) EC-166
P0057 0057 HO2S2 HTR (B2) EC-166
P0058 0058 HO2S2 HTR (B2) EC-166
P0101 0101 MAF SEN/CIRCUIT EC-174
P0102 0102 MAF SEN/CIRCUIT EC-183
P0103 0103 MAF SEN/CIRCUIT EC-183
P0112 0112 IAT SEN/CIRCUIT EC-191
P0113 0113 IAT SEN/CIRCUIT EC-191
P0117 0117 ECT SEN/CIRCUIT EC-195
P0118 0118 ECT SEN/CIRCUIT EC-195
P0122 0122 TP SEN 2/CIRC EC-201
P0123 0123 TP SEN 2/CIRC EC-201
P0125 0125 ECT SENSOR EC-208
P0127 0127 IAT SENSOR EC-211
P0128 0128 THERMSTAT FNCTN EC-214
P0138 0138 HO2S2 (B1) EC-216
P0139 0139 HO2S2 (B1) EC-225
P0158 0158 HO2S2 (B2) EC-216
P0159 0159 HO2S2 (B2) EC-225
P0171 0171 FUEL SYS-LEAN-B1 EC-236
P0172 0172 FUEL SYS-RICH-B1 EC-245
P0174 0174 FUEL SYS-LEAN-B2 EC-236
P0175 0175 FUEL SYS-RICH-B2 EC-245
P0181 0181 FTT SENSOR EC-253
P0182 0182 FTT SEN/CIRCUIT EC-259
P0183 0183 FTT SEN/CIRCUIT EC-259
P0222 0222 TP SEN 1/CIRC EC-264
P0223 0223 TP SEN 1/CIRC EC-264
P0300 0300 MULTI CYL MISFIRE EC-271
P0301 0301 CYL 1 MISFIRE EC-271
P0302 0302 CYL 2 MISFIRE EC-271
P0303 0303 CYL 3 MISFIRE EC-271
INDEX FOR DTC
EC-9
C
D
E
F
G
H
I
J
K
L
M
A
EC
Revision: October 2005 2005 QX56
P0304 0304 CYL 4 MISFIRE EC-271
P0305 0305 CYL 5 MISFIRE EC-271
P0306 0306 CYL 6 MISFIRE EC-271
P0307 0307 CYL 7 MISFIRE EC-271
P0308 0308 CYL 8 MISFIRE EC-271
P0327 0327 KNOCK SEN/CIRC-B1 EC-279
P0328 0328 KNOCK SEN/CIRC-B1 EC-279
P0332 0332 KNOCK SEN/CIRC-B2 EC-279
P0333 0333 KNOCK SEN/CIRC-B2 EC-279
P0335 0335 CKP SEN/CIRCUIT EC-284
P0340 0340 CMP SEN/CIRC-B1 EC-291
P0420 0420 TW CATALYST SYS-B1 EC-298
P0430 0430 TW CATALYST SYS-B2 EC-298
P0441 0441 EVAP PURG FLOW/MON EC-304
P0442 0442 EVAP SMALL LEAK EC-309
P0444 0444 PURG VOLUME CONT/V EC-318
P0445 0445 PURG VOLUME CONT/V EC-318
P0447 0447 VENT CONTROL VALVE EC-325
P0451 0451 EVAP SYS PRES SEN EC-332
P0452 0452 EVAP SYS PRES SEN EC-335
P0453 0453 EVAP SYS PRES SEN EC-341
P0455 0455 EVAP GROSS LEAK EC-349
P0456 0456 EVAP VERY SML LEAK EC-357
P0460 0460 FUEL LEV SEN SLOSH EC-366
P0461 0461 FUEL LEVEL SENSOR EC-368
P0462 0462 FUEL LEVL SEN/CIRC EC-370
P0463 0463 FUEL LEVL SEN/CIRC EC-370
P0500 0500
VEH SPEED SEN/CIRC*
5
EC-372
P0506 0506 ISC SYSTEM EC-374
P0507 0507 ISC SYSTEM EC-376
P0550 0550 PW ST P SEN/CIRC EC-378
P0605 0605 ECM EC-383
P0700 0700 TCM AT-103
P0705 0705 PNP SW/CIRC AT-104
P0710 0710 ATF TEMP SEN/CIRC AT-126
P0720 0720
VEH SPD SEN/CIR AT*
5
AT-108
P0740 0740 TCC SOLENOID/CIRC AT-115
P0744 0744 A/T TCC S/V FNCTN AT-117
P0745 0745 L/PRESS SOL/CIRC AT-119
P1031 1031 A/F SEN1 HTR (B1) EC-386
P1032 1032 A/F SEN1 HTR (B1) EC-386
P1051 1051 A/F SEN1 HTR (B2) EC-386
DTC*
1
Items
(CONSULT-II screen terms)
Reference page
CONSULT-II
GST*
2
ECM*
3
EC-10
Revision: October 2005
INDEX FOR DTC
2005 QX56
P1052 1052 A/F SEN1 HTR (B2) EC-386
P1065 1065 ECM BACK UP/CIRCUIT EC-393
P1121 1121 ETC ACTR EC-397
P1122 1122 ETC FUNCTION/CIRC EC-399
P1124 1124 ETC MOT PWR EC-405
P1126 1126 ETC MOT PWR EC-405
P1128 1128 ETC MOT EC-410
P1146 1146 HO2S2 (B2) EC-415
P1147 1147 HO2S2 (B2) EC-426
P1148 1148 CLOSED LOOP-B1 EC-437
P1166 1166 HO2S2 (B2) EC-415
P1167 1167 HO2S2 (B2) EC-426
P1168 1168 CLOSED LOOP-B2 EC-437
P1211 1211 TCS C/U FUNCTN EC-438
P1212 1212 TCS/CIRC EC-439
P1217 1217 ENG OVER TEMP EC-440
P1225 1225 CTP LEARNING EC-450
P1226 1226 CTP LEARNING EC-452
P1229 1229 SENSOR POWER/CIRC EC-454
P1271 1271 A/F SEN1 (B1) EC-459
P1272 1272 A/F SENSOR1 (B1) EC-468
P1273 1273 A/F SENSOR1 (B1) EC-477
P1274 1274 A/F SENSOR1 (B1) EC-487
P1276 1276 A/F SENSOR1 (B1) EC-497
P1278 1278 A/F SENSOR1 (B1) EC-507
P1279 1279 A/F SENSOR1 (B1) EC-519
P1281 1281 A/F SENSOR1 (B2) EC-459
P1282 1282 A/F SENSOR1 (B2) EC-468
P1283 1283 A/F SENSOR1 (B2) EC-477
P1284 1284 A/F SENSOR1 (B2) EC-487
P1286 1286 A/F SENSOR1 (B2) EC-497
P1288 1288 A/F SENSOR1 (B2) EC-507
P1289 1289 A/F SENSOR1 (B2) EC-519
P1444 1444 PURG VOLUME CONT/V EC-531
P1446 1446 VENT CONTROL VALVE EC-539
P1564 1564 ASCD SW
EC-545
(Models with ICC)
EC-552
(Models with ASCD)
P1568 1568
ACC COMMAND VALUE*
7
EC-559
P1572 1572 ASCD BRAKE SW
EC-560 (Models with ICC)
EC-569
(Models with ASCD)
P1574 1574
ASCD VHL SPD SEN*
6
EC-577 (Models with ICC)
EC-579
(Models with ASCD)
P1610 - P1615 1610 - 1615 NATS MALFUNCTION BL-137
DTC*
1
Items
(CONSULT-II screen terms)
Reference page
CONSULT-II
GST*
2
ECM*
3
INDEX FOR DTC
EC-11
C
D
E
F
G
H
I
J
K
L
M
A
EC
Revision: October 2005 2005 QX56
*1: 1st trip DTC No. is the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results), this number is controlled by NISSAN.
*4: The troubleshooting for this DTC needs CONSULT-II.
*5: When the fail-safe operations for both self-diagnoses occur, the MIL illuminates.
*6: 2WD models
*7: Models with ICC
P1706 1706 P-N POS SW/CIRCUIT EC-581
P1716 1716 TURBINE REV S/CIRC AT-131
P1730 1730 A/T INTERLOCK AT-135
P1752 1752 I/C SOLENOID/CIRC AT-140
P1754 1754 I/C SOLENOID FNCTN AT-142
P1757 1757 FR/B SOLENOID/CIRC AT-144
P1759 1759 FR/B SOLENOID FNCT AT-146
P1762 1762 D/C SOLENOID/CIRC AT-148
P1764 1764 D/C SOLENOID FNCTN AT-150
P1767 1767 HLR/C SOL/CIRC AT-152
P1769 1769 HLR/C SOL FNCTN AT-154
P1772 1772 LC/B SOLENOID/CIRC AT-156
P1774 1774 LC/B SOLENOID FNCT AT-158
P1805 1805 BRAKE SW/CIRCUIT EC-586
P2122 2122 APP SEN 1/CIRC EC-591
P2123 2123 APP SEN 1/CIRC EC-591
P2127 2127 APP SEN 2/CIRC EC-597
P2128 2128 APP SEN 2/CIRC EC-597
P2135 2135 TP SENSOR EC-604
P2138 2138 APP SENSOR EC-611
DTC*
1
Items
(CONSULT-II screen terms)
Reference page
CONSULT-II
GST*
2
ECM*
3
EC-12
Revision: October 2005
INDEX FOR DTC
2005 QX56
Alphabetical Index UBS00KYZ
NOTE:
If DTC U1000 or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Items
(CONSULT-II screen terms)
DTC*
1
Reference page
CONSULT-II
GST*
2
ECM*
3
A/F SENSOR1 (B1) P1271 1271 EC-459
A/F SENSOR1 (B1) P1272 1272 EC-468
A/F SENSOR1 (B1) P1273 1273 EC-477
A/F SENSOR1 (B1) P1274 1274 EC-487
A/F SENSOR1 (B1) P1276 1276 EC-497
A/F SENSOR1 (B1) P1278 1278 EC-507
A/F SENSOR1 (B1) P1279 1279 EC-519
A/F SENSOR1 (B2) P1281 1281 EC-459
A/F SENSOR1 (B2) P1282 1282 EC-468
A/F SENSOR1 (B2) P1283 1283 EC-477
A/F SENSOR1 (B2) P1284 1284 EC-487
A/F SENSOR1 (B2) P1286 1286 EC-497
A/F SENSOR1 (B2) P1288 1288 EC-507
A/F SENSOR1 (B2) P1289 1289 EC-519
A/F SEN1 HTR (B1) P1031 1031 EC-386
A/F SEN1 HTR (B1) P1032 1032 EC-386
A/F SEN1 HTR (B2) P1051 1051 EC-386
A/F SEN1 HTR (B2) P1052 1052 EC-386
A/T INTERLOCK P1730 1730 AT-135
A/T TCC S/V FNCTN P0744 0744 AT-117
ACC COMMAND VALUE*
7
P1568 1568 EC-559
APP SEN 1/CIRC P2122 2122 EC-591
APP SEN 1/CIRC P2123 2123 EC-591
APP SEN 2/CIRC P2127 2127 EC-597
APP SEN 2/CIRC P2128 2128 EC-597
APP SENSOR P2138 2138 EC-611
ASCD BRAKE SW P1572 1572
EC-560
(Models with ICC)
EC-569
(Models with ASCD)
ASCD SW P1564 1564
EC-545
(Models with ICC)
EC-552
(Models with ASCD)
ASCD VHL SPD SEN*
6
P1574 1574
EC-577
(Models with ICC)
EC-579
(Models with ASCD)
ATF TEMP SEN/CIRC P0710 0710 AT-126
BRAKE SW/CIRCUIT P1805 1805 EC-586
CAN COMM CIRCUIT U1000
1000*
4
EC-163
CAN COMM CIRCUIT U1001
1001*
4
EC-163
CKP SEN/CIRCUIT P0335 0335 EC-284
CLOSED LOOP-B1 P1148 1148 EC-437
CLOSED LOOP-B2 P1168 1168 EC-437
INDEX FOR DTC
EC-13
C
D
E
F
G
H
I
J
K
L
M
A
EC
Revision: October 2005 2005 QX56
CMP SEN/CIRC-B1 P0340 0340 EC-291
CTP LEARNING P1225 1225 EC-450
CTP LEARNING P1226 1226 EC-452
CYL 1 MISFIRE P0301 0301 EC-271
CYL 2 MISFIRE P0302 0302 EC-271
CYL 3 MISFIRE P0303 0303 EC-271
CYL 4 MISFIRE P0304 0304 EC-271
CYL 5 MISFIRE P0305 0305 EC-271
CYL 6 MISFIRE P0306 0306 EC-271
CYL 7 MISFIRE P0307 0307 EC-271
CYL 8 MISFIRE P0308 0308 EC-271
D/C SOLENOID/CIRC P1762 1762 AT-148
D/C SOLENOID FNCTN P1764 1764 AT-150
ECM P0605 0605 EC-383
ECM BACK UP/CIRCUIT P1065 1065 EC-393
ECT SEN/CIRCUIT P0117 0117 EC-195
ECT SEN/CIRCUIT P0118 0118 EC-195
ECT SENSOR P0125 0125 EC-208
ENG OVER TEMP P1217 1217 EC-440
ETC ACTR P1121 1121 EC-397
ETC FUNCTION/CIRC P1122 1122 EC-399
ETC MOT P1128 1128 EC-410
ETC MOT PWR P1124 1124 EC-405
ETC MOT PWR P1126 1126 EC-405
EVAP GROSS LEAK P0455 0455 EC-349
EVAP PURG FLOW/MON P0441 0441 EC-304
EVAP SMALL LEAK P0442 0442 EC-309
EVAP SYS PRES SEN P0451 0451 EC-332
EVAP SYS PRES SEN P0452 0452 EC-335
EVAP SYS PRES SEN P0453 0453 EC-341
EVAP VERY SML LEAK P0456 0456 EC-357
FR/B SOLENOID/CIRC P1757 1757 AT-144
FR/B SOLENOID FNCT P1759 1759 AT-146
FTT SEN/CIRCUIT P0182 0182 EC-259
FTT SEN/CIRCUIT P0183 0183 EC-259
FTT SENSOR P0181 0181 EC-253
FUEL LEV SEN SLOSH P0460 0460 EC-366
FUEL LEVEL SENSOR P0461 0461 EC-368
FUEL LEVL SEN/CIRC P0462 0462 EC-370
FUEL LEVL SEN/CIRC P0463 0463 EC-370
FUEL SYS-LEAN-B1 P0171 0171 EC-236
FUEL SYS-LEAN-B2 P0174 0174 EC-236
Items
(CONSULT-II screen terms)
DTC*
1
Reference page
CONSULT-II
GST*
2
ECM*
3
EC-14
Revision: October 2005
INDEX FOR DTC
2005 QX56
FUEL SYS-RICH-B1 P0172 0172 EC-245
FUEL SYS-RICH-B2 P0175 0175 EC-245
HLR/C SOL/CIRC P1767 1767 AT-152
HLR/C SOL FNCTN P1769 1769 AT-154
HO2S2 (B1) P0138 0138 EC-216
HO2S2 (B1) P0139 0139 EC-225
HO2S2 (B1) P1146 1146 EC-415
HO2S2 (B1) P1147 1147 EC-426
HO2S2 (B2) P0158 0158 EC-216
HO2S2 (B2) P0159 0159 EC-225
HO2S2 (B2) P1166 1166 EC-415
HO2S2 (B2) P1167 1167 EC-426
HO2S2 HTR (B1) P0037 0037 EC-166
HO2S2 HTR (B1) P0038 0038 EC-166
HO2S2 HTR (B2) P0057 0057 EC-166
HO2S2 HTR (B2) P0058 0058 EC-166
I/C SOLENOID/CIRC P1752 1752 AT-140
I/C SOLENOID FNCTN P1754 1754 AT-142
IAT SEN/CIRCUIT P0112 0112 EC-191
IAT SEN/CIRCUIT P0113 0113 EC-191
IAT SENSOR P0127 0127 EC-211
ISC SYSTEM P0506 0506 EC-374
ISC SYSTEM P0507 0507 EC-376
KNOCK SEN/CIRC-B1 P0327 0327 EC-279
KNOCK SEN/CIRC-B1 P0328 0328 EC-279
KNOCK SEN/CIRC-B2 P0332 0332 EC-279
KNOCK SEN/CIRC-B2 P0333 0333 EC-279
L/PRESS SOL/CIRC P0745 0745 AT-119
LC/B SOLENOID/CIRC P1772 1772 AT-156
LC/B SOLENOID FNCT P1774 1774 AT-158
MAF SEN/CIRCUIT P0101 0101 EC-174
MAF SEN/CIRCUIT P0102 0102 EC-183
MAF SEN/CIRCUIT P0103 0103 EC-183
MULTI CYL MISFIRE P0300 0300 EC-271
NATS MALFUNCTION P1610 - P1615 1610 - 1615 BL-137
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.
P0000 0000 —
P-N POS SW/CIRCUIT P1706 1706 EC-581
PNP SW/CIRC P0705 0705 AT-104
PURG VOLUME CONT/V P0444 0444 EC-318
PURG VOLUME CONT/V P0445 0445 EC-318
PURG VOLUME CONT/V P1444 1444 EC-531
Items
(CONSULT-II screen terms)
DTC*
1
Reference page
CONSULT-II
GST*
2
ECM*
3
INDEX FOR DTC
EC-15
C
D
E
F
G
H
I
J
K
L
M
A
EC
Revision: October 2005 2005 QX56
*1: 1st trip DTC No. is the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results), this number is controlled by NISSAN.
*4: The troubleshooting for this DTC needs CONSULT-II.
*5: When the fail-safe operations for both self-diagnoses occur, the MIL illuminates.
*6: 2WD models
*7: Models with ICC
PW ST P SEN/CIRC P0550 0550 EC-378
SENSOR POWER/CIRC P1229 1229 EC-454
TCC SOLENOID/CIRC P0740 0740 AT-115
TCM P0700 0700 AT-103
TCS C/U FUNCTN P1211 1211 EC-438
TCS/CIRC P1212 1212 EC-439
THERMSTAT FNCTN P0128 0128 EC-214
TP SEN 1/CIRC P0222 0222 EC-264
TP SEN 1/CIRC P0223 0223 EC-264
TP SEN 2/CIRC P0122 0122 EC-201
TP SEN 2/CIRC P0123 0123 EC-201
TP SENSOR P2135 2135 EC-604
TURBINE REV S/CIRC P1716 1716 AT-131
TW CATALYST SYS-B1 P0420 0420 EC-298
TW CATALYST SYS-B2 P0430 0430 EC-298
VEH SPD SEN/CIR AT*
5
P0720 0720 AT-108
VEH SPEED SEN/CIRC*
5
P0500 0500 EC-372
VENT CONTROL VALVE P0447 0447 EC-325
VENT CONTROL VALVE P1446 1446 EC-539
Items
(CONSULT-II screen terms)
DTC*
1
Reference page
CONSULT-II
GST*
2
ECM*
3
EC-16
Revision: October 2005
PRECAUTIONS
2005 QX56
PRECAUTIONS PFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UBS00KZ0
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
● To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.
● Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
● Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
On Board Diagnostic (OBD) System of Engine and A/T UBS00KZ1
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
● Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves,
etc. will cause the MIL to light up.
● Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
● Certain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector. For description and how to disconnect, refer to PG-67, "
HAR-
NESS CONNECTOR" .
● Be sure to route and secure the harnesses properly after work. The interference of the harness
with a bracket, etc. may cause the MIL to light up due to the short circuit.
● Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.
● Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
Precaution UBS00KZ2
● Always use a 12 volt battery as power source.
● Do not attempt to disconnect battery cables while engine is
running.
● Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative
battery cable. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned OFF.
● Before removing parts, turn ignition switch OFF and then
disconnect battery ground cable.
SEF289H
PRECAUTIONS
EC-17
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EC
Revision: October 2005 2005 QX56
● Do not disassemble ECM.
● If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.
● If the battery is disconnected, the following emission-
related diagnostic information will be lost within 24 hours.
– Diagnostic trouble codes
– 1st trip diagnostic trouble codes
– Freeze frame data
– 1st trip freeze frame data
– System readiness test (SRT) codes
– Test values
● When connecting ECM harness connector, fasten it
securely with a lever as far as it will go as shown in the fig-
ure.
● When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.
● Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.
● Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.
● Keep engine control system parts and harness dry.
● Before replacing ECM, perform ECM Terminals and Refer-
ence Value inspection and make sure ECM functions prop-
erly. Refer to EC-117, "
ECM Terminals and Reference Value"
.
● Handle mass air flow sensor carefully to avoid damage.
● Do not disassemble mass air flow sensor.
● Do not clean mass air flow sensor with any type of deter-
gent.
● Do not disassemble electric throttle control actuator.
● Even a slight leak in the air intake system can cause seri-
ous incidents.
● Do not shock or jar the camshaft position sensor (PHASE), crankshaft position sensor (POS).
PBIB1164E
BBIA0387E
PBIB0090E
MEF040D
EC-18
Revision: October 2005
PRECAUTIONS
2005 QX56
● After performing each TROUBLE DIAGNOSIS, perform DTC
Confirmation Procedure or Overall Function Check.
The DTC should not be displayed in the DTC Confirmation
Procedure if the repair is completed. The Overall Function
Check should be a good result if the repair is completed.
● When measuring ECM signals with a circuit tester, never
allow the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.
● Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
● B1 indicates the bank 1, B2 indicates the bank 2 as shown
in the figure.
SEF217U
SEF348N
PBIB1144E
PRECAUTIONS
EC-19
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● Do not operate fuel pump when there is no fuel in lines.
● Tighten fuel hose clamps to the specified torque.
● Do not depress accelerator pedal when starting.
● Immediately after starting, do not rev up engine unneces-
sarily.
● Do not rev up engine just prior to shutdown.
● When installing C.B. ham radio or a mobile phone, be sure
to observe the following as it may adversely affect elec-
tronic control systems depending on installation location.
– Keep the antenna as far as possible from the electronic
control units.
– Keep the antenna feeder line more than 20 cm (8 in) away
from the harness of electronic controls.
Do not let them run parallel for a long distance.
– Adjust the antenna and feeder line so that the standing-
wave radio can be kept smaller.
– Be sure to ground the radio to vehicle body.
Wiring Diagrams and Trouble Diagnosis UBS00KZ3
When you read wiring diagrams, refer to the following:
● GI-15, "How to Read Wiring Diagrams"
● PG-4, "POWER SUPPLY ROUTING CIRCUIT" for power distribution circuit
When you perform trouble diagnosis, refer to the following:
● GI-11, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES"
● GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident"
BBIA0402E
SEF709Y
SEF708Y
EC-20
Revision: October 2005
PREPARATION
2005 QX56
PREPARATION PFP:00002
Special Service Tools UBS00KZ4
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool name
Description
EG17650301
(J-33984-A)
Radiator cap tester
adapter
Adapting radiator cap tester to radiator cap and ra-
diator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV10117100
(J-36471-A)
Heated oxygen sensor
wrench
Loosening or tightening heated oxygen sensors
with 22 mm (0.87 in) hexagon nut
KV10114400
(J-38365)
Heated oxygen sensor
wrench
Loosening or tightening heated oxygen sensors
a: 22 mm (0.87 in)
(J-44626)
Air fuel ratio (A/F) sen-
sor wrench
Loosening or tightening air fuel ratio (A/F) sensor 1
(J-44321)
Fuel pressure gauge
kit
Checking fuel pressure
(J-44321-6)
Fuel pressure adapter
Connecting fuel pressure gauge to quick connec-
tor type fuel lines.
(J-45488)
Quick connector re-
lease
Remove fuel tube quick connectors in engine
room.
S-NT564
S-NT379
S-NT636
LEM054
LEC642
LBIA0376E
PBIC0198E
PREPARATION
EC-21
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KV109E0010
(J-46209)
Break-out box
Measuring the ECM signals with a circuit tester
KV109E0080
(J-45819)
Y-cable adapter
Measuring the ECM signals with a circuit tester
(J-23688)
Engine coolant refrac-
tometer
Checking concentration of ethylene glycol in en-
gine coolant
Tool number
(Kent-Moore No.)
Tool name
Description
S-NT825
S-NT826
WBIA0539E
EC-22
Revision: October 2005
PREPARATION
2005 QX56
Commercial Service Tools UBS00KZ5
Tool name
(Kent-Moore No.)
Description
Leak detector
i.e.: (J-41416)
Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD)
Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382)
Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant tempera-
ture sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12)
Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL specifica-
tion MIL-A-907)
Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779
ENGINE CONTROL SYSTEM
EC-23
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ENGINE CONTROL SYSTEM PFP:23710
System Diagram UBS00KZ6
PBIB2051E
EC-24
Revision: October 2005
ENGINE CONTROL SYSTEM
2005 QX56
Multiport Fuel Injection (MFI) System UBS00KZ7
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
<Fuel increase>
● During warm-up
● When starting the engine
● During acceleration
● Hot-engine operation
● When selector lever is changed from N to D
● High-load, high-speed operation
<Fuel decrease>
● During deceleration
● During high engine speed operation
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
control
Fuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1
Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2
VDC/TCS operation command
Air conditioner switch*
2
Air conditioner operation
Wheel sensor*
2
Vehicle speed
ENGINE CONTROL SYSTEM
EC-25
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MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses air
fuel ratio (A/F) sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about air
fuel ratio (A/F) sensor 1, refer to EC-459, "
DTC P1271, P1281 A/F SENSOR 1" . This maintains the mixture
ratio within the range of stoichiometric (ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of air fuel ratio (A/F) sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
● Deceleration and acceleration
● High-load, high-speed operation
● Malfunction of A/F sensor 1 or its circuit
● Insufficient activation of A/F sensor 1 at low engine coolant temperature
● High engine coolant temperature
● During warm-up
● After shifting from N to D
● When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from A/F sensor 1.
This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoret-
ical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally
designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-
ing operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-
oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in
fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
SEF503YB
EC-26
Revision: October 2005
ENGINE CONTROL SYSTEM
2005 QX56
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all eight cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The eight injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration, operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speed.
Electronic Ignition (EI) System UBS00KZ8
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 8 - 7 - 3 - 6 - 5 - 4 -2
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of the
engine. The ignition timing data is stored in the ECM.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Comput-
ing this information, ignition signals are transmitted to the power transistor.
During the following conditions, the ignition timing is revised by the ECM according to the other data stored in
the ECM.
● At starting
● During warm-up
● At idle
● At low battery voltage
PBIB0122E
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
2
Piston position
Ignition timing
control
Power transistor
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*
1
Vehicle speed
ENGINE CONTROL SYSTEM
EC-27
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● During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Fuel Cut Control (at No Load and High Engine Speed) UBS00KZ9
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed over is 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-24, "
Multiport Fuel Injection (MFI) System" .
Sensor Input signal to ECM ECM function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut con-
trol
Fuel injector
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed
Wheel sensor* Vehicle speed
EC-28
Revision: October 2005
AIR CONDITIONING CUT CONTROL
2005 QX56
AIR CONDITIONING CUT CONTROL PFP:23710
Input/Output Signal Chart UBS00KZA
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System Description UBS00KZB
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.
● When the accelerator pedal is fully depressed.
● When cranking the engine.
● At high engine speeds.
● When the engine coolant temperature becomes excessively high.
● When operating power steering during low engine speed or low vehicle speed.
● When engine speed is excessively low.
● When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch*
1
Air conditioner ON signal
Air conditioner
cut control
Air conditioner relay
Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor*
1
Vehicle speed
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
EC-29
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AUTOMATIC SPEED CONTROL DEVICE (ASCD) PFP:18930
System Description UBS00KZC
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE indicator and SET indicator in combination meter. If any
malfunction occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE indicator in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET indicator in combination meter illuminates.)
ACCEL OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.
● CANCEL switch is pressed
● More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)
● Brake pedal is depressed
● Selector lever is changed to N, P, R position
● Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed
● VDC system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.
● Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.
● Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed control
Electric throttle control
actuator
Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switch
Gear position
Wheel sensor* Vehicle speed
TCM* Powertrain revolution
EC-30
Revision: October 2005
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
2005 QX56
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.
● Brake pedal is released
● A/T selector lever is in other than P and N positions
● Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component Description UBS00KZD
ASCD STEERING SWITCH
Refer to EC-552 .
ASCD BRAKE SWITCH
Refer to EC-569 , and EC-657 .
STOP LAMP SWITCH
Refer to EC-569 , EC-586 and EC-657 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-397 , EC-399 , EC-405 and EC-410 .
ASCD INDICATOR
Refer to EC-664 .
CAN COMMUNICATION
EC-31
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CAN COMMUNICATION PFP:23710
System Description UBS00KZE
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
Refer to LAN-5, "
CAN COMMUNICATION" , about CAN communication for detail.
EC-32
Revision: October 2005
EVAPORATIVE EMISSION SYSTEM
2005 QX56
EVAPORATIVE EMISSION SYSTEM PFP:14950
Description UBS00KZF
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
PBIB1631E
EVAPORATIVE EMISSION SYSTEM
EC-33
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EVAPORATIVE EMISSION LINE DRAWING
PBIB2053E
EC-34
Revision: October 2005
EVAPORATIVE EMISSION SYSTEM
2005 QX56
BBIA0444E
EVAPORATIVE EMISSION SYSTEM
EC-35
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Component Inspection UBS00KZG
EVAP CANISTER
Check EVAP canister as follows:
1. Block port B .
2. Blow air into port A and check that it flows freely out of port C .
3. Release blocked port B .
4. Apply vacuum pressure to port B and check that vacuum pres-
sure exists at the ports A and C .
5. Block port A and B .
6. Apply pressure to port C and check that there is no leakage.
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)
1. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
3. If out of specification, replace fuel filler cap as an assembly.
CAUTION:
Use only a genuine fuel filler cap as a replacement. If an incor-
rect fuel filler cap is used, the MIL may come on.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-318 and EC-531 .
FUEL TANK TEMPERATURE SENSOR
Refer to EC-253 and EC-259 .
EVAP CANISTER VENT CONTROL VALVE
Refer to EC-325 and EC-539 .
EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-332 , EC-335 and EC-341 .
PBIB1212E
SEF445Y
Pressure:
15.3 - 20.0 kPa (0.156 - 0.204 kg/cm
2
, 2.22
- 2.90 psi)
Vacuum:
−6.0 to −3.3 kPa (−0.061 to −0.034 kg/cm
2
,
−0.87 to −0.48 psi)
SEF943S
EC-36
Revision: October 2005
EVAPORATIVE EMISSION SYSTEM
2005 QX56
EVAP SERVICE PORT
Positive pressure is delivered to the EVAP system through the EVAP
service port. If fuel vapor leakage in the EVAP system occurs, use a
leak detector to locate the leak.
Removal and Installation UBS00KZH
EVAP CANISTER
Tighten EVAP canister as shown in the figure.
EVAP CANISTER VENT CONTROL VALVE
1. Turn EVAP canister vent control valve counterclockwise.
2. Remove the EVAP canister vent control valve.
Always replace O-ring with a new one.
BBIA0366E
: N-·m (kg-m, in-lb)
BBIA0349E
BBIA0350E
EVAPORATIVE EMISSION SYSTEM
EC-37
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How to Detect Fuel Vapor Leakage UBS00KZI
CAUTION:
● Never use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pressure in EVAP system.
NOTE:
● Do not start engine.
● Improper installation of EVAP service port adapter to the EVAP service port may cause a leak.
WITH CONSULT-II
1. Attach the EVAP service port adapter securely to the EVAP service port.
2. Also attach the pressure pump and hose to the EVAP service port adapter.
3. Turn ignition switch ON.
4. Select the “EVAP SYSTEM CLOSE” of “WORK SUPPORT
MODE” with CONSULT-II.
5. Touch “START”. A bar graph (Pressure indicating display) will
appear on the screen.
6. Apply positive pressure to the EVAP system until the pressure
indicator reaches the middle of the bar graph.
7. Remove EVAP service port adapter and hose with pressure
pump.
8. Locate the leak using a leak detector. Refer to EC-33, "
EVAPO-
RATIVE EMISSION LINE DRAWING" .
PEF838U
PEF917U
SEF200U
EC-38
Revision: October 2005
EVAPORATIVE EMISSION SYSTEM
2005 QX56
WITHOUT CONSULT-II
1. Attach the EVAP service port adapter securely to the EVAP ser-
vice port.
2. Also attach the pressure pump with pressure gauge to the EVAP
service port adapter.
3. Apply battery voltage between the terminals of EVAP canister vent control valve to make a closed EVAP
system.
4. To locate the leak, deliver positive pressure to the EVAP system until pressure gauge points reach 1.38 to
2.76 kPa (0.014 to 0.028 kg/cm
2
, 0.2 to 0.4 psi).
5. Remove EVAP service port adapter and hose with pressure pump.
6. Locate the leak using a leak detector. Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
BBIA0366E
SEF462UA
BBIA0443E
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
EC-39
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ON BOARD REFUELING VAPOR RECOVERY (ORVR) PFP:00032
System Description UBS00KZJ
From the beginning of refueling, the air and vapor inside the fuel tank go through refueling EVAP vapor cut
valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and the air is
released to the atmosphere.
When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed and
refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is purged
during driving.
WARNING:
When conducting inspections below, be sure to observe the following:
● Put a “CAUTION: INFLAMMABLE” sign in workshop.
● Do not smoke while servicing fuel system. Keep open flames and sparks away from work area.
● Be sure to furnish the workshop with a CO2 fire extinguisher.
CAUTION:
● Before removing fuel line parts, carry out the following procedures:
– Put drained fuel in an explosion-proof container and put lid on securely.
– Release fuel pressure from fuel line. Refer to EC-93, "FUEL PRESSURE RELEASE" .
– Disconnect battery ground cable.
● Always replace O-ring when the fuel gauge retainer is removed.
● Do not kink or twist hose and tube when they are installed.
● Do not tighten hose and clamps excessively to avoid damaging hoses.
● After installation, run engine and check for fuel leaks at connection.
● Do not attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.
PBIB1068E
EC-40
Revision: October 2005
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
2005 QX56
Diagnostic Procedure UBS00KZK
SYMPTOM: FUEL ODOR FROM EVAP CANISTER IS STRONG.
1. CHECK EVAP CANISTER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Weigh the EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK IF EVAP CANISTER SATURATED WITH WATER
Does water drain from the EVAP canister?
Yes or No
Yes >> GO TO 3.
No >> GO TO 5.
3. REPLACE EVAP CANISTER
Replace EVAP canister with a new one.
>> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the EVAP hose between EVAP canister and vehicle frame for clogging or poor connection.
>> Repair or replace EVAP hose.
5. CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-43, "
Component Inspection" .
OK or NG
OK >> INSPECTION END
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
BBIA0351E
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
EC-41
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SYMPTOM: CANNOT REFUEL/FUEL ODOR FROM THE FUEL FILLER OPENING IS STRONG
WHILE REFUELING.
1. CHECK EVAP CANISTER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Weigh the EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK IF EVAP CANISTER SATURATED WITH WATER
Does water drain from the EVAP canister?
Yes or No
Yes >> GO TO 3.
No >> GO TO 5.
3. REPLACE EVAP CANISTER
Replace EVAP canister with a new one.
>> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the EVAP hose between EVAP canister and vehicle frame for clogging or poor connection.
>> Repair or replace EVAP hose.
5. CHECK VENT HOSES AND VENT TUBES
Check hoses and tubes between EVAP canister and refueling EVAP vapor cut valve for clogging, kink, loose-
ness and improper connection.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace hoses and tubes.
6. CHECK FILLER NECK TUBE
Check recirculation line for clogging, dents and cracks.
OK or NG
OK >> GO TO 7.
NG >> Replace filler neck tube.
BBIA0351E
EC-42
Revision: October 2005
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
2005 QX56
7. CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-43, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
8. CHECK FUEL FILLER TUBE
Check filler neck tube and hose connected to the fuel tank for clogging, dents and cracks.
OK or NG
OK >> GO TO 9.
NG >> Replace fuel filler tube.
9. CHECK ONE-WAY FUEL VALVE-I
Check one-way valve for clogging.
OK or NG
OK >> GO TO 10.
NG >> Repair or replace one-way fuel valve with fuel tank.
10. CHECK ONE-WAY FUEL VALVE-II
1. Make sure that fuel is drained from the tank.
2. Remove fuel filler tube and hose.
3. Check one-way fuel valve for operation as follows.
When a stick is inserted, the valve should open, when removing
stick it should close.
Do not drop any material into the tank.
OK or NG
OK >> INSPECTION END
NG >> Replace fuel filler tube or replace one-way fuel valve
with fuel tank.
SEF665U
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
EC-43
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Component Inspection UBS00KZL
REFUELING EVAP VAPOR CUT VALVE
With CONSULT-II
1. Remove fuel tank. Refer to FL-9, "FUEL TANK" .
2. Drain fuel from the tank as follows:
a. Remove fuel feed hose located on the fuel gauge retainer.
b. Connect a spare fuel hose, one side to fuel gauge retainer where the hose was removed and the other
side to a fuel container.
c. Drain fuel using “FUEL PUMP RELAY” in “ACTIVE TEST” mode with CONSULT-II.
3. Check refueling EVAP vapor cut valve for being stuck to close as follows.
Blow air into the refueling EVAP vapor cut valve (from the end of EVAP/ORVR line hose), and check that
the air flows freely into the tank.
4. Check refueling EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose end.
b. Remove fuel gauge retainer with fuel gauge unit.
Always replace O-ring with new one.
c. Put fuel tank upside down.
d. Apply vacuum pressure to hose end [−13.3 kPa (−100 mmHg, −3.94 inHg)] with fuel gauge retainer
remaining open and check that the pressure is applicable.
Without CONSULT-II
1. Remove fuel tank. Refer to FL-9, "FUEL TANK" .
2. Drain fuel from the tank as follows:
a. Remove fuel gauge retainer.
b. Drain fuel from the tank using a handy pump into a fuel container.
3. Check refueling EVAP vapor cut valve for being stuck to close as follows.
Blow air into the refueling EVAP vapor cut valve (from the end of EVAP/ORVR line hose), and check that
the air flows freely into the tank.
4. Check refueling EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose end.
b. Remove fuel gauge retainer with fuel gauge unit.
Always replace O-ring with new one.
c. Put fuel tank upside down.
BBIA0401E
EC-44
Revision: October 2005
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
2005 QX56
d. Apply vacuum pressure to hose end [−13.3 kPa (−100 mmHg, −3.94 inHg)] with fuel gauge retainer
remaining open and check that the pressure is applicable.
BBIA0401E
POSITIVE CRANKCASE VENTILATION
EC-45
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POSITIVE CRANKCASE VENTILATION PFP:11810
Description UBS00KZM
SYSTEM DESCRIPTION
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake
manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the
PCV valve. Normally, the capacity of the valve is sufficient to handle any blow-by and a small amount of venti-
lating air. The ventilating air is then drawn from the air inlet tubes into the crankcase. In this process the air
passes through the hose connecting air inlet tubes to rocker cover. Under full-throttle condition, the manifold
vacuum is insufficient to draw the blow-by flow through the valve. The flow goes through the hose connection
in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not
meet the requirement. This is because some of the flow will go
through the hose connection to the air inlet tubes under all condi-
tions.
Component Inspection UBS00KZN
PCV (POSITIVE CRANKCASE VENTILATION) VALVE
With engine running at idle, remove PCV valve from rocker cover. A
properly working valve makes a hissing noise as air passes through
it. A strong vacuum should be felt immediately when a finger is
placed over valve inlet.
PBIB0062E
PBIB1588E
PBIB1589E
EC-46
Revision: October 2005
POSITIVE CRANKCASE VENTILATION
2005 QX56
PCV VALVE VENTILATION HOSE
1. Check hoses and hose connections for leaks.
2. Disconnect all hoses and clean with compressed air. If any hose
cannot be freed of obstructions, replace.
S-ET277
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS)
EC-47
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IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS) PFP:28591
Description UBS00L1L
● If the security indicator lights up with the ignition switch in
the ON position or “NATS MALFUNCTION” is displayed on
“SELF-DIAG RESULTS” screen, perform self-diagnostic
results mode with CONSULT-II using NATS program card.
Refer to BL-137, "
IVIS (INFINITI VEHICLE IMMOBILIZER
SYSTEM-NATS)" .
● Confirm no self-diagnostic results of IVIS (NATS) is dis-
played before touching “ERASE” in “SELF-DIAG RESULTS”
mode with CONSULT-II.
● When replacing ECM, initialization of IVIS (NATS) system
and registration of all IVIS (NATS) ignition key IDs must be
carried out with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner. Regarding the procedures of IVIS (NATS)
initialization and IVIS (NATS) ignition key ID registration, refer to CONSULT-II operation manual,
IVIS/NVIS.
SEF543X
EC-48
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
ON BOARD DIAGNOSTIC (OBD) SYSTEM PFP:00028
Introduction UBS00KZP
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
The above information can be checked using procedures listed in the table below.
×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator lamp (MIL) on the instrument panel lights up when the same malfunction is detected
in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-103,
"Fail-safe Chart" .)
Two Trip Detection Logic UBS00KZQ
When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Emission-related diagnostic information Diagnostic service
Diagnostic Trouble Code (DTC) Service $03 of SAE J1979
Freeze Frame data Service $02 of SAE J1979
System Readiness Test (SRT) code Service $01 of SAE J1979
1st Trip Diagnostic Trouble Code (1st Trip DTC) Service $07 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limits Service $06 of SAE J1979
Calibration ID Service $09 of SAE J1979
DTC 1st trip DTC
Freeze
Frame data
1st trip Freeze
Frame data
SRT code SRT status Test value
CONSULT-II ×× × × ××—
GST ×× × — ×××
ECM ××*— — — × —
Items
MIL DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying
2nd trip
displaying
1st trip
displaying
2nd trip
display-
ing
Blinking
Lighting
up
Blinking
Lighting
up
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0308 is being detected
× ————— × —
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0308 is being detected
—— × —— × ——
One trip detection diagnoses
(Refer to EC-49, "
EMISSION-
RELATED DIAGNOSTIC INFOR-
MATION ITEMS" .)
— × —— × ———
Except above — — — × — ××—
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-49
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Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
Emission-related Diagnostic Information UBS00KZR
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
×:Applicable —: Not applicable
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
Items
(CONSULT-II screen terms)
DTC*
1
SRT code
Test value/
Test limit
(GST only)
Trip MIL
Refer-
ence page
CONSULT-II
GST*
2
ECM*
3
CAN COMM CIRCUIT U1000
1000*
5
—— 1 × EC-163
CAN COMM CIRCUIT U1001
1001*
5
—— 2 —EC-163
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.
P0000 0000 ———
Flashing*
7
EC-65
HO2S2 HTR (B1) P0037 0037 ××2 × EC-166
HO2S2 HTR (B1) P0038 0038 ××2 × EC-166
HO2S2 HTR (B2) P0057 0057 ××2 × EC-166
HO2S2 HTR (B2) P0058 0058 ××2 × EC-166
MAF SEN/CIRCUIT P0101 0101 — — 2 × EC-174
MAF SEN/CIRCUIT P0102 0102 — — 1 × EC-183
MAF SEN/CIRCUIT P0103 0103 — — 1 × EC-183
IAT SEN/CIRCUIT P0112 0112 — — 2 × EC-191
IAT SEN/CIRCUIT P0113 0113 — — 2 × EC-191
ECT SEN/CIRCUIT P0117 0117 — — 1 × EC-195
ECT SEN/CIRCUIT P0118 0118 — — 1 × EC-195
TP SEN 2/CIRC P0122 0122 — — 1 × EC-201
TP SEN 2/CIRC P0123 0123 — — 1 × EC-201
ECT SENSOR P0125 0125 — — 1 × EC-208
IAT SENSOR P0127 0127 — — 2 × EC-211
THERMSTAT FNCTN P0128 0128 — — 2 × EC-214
HO2S2 (B1) P0138 0138 — × 2 × EC-216
HO2S2 (B1) P0139 0139 ××2 × EC-225
HO2S2 (B2) P0158 0158 — × 2 × EC-216
HO2S2 (B2) P0159 0159 ××2 × EC-225
FUEL SYS-LEAN-B1 P0171 0171 — — 2 × EC-236
FUEL SYS-RICH-B1 P0172 0172 — — 2 × EC-245
FUEL SYS-LEAN-B2 P0174 0174 — — 2 × EC-236
FUEL SYS-RICH-B2 P0175 0175 — — 2 × EC-245
FTT SENSOR P0181 0181 — — 2 × EC-253
FTT SEN/CIRCUIT P0182 0182 — — 2 × EC-259
FTT SEN/CIRCUIT P0183 0183 — — 2 × EC-259
TP SEN 1/CIRC P0222 0222 — — 1 × EC-264
TP SEN 1/CIRC P0223 0223 — — 1 × EC-264
MULTI CYL MISFIRE P0300 0300 — — 2 × EC-271
EC-50
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
CYL 1 MISFIRE P0301 0301 — — 2 × EC-271
CYL 2 MISFIRE P0302 0302 — — 2 × EC-271
CYL 3 MISFIRE P0303 0303 — — 2 × EC-271
CYL 4 MISFIRE P0304 0304 — — 2 × EC-271
CYL 5 MISFIRE P0305 0305 — — 2 × EC-271
CYL 6 MISFIRE P0306 0306 — — 2 × EC-271
CYL 7 MISFIRE P0307 0307 — — 2 × EC-271
CYL 8 MISFIRE P0308 0308 — — 2 × EC-271
KNOCK SEN/CIRC-B1 P0327 0327 — — 2 — EC-279
KNOCK SEN/CIRC-B1 P0328 0328 — — 2 — EC-279
KNOCK SEN/CIRC-B2 P0332 0332 — — 2 — EC-279
KNOCK SEN/CIRC-B2 P0333 0333 — — 2 — EC-279
CKP SEN/CIRCUIT P0335 0335 — — 2 × EC-284
CMP SEN/CIRC-B1 P0340 0340 — — 2 × EC-291
TW CATALYST SYS-B1 P0420 0420 ××2 × EC-298
TW CATALYST SYS-B2 P0430 0430 ××2 × EC-298
EVAP PURG FLOW/MON P0441 0441 ××2 × EC-304
EVAP SMALL LEAK P0442 0442 ××2 × EC-309
PURG VOLUME CONT/V P0444 0444 — — 2 × EC-318
PURG VOLUME CONT/V P0445 0445 — — 2 × EC-318
VENT CONTROL VALVE P0447 0447 — — 2 × EC-325
EVAP SYS PRES SEN P0451 0451 — — 2 × EC-332
EVAP SYS PRES SEN P0452 0452 — — 2 × EC-335
EVAP SYS PRES SEN P0453 0453 — — 2 × EC-341
EVAP GROSS LEAK P0455 0455 — — 2 × EC-349
EVAP VERY SML LEAK P0456 0456
×*
4
× 2 × EC-357
FUEL LEV SEN SLOSH P0460 0460 — — 2 × EC-366
FUEL LEVEL SENSOR P0461 0461 — — 2 × EC-368
FUEL LEVL SEN/CIRC P0462 0462 — — 2 × EC-370
FUEL LEVL SEN/CIRC P0463 0463 — — 2 × EC-370
VEH SPEED SEN/CIRC*
6
P0500 0500 — — 2 × EC-372
ISC SYSTEM P0506 0506 — — 2 × EC-374
ISC SYSTEM P0507 0507 — — 2 × EC-376
PW ST P SEN/CIRC P0550 0550 — — 2 — EC-378
ECM P0605 0605 — — 1 or 2 × or — EC-383
TCM P0700 0700 — — 1 × AT-103
PNP SW/CIRC P0705 0705 — — 2 × AT-104
ATF TEMP SEN/CIRC P0710 0710 — — 2 × AT-126
VHCL SPD SEN/CIR AT*
6
P0720 0720 — — 1 × AT-115
TCC SOLENOID/CIRC P0740 0740 — — 2 × AT-115
A/T TCC S/U FNCTN P0744 0744 — — 2 × AT-117
L/PRESS SOL/CIRC P0745 0745 — — 2 × AT-119
Items
(CONSULT-II screen terms)
DTC*
1
SRT code
Test value/
Test limit
(GST only)
Trip MIL
Refer-
ence page
CONSULT-II
GST*
2
ECM*
3
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-51
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A/F SEN1 HTR (B1) P1031 1031 ××2 × EC-386
A/F SEN1 HTR (B1) P1032 1032 ××2 × EC-386
A/F SEN1 HTR (B2) P1051 1051 ××2 × EC-386
A/F SEN1 HTR (B2) P1052 1052 ××2 × EC-386
ECM BACK UP/CIRC P1065 1065 — — 2 × EC-393
ETC ACTR P1121 1121 — — 1 × EC-397
ETC FUNCTION/CIRC P1122 1122 — — 1 × EC-399
ETC MOT PWR P1124 1124 — — 1 × EC-405
ETC MOT PWR P1126 1126 — — 1 × EC-405
ETC MOT P1128 1128 — — 1 × EC-410
HO2S2 (B1) P1146 1146 ××2 × EC-415
HO2S2 (B1) P1147 1147 ××2 × EC-426
CLOSED LOOP-B1 P1148 1148 — — 1 × EC-437
HO2S2 (B2) P1166 1166 ××2 × EC-415
HO2S2 (B2) P1167 1167 ××2 × EC-426
CLOSED LOOP-B2 P1168 1168 — — 1 × EC-437
TCS C/U FUNCTN P1211 1211 — — 2 — EC-438
TCS/CIRC P1212 1212 — — 2 — EC-439
ENG OVER TEMP P1217 1217 — — 1 × EC-440
CTP LEARNING P1225 1225 — — 2 — EC-450
CTP LEARNING P1226 1226 — — 2 — EC-452
SENSOR POWER/CIRC P1229 1229 — — 1 × EC-454
A/F SENSOR1 (B1) P1271 1271 — × 2 × EC-459
A/F SENSOR1 (B1) P1272 1272 — × 2 × EC-468
A/F SENSOR1 (B1) P1273 1273 — × 2 × EC-477
A/F SENSOR1 (B1) P1274 1274 — × 2 × EC-487
A/F SENSOR1 (B1) P1276 1276 — × 2 × EC-497
A/F SENSOR1 (B1) P1278 1278 ××2 × EC-507
A/F SENSOR1 (B1) P1279 1279 ××2 × EC-519
A/F SENSOR1 (B2) P1281 1281 — × 2 × EC-459
A/F SENSOR1 (B2) P1282 1282 — × 2 × EC-468
A/F SENSOR1 (B2) P1283 1283 — × 2 × EC-477
A/F SENSOR1 (B2) P1284 1284 — × 2 × EC-487
A/F SENSOR1 (B2) P1286 1286 — × 2 × EC-497
A/F SENSOR1 (B2) P1288 1288 ××2 × EC-507
A/F SENSOR1 (B2) P1289 1289 ××2 × EC-519
PURG VOLUME CONT/V P1444 1444 — — 2 × EC-531
VENT CONTROL VALVE P1446 1446 — — 2 × EC-539
Items
(CONSULT-II screen terms)
DTC*
1
SRT code
Test value/
Test limit
(GST only)
Trip MIL
Refer-
ence page
CONSULT-II
GST*
2
ECM*
3
EC-52
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
*1: 1st trip DTC No. is the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results), this number is controlled by NISSAN.
*4: SRT code will not be set if the self-diagnostic result is NG.
*5: The troubleshooting for this DTC needs CONSULT-II.
*6: When the fail-safe operations for both self-diagnoses occur at the same time, the MIL illuminates.
ASCD SW P1564 1564 — — 1 —
EC-545
(Models
with ICC)
EC-552
(Models
with
ASCD)
ACC COMMAND VALUE*
9
P1568 1568 — — 1 — EC-559
ASCD BRAKE SW P1572 1572 — — 1 —
EC-560
(Models
with ICC)
EC-569
(Models
with
ASCD)
ASCD VHL SPD SEN*
8
P1574 1574 — — 1 —
EC-577
(Models
with ICC)
EC-579
(Models
with
ASCD)
NATS MALFUNCTION
P1610 -
P1615
1610 - 1615 — — 2 — BL-137
P-N POS SW/CIRCUIT P1706 1706 — — 2 × EC-581
TURBINE REV S/CIRC P1716 1716 — — 2 × AT-131
A/T INTERLOCK P1730 1730 — — 1 × AT-135
I/C SOLENOID/CIRC P1752 1752 — — 1 × AT-140
I/C SOLENOID FNCTN P1754 1754 — — 1 × AT-142
FR/B SOLENOID/CIRC P1757 1757 — — 1 × AT-144
FR/B SOLENOID FNCT P1759 1759 — — 1 × AT-146
D/C SOLENOID/CIRC P1762 1762 — — 1 × AT-148
D/C SOLENOID FNCTN P1764 1764 — — 1 × AT-150
HLR/C SOL/CIRC P1767 1767 — — 1 × AT-152
HLR/C SOL FNCTN P1769 1769 — — 1 × AT-154
LC/B SOLENOID/CIRC P1772 1772 — — 1 × AT-156
LC/B SOLENOID FNCT P1774 1774 — — 1 × AT-158
BRAKE SW/CIRCUIT P1805 1805 — — 2 — EC-586
APP SEN 1/CIRC P2122 2122 — — 1 × EC-591
APP SEN 1/CIRC P2123 2123 — — 1 × EC-591
APP SEN 2/CIRC P2127 2127 — — 1 × EC-597
APP SEN 2/CIRC P2128 2128 — — 1 × EC-597
TP SENSOR P2135 2135 — — 1 × EC-604
APP SENSOR P2138 2138 — — 1 × EC-611
Items
(CONSULT-II screen terms)
DTC*
1
SRT code
Test value/
Test limit
(GST only)
Trip MIL
Refer-
ence page
CONSULT-II
GST*
2
ECM*
3
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-53
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*7: When the ECM is in the mode of displaying SRT status, MIL may flash. For the details, refer to EC-57, "How to Display SRT Status" .
*8: 2WD models
*9: Models with ICC
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in EC-62, "
HOW
TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .
For malfunctions in which 1st trip DTCs are displayed, refer to EC-49, "
EMISSION-RELATED DIAGNOSTIC
INFORMATION ITEMS" . These items are required by legal regulations to continuously monitor the system/
component. In addition, the items monitored non-continuously are also displayed on CONSULT-II.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-96, "
WORK FLOW" . Then perform DTC Confir-
mation Procedure or Overall Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P1148, P1706, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 1148, 1706, etc.
These DTCs are controlled by NISSAN.
● 1st trip DTC No. is the same as DTC No.
● Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times
the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
EC-54
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, see EC-130, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (Priority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in EC-62, "
HOW TO ERASE EMIS-
SION-RELATED DIAGNOSTIC INFORMATION" .
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
PBIB0911E
Priority Items
1
Freeze frame data Misfire — DTC: P0300 - P0308
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MIL is ON during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the priority for
models with CONSULT-II.
SRT Set Timing
SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is
done regardless of whether the result is OK or NG. The set timing is different between OK and NG results and
is shown in the table below.
OK: Self-diagnosis is carried out and the result is OK.
SRT item
(CONSULT-II indication)
Performance
Priority*
Required self-diagnostic items to set the SRT to “CMPLT”
Corresponding
DTC No.
CATALYST 2 Three way catalyst function P0420, P0430
EVAP SYSTEM 2 EVAP control system purge flow monitoring P0441
1 EVAP control system P0442
2 EVAP control system P0456
HO2S 2 Air fuel ratio (A/F) sensor 1 P1278, P1288
Air fuel ratio (A/F) sensor 1 P1279, P1289
Heated oxygen sensor 2 P0139, P0159
Heated oxygen sensor 2 P1146, P1166
Heated oxygen sensor 2 P1147, P1167
HO2S HTR 2 Air fuel ratio (A/F) sensor 1 heater P1031, P1032,
P1051, P1052
Heated oxygen sensor 2 heater P0037, P0038,
P0057, P0058
Self-diagnosis result
Example
Diagnosis
Ignition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400 OK (1) — (1) OK (2) — (2)
P0402 OK (1) — (1) — (1) OK (2)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400 OK (1) — (1) — (1) — (1)
P0402 — (0) — (0) OK (1) — (1)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”
NG exists Case 3 P0400 OK OK — —
P0402 — — — —
P1402 NG — NG
NG
(Consecutive
NG)
(1st trip)
DTC
1st trip DTC — 1st trip DTC
DTC
(= MIL ON)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”
EC-56
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
NG: Self-diagnosis is carried out and the result is NG.
—: Self-diagnosis is not carried out.
When all SRT related self-diagnoses showed OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will
indicate “CMPLT”. → Case 1 above
When all SRT related self-diagnoses showed OK results through several different cycles, the SRT will indicate
“CMPLT” at the time the respective self-diagnoses have at least one OK result. → Case 2 above
If one or more SRT related self-diagnoses showed NG results in 2 consecutive cycles, the SRT will also indi-
cate “CMPLT”. → Case 3 above
The table above shows that the minimum number of cycles for setting SRT as “INCMP” is one (1) for each
self-diagnosis (Case 1 & 2) or two (2) for one of self-diagnoses (Case 3). However, in preparation for the state
emissions inspection, it is unnecessary for each self-diagnosis to be executed twice (Case 3) for the following
reasons:
● The SRT will indicate “CMPLT” at the time the respective self-diagnoses have one (1) OK result.
● The emissions inspection requires “CMPLT” of the SRT only with OK self-diagnosis results.
● When, during SRT driving pattern, 1st trip DTC (NG) is detected prior to “CMPLT” of SRT, the self-diagno-
sis memory must be erased from ECM after repair.
● If the 1st trip DTC is erased, all the SRT will indicate “INCMP”.
NOTE:
SRT can be set as “CMPLT” together with the DTC(s). Therefore, DTC check must always be carried out
prior to the state emission inspection even though the SRT indicates “CMPLT”.
SRT Service Procedure
If a vehicle has failed the state emissions inspection due to one or more SRT items indicating “INCMP”, review
the flowchart diagnostic sequence on the next page.
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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How to Display SRT Status
WITH CONSULT-II
Selecting “SRT STATUS” in “DTC CONFIRMATION” mode with
CONSULT-II.
For items whose SRT codes are set, a “CMPLT” is displayed on the
CONSULT-II screen; for items whose SRT codes are not set,
“INCMP” is displayed.
A sample of CONSULT-II display for SRT code is shown at right.
“INCMP” means the self-diagnosis is incomplete and SRT is not set.
“CMPLT” means the self-diagnosis is complete and SRT is set.
WITH GST
Selecting Service $01 with GST (Generic Scan Tool)
*1 EC-53, "How to Read DTC and 1st
Trip DTC"
*2 EC-57, "How to Display SRT Status" *3 EC-58, "How to Set SRT Code"
PBIB2320E
SEF935Z
EC-58
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
NO TOOLS
A SRT code itself can not be displayed while only SRT status can be.
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown below.
● When all SRT codes are set, MIL lights up continuously.
● When any SRT codes are not set, MIL will flash periodically for 10 seconds.
How to Set SRT Code
To set all SRT codes, self-diagnosis for the items indicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
WITH CONSULT-II
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on EC-55, "
SRT Item" .
WITHOUT CONSULT-II
The most efficient driving pattern in which SRT codes can be properly set is explained on the next page. The
driving pattern should be performed one or more times to set all SRT codes.
PBIB2317E
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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Driving Pattern
PBIB2314E
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
● The time required for each diagnosis varies with road surface conditions, weather, altitude, individual driv-
ing habits, etc.
Zone A refers to the range where the time, required for the diagnosis under normal conditions*, is the
shortest.
Zone B refers to the range where the diagnosis can still be performed if the diagnosis is not completed
within zone A.
*: Normal conditions refer to the following:
● Sea level
● Flat road
● Ambient air temperature: 20 - 30°C (68 - 86°F)
● Diagnosis is performed as quickly as possible under normal conditions.
Under different conditions [For example: ambient air temperature other than 20 - 30°C (68 - 86° F)], diag-
nosis may also be performed.
Pattern 1:
● The engine is started at the engine coolant temperature of −10 to 35°C (14 to 95°F)
(where the voltage between the ECM terminal 73 and ground is 3.0 - 4.3V).
● The engine must be operated at idle speed until the engine coolant temperature is greater than
70°C (158°F) (where the voltage between the ECM terminal 73 and ground is lower than 1.4V).
● The engine is started at the fuel tank temperature of warmer than 0°C (32° F) (where the voltage
between the ECM terminal 107 and ground is less than 4.1V).
Pattern 2:
● When steady-state driving is performed again even after it is interrupted, each diagnosis can be con-
ducted. In this case, the time required for diagnosis may be extended.
Pattern 3:
● Operate vehicle following the driving pattern shown in the figure.
● Release the accelerator pedal during decelerating vehicle speed
from 90 km/h (56 MPH) to 0 km/h (0 MPH).
Pattern 4:
● The accelerator pedal must be held very steady during steady-
state driving.
● If the accelerator pedal is moved, the test must be conducted all
over again.
*1: Depress the accelerator pedal until vehicle speed is 90 km/h (56
MPH), then release the accelerator pedal and keep it released for
more than 10 seconds. Depress the accelerator pedal until vehicle
speed is 90 km/h (56 MPH) again.
*2: Checking the vehicle speed with GST is advised.
Suggested Transmission Gear Position
Set the selector lever in the D position with the overdrive switch turned ON.
PBIB2244E
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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TEST VALUE AND TEST LIMIT (GST ONLY — NOT APPLICABLE TO CONSULT-II)
The following is the information specified in Service $06 of SAE J1979.
The test value is a parameter used to determine whether a system/circuit diagnostic test is OK or NG while
being monitored by the ECM during self-diagnosis. The test limit is a reference value which is specified as the
maximum or minimum value and is compared with the test value being monitored.
These data (test value and test limit) are specified by Test ID (TID) and Component ID (CID) and can be dis-
played on the GST screen.
Item Self-diagnostic test item DTC
Test value (GST display)
Test limit Conversion
TID CID
CATALYST
Three way catalyst function (Bank 1)
P0420 01H 01H Max. 1/128
P0420 02H 81H Min. 1
Three way catalyst function (Bank 2)
P0430 03H 02H Max. 1/128
P0430 04H 82H Min. 1
EVAP
SYSTEM
EVAP control system (Small leak) P0442 05H 03H Max.
1/128 mm
2
EVAP control system purge flow monitoring P0441 06H 83H Min. 20 mV
EVAP control system (Very small leak) P0456 07H 03H Max.
1/128 mm
2
HO2S
Air fuel ratio (A/F) sensor 1 (Bank 1)
P1271 41H 8EH Min. 5mV
P1272 42H 0EH Max. 5mV
P1273 43H 0EH Max. 0.002
P1274 44H 8EH Min. 0.002
P1278 45H 8EH Min. 0.004
P1276 46H 0EH Max. 5mV
P1276 47H 8EH Min. 5mV
P1279 48H 8EH Min. 0.004
Air fuel ratio (A/F) sensor 1 (Bank 2)
P1281 4CH 8FH Min. 5mV
P1282 4DH 0FH Max. 5mV
P1283 4EH 0FH Max. 0.002
P1284 4FH 8FH Min. 0.002
P1288 50H 8FH Min. 0.004
P1286 51H 0FH Max. 5mV
P1286 52H 8FH Min. 5mV
P1289 53H 8FH Min. 0.004
Heated oxygen sensor 2 (Bank 1)
P0138 1CH 06H Max. 10mV
P0139 19H 86H Min. 10mV/500 ms
P1147 1AH 86H Min. 10 mV
P1146 1BH 06H Max. 10 mV
Heated oxygen sensor 2 (Bank 2)
P0158 24H 07H Max. 10mV
P0159 21H 87H Min. 10 mV/500 ms
P1167 22H 87H Min. 10 mV
P1166 23H 07H Max. 10 mV
EC-62
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION
How to Erase DTC
WITH CONSULT-II
The emission related diagnostic information in the ECM can be erased by selecting “ERASE” in the “SELF-
DIAG RESULTS” mode with CONSULT-II.
If DTCs are displayed for both ECM and TCM (Transmission control module), they need to be erased individu-
ally from the ECM and TCM (Transmission control module).
NOTE:
If the DTC is not for A/T related items (see EC-8, "
INDEX FOR DTC" ), skip steps 2 through 4.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Turn CONSULT-II ON and touch “A/T”.
3. Touch “SELF-DIAG RESULTS”.
4. Touch “ERASE”. [The DTC in the TCM (Transmission control module) will be erased.] Then touch “BACK”
twice.
5. Touch “ENGINE”.
6. Touch “SELF-DIAG RESULTS”.
7. Touch “ERASE”. (The DTC in the ECM will be erased.)
HO2S
HEATER
A/F sensor 1 heater (Bank 1)
P1032 57H 10H Max. 5 mV
P1031 58H 90H Min. 5 mV
A/F sensor 1 heater (Bank 2)
P1052 59H 11H Max. 5 mV
P1051 5AH 91H Min. 5 mV
Heated oxygen sensor 2 heater (Bank 1)
P0038 2DH 0AH Max. 20 mV
P0037 2EH 8AH Min. 20 mV
Heated oxygen sensor 2 heater (Bank 2)
P0058 2FH 0BH Max. 20 mV
P0057 30H 8BH Min. 20 mV
Item Self-diagnostic test item DTC
Test value (GST display)
Test limit Conversion
TID CID
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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WITH GST
The emission related diagnostic information in the ECM can be erased by selecting Service $04 with GST.
NOTE:
If the DTC is not for A/T related items (see EC-8, "
INDEX FOR DTC" ), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Perform AT-37, "
OBD-II Diagnostic Trouble Code (DTC)" . (The DTC in TCM will be erased)
3. Select Service $04 with GST (Generic Scan Tool).
No Tools
NOTE:
If the DTC is not for AT related items (see EC-8, "
INDEX FOR DTC" ), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Perform AT-37, "
OBD-II Diagnostic Trouble Code (DTC)" . (The DTC in the TCM will be erased.)
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to
EC-65, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
● If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.
● The following data are cleared when the ECM memory is erased.
– Diagnostic trouble codes
– 1st trip diagnostic trouble codes
– Freeze frame data
– 1st trip freeze frame data
– System readiness test (SRT) codes
SCIA5671E
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
– Test values
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Malfunction Indicator Lamp (MIL) UBS00KZS
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with-
out the engine running. This is a bulb check.
If the MIL does not light up, refer to DI-30, "
WARNING LAMPS" ,
or see EC-667, "
MIL AND DATA LINK CONNECTOR" .
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
SEF217U
Diagnostic Test
Mode
KEY and ENG.
Status
Function Explanation of Function
Mode I Ignition switch in
ON position
Engine stopped
BULB CHECK This function checks the MIL bulb for damage (blown,
open circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running MALFUNCTION
WARNING
This is a usual driving condition. When a malfunction is
detected twice in two consecutive driving cycles (two trip
detection logic), the MIL will light up to inform the driver
that a malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.
● Misfire (Possible three way catalyst damage)
● One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stopped
SELF-DIAGNOSTIC
RESULTS
This function allows DTCs and 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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MIL Flashing Without DTC
When any SRT codes are not set, MIL may flash without DTC. For the details, refer to EC-57, "How to Display
SRT Status" .
HOW TO SWITCH DIAGNOSTIC TEST MODE
NOTE:
● It is better to count the time accurately with a clock.
● It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
● Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.
How to Set Diagnostic Test Mode II (Self-diagnostic Results)
1. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts
blinking.
NOTE:
Do not release the accelerator pedal for 10 seconds if MIL may start blinking on the halfway of this
10 seconds. This blinking is displaying SRT status and is continued for another 10 seconds. For
the details, refer to EC-57, "
How to Display SRT Status" .
4. Fully release the accelerator pedal.
ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).
NOTE:
Wait until the same DTC (or 1st trip DTC) appears to confirm all DTCs certainly.
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to EC-65, "How to Set Diagnostic Test
Mode II (Self-diagnostic Results)" .
2. Fully depress the accelerator pedal and keep it for more than 10 seconds.
The emission-related diagnostic information has been erased from the backup memory in the ECM.
3. Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.
DIAGNOSTIC TEST MODE I — BULB CHECK
In this mode, the MIL on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to DI-
30, "WARNING LAMPS" or see EC-667, "MIL AND DATA LINK CONNECTOR" .
DIAGNOSTIC TEST MODE I — MALFUNCTION WARNING
This DTC number is clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS)
DIAGNOSTIC TEST MODE II — SELF-DIAGNOSTIC RESULTS
In this mode, the DTC and 1st trip DTC are indicated by the number of blinks of the MIL as shown below.
PBIB0092E
MIL Condition
ON When the malfunction is detected.
OFF No malfunction.
EC-66
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
The DTC and 1st trip DTC are displayed at the same time. If the MIL does not illuminate in diagnostic test
mode I (Malfunction warning), all displayed items are 1st trip DTCs. If only one code is displayed when the MIL
illuminates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are
displayed, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These uniden-
tified codes can be identified by using the CONSULT-II or GST. A DTC will be used as an example for how to
read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-8, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
65, "How to Erase Diagnostic Test Mode II (Self-diagnostic Results)" .
● If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.
● Be careful not to erase the stored memory before starting trouble diagnoses.
OBD System Operation Chart UBS00KZT
RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS
● When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.
● When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MIL will come on. For details, refer to EC-48, "
Two Trip Detection
Logic" .
● The MIL will go off after the vehicle is driven 3 times (driving pattern B) with no malfunction. The drive is
counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction
occurs while counting, the counter will reset.
● The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A)
without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and
Fuel Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times
(driving pattern C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC
RESULTS” mode of CONSULT-II will count the number of times the vehicle is driven.
● The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.
PBIA3905E
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-67
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SUMMARY CHART
For details about patterns B and C under “Fuel Injection System” and “Misfire”, see EC-69, "EXPLANATION FOR DRIVING PATTERNS
FOR “MISFIRE <EXHAUST QUALITY DETERIORATION>”, “FUEL INJECTION SYSTEM”" .
For details about patterns A and B under Other, see EC-71, "
EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE
<EXHAUST QUALITY DETERIORATION>”, “FUEL INJECTION SYSTEM”" .
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.
Items Fuel Injection System Misfire Other
MIL (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no
display)
80 (pattern C) 80 (pattern C) 40 (pattern A)
1st Trip DTC (clear)
1 (pattern C), *
1
1 (pattern C), *
1
1 (pattern B)
1st Trip Freeze Frame Data
(clear)
*1, *2 *1, *2 1 (pattern B)
EC-68
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR “MISFIRE
” <EXHAUST QUALITY DETERIORATION>, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips,
MIL will light up.
*2: MIL will go off after vehicle is driven
3 times (pattern B) without any mal-
functions.
*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 80 times (pattern C)
without the same malfunction. (The
DTC and the freeze frame data still
remain in ECM.)
*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.
*6: The 1st trip DTC and the 1st trip
freeze frame data will be cleared at
the moment OK is detected.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.
*8: 1st trip DTC will be cleared when
vehicle is driven once (pattern C)
without the same malfunction after
DTC is stored in ECM.
SEF392S
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-69
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EXPLANATION FOR DRIVING PATTERNS FOR “MISFIRE <EXHAUST QUALITY DETERIORA-
TION>”, “FUEL INJECTION SYSTEM”
<Driving Pattern B>
Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
● The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
● The B counter will be counted up when driving pattern B is satisfied without any malfunction.
● The MIL will go off when the B counter reaches 3. (*2 in “OBD SYSTEM OPERATION CHART”)
<Driving Pattern C>
Driving pattern C means the vehicle operation as follows:
The following conditions should be satisfied at the same time:
Engine speed: (Engine speed in the freeze frame data) ±375 rpm
Calculated load value: (Calculated load value in the freeze frame data) x (1±0.1) [%]
Engine coolant temperature (T) condition:
● When the freeze frame data shows lower than 70°C (158°F), T should be lower than 70°C (158°F).
● When the freeze frame data shows higher than or equal to 70°C (158°F), T should be higher than or equal
to 70°C (158°F).
Example:
If the stored freeze frame data is as follows:
Engine speed: 850 rpm, Calculated load value: 30%, Engine coolant temperature: 80°C (176°F)
To be satisfied with driving pattern C, the vehicle should run under the following conditions:
Engine speed: 475 - 1,225 rpm, Calculated load value: 27 - 33%, Engine coolant temperature: more than 70°C
(158°F)
● The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.
● The C counter will be counted up when vehicle conditions above is satisfied without the same malfunction.
● The DTC will not be displayed after C counter reaches 80.
● The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC
is stored in ECM.
EC-70
Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS EXCEPT FOR
“MISFIRE <EXHAUST QUALITY DETERIORATION>”, “FUEL INJECTION SYSTEM”
*1: When the same malfunction is
detected in two consecutive trips,
MIL will light up.
*2: MIL will go off after vehicle is driven
3 times (pattern B) without any mal-
functions.
*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 40 times (pattern A)
without the same malfunction.
(The DTC and the freeze frame data
still remain in ECM.)
*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.
*6: 1st trip DTC will be cleared after
vehicle is driven once (pattern B)
without the same malfunction.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.
SEF393SD
ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-71
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EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE <EXHAUST QUALITY
DETERIORATION>”, “FUEL INJECTION SYSTEM”
<Driving Pattern A>
● The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
● The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
● The DTC will not be displayed after the A counter reaches 40.
<Driving Pattern B>
Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
● The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
● The B counter will be counted up when driving pattern B is satisfied without any malfunctions.
● The MIL will go off when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).
AEC574
EC-72
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
BASIC SERVICE PROCEDURE PFP:00018
Basic Inspection UBS00KZU
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
– Harness connectors for improper connections
– Wiring harness for improper connections, pinches and cut
– Vacuum hoses for splits, kinks and improper connections
– Hoses and ducts for leaks
– Air cleaner clogging
– Gasket
3. Confirm that electrical or mechanical loads are not applied.
– Headlamp switch is OFF.
– Air conditioner switch is OFF.
– Rear window defogger switch is OFF.
– Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF983U
SEF976U
SEF977U
BASIC SERVICE PROCEDURE
EC-73
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Revision: October 2005 2005 QX56
3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
PBIA8513J
650 ± 50 rpm (in P or N position)
SEF058Y
650 ± 50 rpm (in P or N position)
EC-74
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
6. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Yes or No
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .
● Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
BASIC SERVICE PROCEDURE
EC-75
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10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-77, "
IGNITION TIMING" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 11.
11. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Yes or No
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15 ± 5° BTDC (in P or N position)
BBIA0379E
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
EC-76
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-77, "
IGNITION TIMING" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-35, "
TIMING CHAIN" .
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17. DETECT MALFUNCTIONING PART
Check the following.
● Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .
● Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
19. INSPECTION END
Did you replace ECM, referring this Basic Inspection procedure?
Yes or No
Yes >> 1. Perform EC-90, "VIN Registration" .
2. INSPECTION END
No >> INSPECTION END
15 ± 5° BTDC (in P or N position)
BBIA0379E
BASIC SERVICE PROCEDURE
EC-77
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Revision: October 2005 2005 QX56
Idle Speed and Ignition Timing Check UBS00KZV
IDLE SPEED
With CONSULT-II
Check idle speed in “DATA MONITOR” mode with CONSULT-II.
With GST
Check idle speed with GST.
IGNITION TIMING
Any of following two methods may be used.
Method A
1. Attach timing light to loop wire as shown.
2. Check ignition timing.
Method B
1. Remove ignition coil No.1.
SEF058Y
BBIA0377E
BBIA0379E
BBIA0360E
EC-78
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
2. Connect ignition coil No.1 and spark plug with suitable high-ten-
sion wire as shown, and attach timing light clamp to this wire.
3. Check ignition timing.
BBIA0378E
SEF011V
BBIA0379E
BASIC SERVICE PROCEDURE
EC-79
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Revision: October 2005 2005 QX56
Idle Mixture Ratio Adjustment UBS00KZW
PREPARATION
1. Make sure that the following parts are in good order.
● Battery
● Ignition system
● Engine oil and coolant levels
● Fuses
● ECM harness connector
● Vacuum hoses
● Air intake system
(Oil filler cap, oil level gauge, etc.)
● Fuel pressure
● Engine compression
● Throttle valve
● Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3. Checks should be carried out while selector lever is in P or N position.
4. When measuring CO percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn off headlamp, heater blower, rear window defogger.
6. Keep front wheels pointed straight ahead.
EC-80
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
OVERALL SEQUENCE
PBIB2086E
BASIC SERVICE PROCEDURE
EC-81
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Revision: October 2005 2005 QX56
DETAILED PROCEDURE
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
– Harness connectors for improper connections
– Wiring harness for improper connections, pinches and cut
– Vacuum hoses for splits, kinks and improper connections
– Hoses and ducts for leaks
– Air cleaner clogging
– Gasket
3. Confirm that electrical or mechanical loads are not applied.
– Head lamp switch is OFF.
– Air conditioner switch is OFF.
– Rear window defogger switch is OFF.
– Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF983U
SEF976U
SEF977U
EC-82
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) 2 or 3 times under no load,
then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) 2 or 3 times under no load, then run engine at idle speed for about 1
minute.
3. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
PBIA8513J
650 ± 50 rpm (in P or N position)
SEF058Y
650 ± 50 rpm (in P or N position)
BASIC SERVICE PROCEDURE
EC-83
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Revision: October 2005 2005 QX56
6. PERFORM IDLE AIR VOLUME LEARNING
Perform EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Yes or No
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .
● Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
650± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
EC-84
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
10. CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-77, "
IGNITION TIMING" .
OK or NG
OK (With CONSULT-II)>>GO TO 19.
OK (With GST)>>GO TO 20.
NG >> GO TO 11.
11. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 13.
13. PERFORM IDLE AIR VOLUME LEARNING
Perform EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Yes or No
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-77, "
IDLE SPEED" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-77, "
IDLE SPEED" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15 ± 5° BTDC (in P or N position)
BBIA0379E
650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
BASIC SERVICE PROCEDURE
EC-85
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15. CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-77, "
IGNITION TIMING" .
OK or NG
OK (With CONSULT-II)>>GO TO 19.
OK (Without CONSULT-II)>>GO TO 20.
NG >> GO TO 16.
16. CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-35, "
TIMING CHAIN" .
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17. DETECT MALFUNCTIONING PART
Check the following.
● Check camshaft position sensor (PHASE) and circuit. Refer to EC-291, "DTC P0340 CMP SENSOR
(PHASE)" .
● Check crankshaft position sensor (POS) and circuit. Refer to EC-284, "DTC P0335 CKP SENSOR (POS)"
.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
15 ± 5° BTDC (in P or N position)
BBIA0379E
EC-86
Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
19. CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION
With CONSULT-II
1. Turn ignition switch OFF and wait at a least 10 seconds.
2. Start engine and warm it up to normal operating temperature.
3. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in D position.
NOTE:
Keep the accelerator pedal as steady as possible during the cruising.
4. Release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
5. Repeat steps 3 to 4 for 5 times.
6. Stop the vehicle and connect CONSULT-II to the vehicle.
7. Make sure that no (1st trip) DTC is displayed in “SELF-DIAG RESULTS” mode.
OK or NG
OK >> INSPECTION END
NG >> GO TO 21.
20. CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION
With GST
1. Turn ignition switch OFF and wait at a least 10 seconds.
2. Start engine and warm it up to normal operating temperature.
3. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in D position.
NOTE:
Keep the accelerator pedal as steady as possible during the cruising.
4. Release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
5. Repeat steps 3 to 4 for 5 times.
6. Stop the vehicle and connect GST to the vehicle.
7. Make sure that no (1st trip) DTC is displayed.
OK or NG
OK >> INSPECTION END
NG >> GO TO 21.
BASIC SERVICE PROCEDURE
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21. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HARNESS
1. Turn ignition switch OFF and disconnect battery ground cable.
2. Disconnect ECM harness connector.
3. Disconnect A/F sensor 1 harness connector.
4. Check harness continuity between the following terminals.
Refer to EC-461, "
Wiring Diagram" .
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 22.
NG >> 1. Repair open circuit or short to ground or short to power in harness or connectors.
2. GO TO 4.
22. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Reconnect ECM harness connector.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
>> GO TO 23.
23. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-90, "
Throttle Valve Closed Position Learning" .
>> GO TO 24.
24. PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-91, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Yes or No
Yes (With CONSULT-II)>>GO TO 25.
Yes (Without CONSULT-II)>>GO TO 26.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
EC-88
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BASIC SERVICE PROCEDURE
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25. CHECK CO%
With CONSULT-II
1. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
2. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
3. Select “ENG COOLANT TEMP” in “ACTIVE TEST” mode.
4. Set “ENG COOLANT TEMP” to 5°C (41°F) by touching “DOWN”
and “Qd”.
5. Start engine and rev it (2,000 to 3,000 rpm) two or three times
under no load, then run engine at idle speed.
6. Check CO%.
OK or NG
OK >> GO TO 28.
NG >> GO TO 27.
26. CHECK CO%
Without CONSULT-II
1. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge.
2. Turn ignition switch OFF.
3. Disconnect engine coolant temperature sensor harness connector.
4. Connect a resistor (4.4 kΩ) between terminals of engine coolant
temperature sensor harness connector.
5. Start engine and rev it (2,000 to 3,000 rpm) two or three times
under no load, then run engine at idle speed.
6. Check CO%.
7. After checking CO%, turn ignition switch OFF, disconnect the
resistor from the terminals of engine coolant temperature sensor
harness connector, and then connect engine coolant tempera-
ture sensor harness connector to engine coolant temperature
sensor.
OK or NG
OK >> GO TO 28.
NG >> GO TO 27.
27. RECONNECT AIR FUEL RATIO (A/F) SENSOR 1 HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Reconnect A/F sensor 1 harness connector.
>> GO TO 31.
28. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
1. Stop engine.
2. Replace A/F sensor 1 on the malfunctioning bank.
With CONSULT-II>>GO TO 29.
With GST>>GO TO 30.
Idle CO: 3 − 11% and engine runs smoothly.
SEF172Y
Idle CO: 3 − 11% and engine runs smoothly.
SEF982UA
BASIC SERVICE PROCEDURE
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29. CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION
With CONSULT-II
1. Turn ignition switch OFF and wait at a least 10 seconds.
2. Start engine and warm it up to normal operating temperature.
3. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in D position.
NOTE:
Keep the accelerator pedal as steady as possible during the cruising.
4. Release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
5. Repeat steps 3 to 4 for 5 times.
6. Stop the vehicle and connect CONSULT-II to the vehicle.
7. Make sure that no (1st trip) DTC is displayed in “SELF-DIAG RESULTS” mode.
OK or NG
OK >> GO TO 4.
NG >> GO TO 31.
30. CHECK AIR FUEL RATIO (A/F) SENSOR 1 FUNCTION
With GST
1. Turn ignition switch OFF and wait at a least 10 seconds.
2. Start engine and warm it up to normal operating temperature.
3. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in D position.
NOTE:
Keep the accelerator pedal as steady as possible during the cruising.
4. Release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
5. Repeat steps 3 to 4 for 5 times.
6. Stop the vehicle and connect GST to the vehicle.
7. Make sure that no (1st trip) DTC is displayed.
OK or NG
OK >> GO TO 4.
NG >> GO TO 31.
31. DETECT MALFUNCTIONING PART
Check the following.
● Check fuel pressure regulator, and repair or replace if necessary. Refer to EC-93, "Fuel Pressure Check" .
● Check mass air flow sensor and its circuit, and repair or replace if necessary. Refer to EC-174, "DTC
P0101 MAF SENSOR" and EC-183, "DTC P0102, P0103 MAF SENSOR" .
● Check injector and its circuit, and repair or replace if necessary. Refer to EC-631, "INJECTOR CIRCUIT" .
● Check engine coolant temperature sensor and its circuit, and repair or replace if necessary. Refer to EC-
195, "DTC P0117, P0118 ECT SENSOR" and EC-208, "DTC P0125 ECT SENSOR" .
OK or NG
OK >> GO TO 33.
NG >> 1. Repair or replace.
2. GO TO 32.
EC-90
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BASIC SERVICE PROCEDURE
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32. ERASE UNNECESSARY DTC
After this inspection, unnecessary DTC might be displayed.
Erase the stored memory in ECM and TCM. Refer to EC-62, "
HOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATION" and AT-37, "OBD-II Diagnostic Trouble Code (DTC)" .
>> GO TO 4.
33. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
>> GO TO 4.
VIN Registration UBS00KZX
DESCRIPTION
VIN Registration is an operation to registering VIN in ECM. It must be performed each time ECM is replaced.
NOTE:
Accurate VIN which is registered in ECM may be required for Inspection & Maintenance (I/M).
OPERATION PROCEDURE
With CONSULT-II
1. Check the VIN of the vehicle and note it. Refer to GI-46, "IDENTIFICATION INFORMATION" .
2. Turn ignition switch ON and engine stopped.
3. Select “VIN REGISTRATION” in “WORK SUPPORT” mode.
4. Follow the instruction of CONSULT-II display.
Accelerator Pedal Released Position Learning UBS00KZY
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position Learning UBS00KZZ
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
PBIB2242E
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OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume Learning UBS00L00
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
● Each time electric throttle control actuator or ECM is replaced.
● Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
● Battery voltage: More than 12.9V (At idle)
● Engine coolant temperature: 70 - 100°C (158 - 212°F)
● Park/Neutral position (PNP) switch: ON
● Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is start the headlamp will not be illuminated.
● Steering wheel: Neutral (Straight-ahead position)
● Vehicle speed: Stopped
● Transmission: Warmed-up
For models with CONSULT-II, drive vehicle until “ATF TEMP SE 1” in “DATA MONITOR” mode of “A/T”
system indicates less than 0.9V.
For models without CONSULT-II, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-90, "Accelerator Pedal Released Position Learning" .
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
SEF217Z
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BASIC SERVICE PROCEDURE
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6. Touch “START” and wait 20 seconds.
7. Make sure that “CMPLT” is displayed on CONSULT-II screen. If
“CMPLT” is not displayed, Idle Air Volume Learning will not be
carried out successfully. In this case, find the cause of the inci-
dent by referring to the DIAGNOSTIC PROCEDURE below.
8. Rev up the engine two or three times and make sure that idle
speed and ignition timing are within the specifications.
Without CONSULT-II
NOTE:
● It is better to count the time accurately with a clock.
● It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit
has a malfunction.
1. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the
specifications.
SEF454Y
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
MBIB0238E
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13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried
out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1. Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttle valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5. If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:
● Engine stalls.
● Erroneous idle.
Fuel Pressure Check UBS00L01
FUEL PRESSURE RELEASE
With CONSULT-II
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
Without CONSULT-II
1. Remove fuel pump fuse located in IPDM E/R.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
SEF214Y
BBIA0380E
EC-94
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BASIC SERVICE PROCEDURE
2005 QX56
FUEL PRESSURE CHECK
CAUTION:
● Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
● Be careful not to scratch or get the fuel hose connection area dirty when servicing, so that the
quick connector o-ring maintains sealability.
● Use Fuel Pressure Gauge Kit J-44321 and Fuel Pressure Adapter J-44321-6 to check fuel pressure.
● Do not perform fuel pressure check with electrical system operating (i.e. lights, rear defog, A/C,
etc.). Fuel pressure gauge may indicate false readings due to varying engine loads and changes in
manifold vacuum.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because JA60 models do not have fuel return system.
1. Release fuel pressure to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
2. Remove engine cover.
3. Remove fuel hose using Quick Connector Release J-45488. Refer to EM-15, "
INTAKE MANIFOLD" .
● Do not twist or kink fuel hose because it is plastic hose.
● Do not remove fuel hose from quick connector.
● Keep fuel hose connections clean.
4. Install Fuel Pressure Adapter J-44321-6 and Fuel Pressure
Gauge (from kit J-44321) as shown in figure.
● Do not distort or bend fuel rail tube when installing fuel pres-
sure gauge adapter.
● When reconnecting fuel hose, check the original fuel hose for
damage and abnormality.
5. Turn ignition switch ON (reactivate fuel pump), and check for
fuel leakage.
6. Start engine and check for fuel leakage.
7. Read the indication of fuel pressure gauge.
● During fuel pressure check, check for fuel leakage from fuel
connection every 3 minutes.
8. If result is unsatisfactory, go to next step.
9. Check the following.
● Fuel hoses and fuel tubes for clogging
● Fuel filter for clogging
● Fuel pump
● Fuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.
10. Before disconnecting Fuel Pressure Gauge and Fuel Pressure Adapter J-44321-6, release fuel pressure
to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
At idling:
Approximately 350 kPa (3.57 kg/cm
2
, 51 psi)
BBIA0390E
TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSIS PFP:00004
Trouble Diagnosis Introduction UBS00L02
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-96, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on EC-100, "
Worksheet Sample" should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G
EC-96
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TROUBLE DIAGNOSIS
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WORK FLOW
Overall Sequence
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Detailed Flow
1. GET INFORMATION FOR SYMPTOM
Get the detailed information from the customer about the symptom (the condition and the environment when
the incident/malfunction occurred) using the EC-100, "
Worksheet Sample" .
>> GO TO 2.
2. CHECK DTC*
1
1. Check DTC*
1
.
2. Perform the following procedure if DTC*
1
is displayed.
– Record DTC*
1
and freeze frame data*
2
. (Print them out with CONSULT-II or GST.)
– Erase DTC*
1
. (Refer to EC-62, "HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION"
.)
– Study the relationship between the cause detected by DTC*
1
and the symptom described by the cus-
tomer. (Symptom Matrix Chart is useful. Refer to EC-104, "
Symptom Matrix Chart" .)
3. Check related service bulletins for information.
Is any symptom described and any DTC detected?
Symptom is described, DTC*
1
is displayed>>GO TO 3.
Symptom is described, DTC*
1
is not displayed>>GO TO 4.
Symptom is not described, DTC*
1
is displayed>>GO TO 5.
3. CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer (except MIL ON).
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-II to the vehicle in “DATA MONITOR (AUTO TRIG)” mode and check real time diagnosis
results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 5.
4. CONFIRM THE SYMPTOM
Try to confirm the symptom described by the customer.
DIAGNOSIS WORK SHEET is useful to verify the incident.
Connect CONSULT-II to the vehicle in “DATA MONITOR (AUTO TRIG)” mode and check real time diagnosis
results.
Verify relation between the symptom and the condition when the symptom is detected.
>> GO TO 6.
EC-98
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TROUBLE DIAGNOSIS
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5. PERFORM DTC CONFIRMATION PROCEDURE
Perform DTC Confirmation Procedure for the displayed DTC*
1
, and then make sure that DTC*
1
is detected
again.
At this time, always connect CONSULT-II to the vehicle, and check diagnostic results in real time on “DATA
MONITOR (AUTO TRIG)”.
If two or more DTCs*
1
are detected, refer to EC-101, "DTC Inspection Priority Chart" and determine trouble
diagnosis order.
NOTE:
● Freeze frame data*
2
is useful if the DTC*
1
is not detected.
● Perform Overall Function Check if DTC Confirmation Procedure is not included on Service Manual. This
simplified check procedure is an effective alternative though DTC*
1
cannot be detected during this check.
If the result of Overall Function Check is NG, it is the same as the detection of DTC*
1
by DTC Confirma-
tion Procedure.
Is DTC*
1
detected?
Yes >> GO TO 10.
No >> Check according to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
6. PERFORM BASIC INSPECTION
Perform EC-72, "
Basic Inspection" .
With CONSULT-II>>GO TO 7.
Without CONSULT-II>>GO TO 9.
7. PERFORM DATA MONITOR (SPEC) MODE
With CONSULT-II
Make sure that “MAS A/F SE-B1”, “B/FUEL SCHDL”, and “A/F
ALPHA-B1”, “A/F ALPHA-B2” are within the SP value using CON-
SULT-II “DATA MONITOR (SPEC)” mode. Refer to EC-146, "
TROU-
BLE DIAGNOSIS - SPECIFICATION VALUE" .
Are they within the SP value?
Yes >> GO TO 9.
No >> GO TO 8.
8. DETECT MALFUNCTIONING PART BY TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Detect malfunctioning part according to EC-147, "
Diagnostic Procedure" .
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> GO TO 9.
9. DETECT MALFUNCTIONING SYSTEM BY SYMPTOM MATRIX CHART
Detect malfunctioning system according to EC-104, "
Symptom Matrix Chart" based on the confirmed symp-
tom in step 4, and determine the trouble diagnosis order based on possible causes and symptom.
>> GO TO 10.
SEF601Z
TROUBLE DIAGNOSIS
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10. DETECT MALFUNCTIONING PART BY DIAGNOSTIC PROCEDURE
Inspect according to Diagnostic Procedure of the system.
NOTE:
The Diagnostic Procedure in EC section described based on open circuit inspection. A short circuit inspection
is also required for the circuit check in the Diagnostic Procedure. For details, refer to Circuit Inspection in GI-
27, "How to Perform Efficient Diagnosis for an Electrical Incident" .
Is malfunctioning part detected?
Yes >> GO TO 11.
No >> Monitor input data from related sensors or check voltage of related ECM terminals using CON-
SULT-II. Refer to EC-117, "
ECM Terminals and Reference Value" , EC-141, "CONSULT-II Refer-
ence Value in Data Monitor" .
11. REPAIR OR REPLACE THE MALFUNCTIONING PART
1. Repair or replace the malfunctioning part.
2. Reconnect parts or connectors disconnected during Diagnostic Procedure again after repair and replace-
ment.
3. Check DTC. If DTC is displayed, erase it, refer to EC-62, "
HOW TO ERASE EMISSION-RELATED DIAG-
NOSTIC INFORMATION" .
>> GO TO 12.
12. FINAL CHECK
When DTC was detected in step 2, perform DTC Confirmation Procedure or Overall Function Check again,
and then make sure that the malfunction have been repaired securely.
When symptom was described from the customer, refer to confirmed symptom in step 3 or 4, and make sure
that the symptom is not detected.
OK or NG
NG (DTC*
1
is detected)>>GO TO 10.
NG (Symptom remains)>>GO TO 6.
OK >> 1. Before returning the vehicle to the customer, make sure to erase unnecessary DTC*
1
in ECM
and TCM (Transmission Control Module). (Refer to EC-62, "
HOW TO ERASE EMISSION-
RELATED DIAGNOSTIC INFORMATION" and AT-37, "OBD-II Diagnostic Trouble Code
(DTC)" .)
2. If the completion of SRT is needed, drive vehicle under the specific driving pattern. Refer to EC-
59, "Driving Pattern" .
3. INSPECTION END
*1: Include 1st trip DTC.
*2: Include 1st trip freeze frame data.
DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MIL to come on steady or blink and
DTC to be detected. Examples:
● Vehicle ran out of fuel, which caused the engine to misfire.
● Fuel filler cap was left off or incorrectly screwed on, allowing fuel
to evaporate into the atmosphere.
SEF907L
EC-100
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TROUBLE DIAGNOSIS
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Worksheet Sample
MTBL0017
TROUBLE DIAGNOSIS
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DTC Inspection Priority Chart UBS00L03
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 and/or U1001 is displayed with other DTC, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Priority Detected items (DTC)
1
● U1000 U1001 CAN communication line
● P0101 P0102 P0103 Mass air flow sensor
● P0112 P0113 P0127 Intake air temperature sensor
● P0117 P0118 P0125 Engine coolant temperature sensor
● P0122 P0123 P0222 P0223 P1225 P1226 P2135 Throttle position sensor
● P0128 Thermostat function
● P0181 P0182 P0183 Fuel tank temperature sensor
● P0327 P0328 P0332 P0333 Knock sensor
● P0335 Crankshaft position sensor (POS)
● P0340 Camshaft position sensor (PHASE)
● P0460 P0461 P0462 P0463 Fuel level sensor
● P0500 Vehicle speed sensor
● P0605 ECM
● P0705 Park/Neutral position (PNP) switch
● P1229 Sensor power supply
● P1610 - P1615 NATS
● P1706 Park/Neutral position (PNP) switch
● P2122 P2123 P2127 P2128 P2138 Accelerator pedal position sensor
EC-102
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
2 ● P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
● P0138 P0139 P0158 P0159 P1146 P1147 P1166 P1167 Heated oxygen sensor 2
● P0441 EVAP control system purge flow monitoring
● P0444 P0445 P1444 EVAP canister purge volume control solenoid valve
● P0447 P1446 EVAP canister vent control valve
● P0451 P0452 P0453 EVAP control system pressure sensor
● P0550 Power steering pressure sensor
● P0700 P0710 P0720 P0740 P0744 P0745 P1716 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769
P1772 P1774 A/T related sensors and solenoid valves
● P1031 P1032 P1051 P1052 A/F sensor 1 heater
● P1065 ECM power supply
● P1122 Electric throttle control function
● P1124 P1126 P1128 Electric throttle control actuator
● P1217 Engine over temperature (OVERHEAT)
● P1271 P1272 P1273 P1274 P1276 P1278 P1279 P1281 P1282 P1283 P1284 P1286 P1288 P1289 A/F sensor 1
● P1805 Brake switch
3
● P0171 P0172 P0174 P0175 Fuel injection system function
● P0300 - P0308 Misfire
● P0420 P0430 Three way catalyst function
● P0442 P0455 P0456 EVAP control system
● P0506 P0507 Idle speed control system
● P1121 Electric throttle control actuator
● P1148 P1168 Closed loop control
● P1211 TCS control unit
● P1212 TCS communication line
● P1564 ICC/ASCD steering switch
● P1568 ICC command value
● P1572 ICC/ASCD brake switch
● P1574 ICC/ASCD vehicle speed sensor
Priority Detected items (DTC)
TROUBLE DIAGNOSIS
EC-103
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Revision: October 2005 2005 QX56
Fail-safe Chart UBS00L04
When the DTC listed below is detected, the ECM enters fail-safe mode and the MIL lights up.
● When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when
there is malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands
the driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103
Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118
Engine coolant tempera-
ture sensor circuit
Engine coolant temperature will be determined by ECM based on the time after turning
ignition switch ON or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition
Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned
ON or START
40°C (104°F)
More than approx. 4 minutes after
ignition ON or START
80°C (176°F)
Except as shown above
40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135
Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P1121 Electric throttle control
actuator
(When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops,
the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P1122 Electric throttle control
function
ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1124
P1126
Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1128 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P1229 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2122
P2123
P2127
P2128
P2138
Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut
EC-104
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Symptom Matrix Chart UBS00L05
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 1 1 2 3 2 2 2 3 2 EC-637
Fuel pressure regulator system 3 3 4 4 4 4 4 4 4 4 EC-94
Injector circuit 1 1 2 3 2 2 2 2 EC-631
Evaporative emission system 3 3 4 4 4 4 4 4 4 4 EC-32
Air Positive crankcase ventilation sys-
tem
33
4444444 41 EC-45
Incorrect idle speed adjustment 1 1 1 1 1 EC-72
Electric throttle control actuator 1 1 2 3 3 2 2 2 2 2 2
EC-397
,
EC-399
,
EC-405
,
EC-410
Ignition Incorrect ignition timing adjustment 3 3 1 1 1 1 1 1 EC-72
Ignition circuit 1 1 2 2 2 2 2 2 EC-619
Main power supply and ground circuit 2 2 3 3 3 3 3 2 3 EC-157
Mass air flow sensor circuit
1
12
2
222 2
EC-174
,
EC-183
Engine coolant temperature sensor circuit
3
33
EC-195
,
EC-208
Air fuel ratio (A/F) sensor 1 circuit
EC-459
,
EC-468
,
EC-477
,
EC-487
,
EC-497
,
EC-507
,
EC-519
Throttle position sensor circuit
22
EC-201
,
EC-264
,
EC-450
,
EC-452
,
EC-604
Accelerator pedal position sensor circuit 3 2 1
EC-454
,
EC-591
,
EC-597
,
EC-611
Knock sensor circuit 2 3 EC-279
Crankshaft position sensor (POS) circuit 2 2 EC-284
TROUBLE DIAGNOSIS
EC-105
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Revision: October 2005 2005 QX56
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
Camshaft position sensor (PHASE) circuit 3 2 EC-291
Vehicle speed signal circuit 2 3 3 3 EC-372
Power steering pressure sensor circuit 2 3 3 EC-378
ECM 22333333333
EC-383
,
EC-393
Park/Neutral position (PNP) switch circuit 3 3 3 3 3 EC-581
Refrigerant pressure sensor circuit 2 3 3 4 EC-643
Electrical load signal circuit 3 EC-648
Air conditioner circuit 2 2 3 3 3 3 3 3 3 3 2 ATC-33
ABS actuator and electric unit (control unit) 4
EC-438
,
EC-439
or BRC-11
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
EC-106
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
SYSTEM — ENGINE MECHANICAL & OTHER
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank
5
5
FL-9
Fuel piping 5 5 5 5 5 5 FL-3
Vapor lock —
Valve deposit
555555 5
—
Poor fuel (Heavy weight gaso-
line, Low octane)
—
Air Air duct
55555 5
EM-14
Air cleaner EM-14
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555
EM-14
Electric throttle control actuator EM-15
Air leakage from intake manifold/
Collector/Gasket
EM-15
Cranking Battery
111111
1
1
SC-4
Generator circuit SC-17
Starter circuit 3 SC-10
Signal plate 6 EM-35
Park/Neutral position (PNP)
switch
4 AT-104
Engine Cylinder head
55555 55 5 EM-58
Cylinder head gasket 4 3
Cylinder block
66666 66 6
4
EM-73
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Valve
mecha-
nism
Timing chain
55555 55 5
EM-35
Camshaft EM-43
Intake valve
3 EM-58
Exhaust valve
TROUBLE DIAGNOSIS
EC-107
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Revision: October 2005 2005 QX56
1 - 6: The numbers refer to the order of inspection.
Exhaust Exhaust manifold/Tube/Muffler/
Gasket
55555 55 5
EM-19, EX-
3
Three way catalyst
Lubrica-
tion
Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5
EM-22
, LU-
13 , LU-10 ,
LU-11
Oil level (Low)/Filthy oil LU-7
Cooling Radiator/Hose/Radiator filler cap
55555 55 45
CO-12
Thermostat 5 CO-19
Water pump CO-17
Water gallery CO-8
Cooling fan 5 CO-15
Coolant level (Low)/Contami-
nated coolant
5 CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS)
11 BL-137
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
EC-108
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Engine Control Component Parts Location UBS00L06
BBIA0449E
TROUBLE DIAGNOSIS
EC-109
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Revision: October 2005 2005 QX56
BBIA0447E
EC-110
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
BBIA0382E
TROUBLE DIAGNOSIS
EC-111
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EC
Revision: October 2005 2005 QX56
BBIA0448E
EC-112
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
BBIA0384E
TROUBLE DIAGNOSIS
EC-113
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EC
Revision: October 2005 2005 QX56
PBIB2639E
TROUBLE DIAGNOSIS
EC-115
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Revision: October 2005 2005 QX56
Circuit Diagram UBS00L08
BBWA1788E
EC-116
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
BBWA1789E
TROUBLE DIAGNOSIS
EC-117
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Revision: October 2005 2005 QX56
ECM Harness Connector Terminal Layout UBS00L09
ECM Terminals and Reference Value UBS00L0A
PREPARATION
1. ECM is located in the engine room passenger side behind bat-
tery.
2. Remove ECM harness connector.
3. When disconnecting ECM harness connector, loosen it with
levers as far as they will go as shown in the figure.
4. Connect a break-out box (SST) and Y-cable adapter (SST)
between the ECM and ECM harness connector.
● Use extreme care not to touch 2 pins at one time.
● Data is for comparison and may not be exact.
ECM INSPECTION TABLE
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECMs transistor. Use a ground other than ECM terminals, such as the ground.
MBIB0045E
BBIA0386E
BBIA0387E
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
1 B ECM ground
[Engine is running]
● Idle speed
Body ground
2O/B
A/F sensor 1 heater
(bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 5V
PBIB1584E
EC-118
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3L
Throttle control motor relay
power supply
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
0 - 14V
5 L/B Throttle control motor (Open)
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
0 - 14V
6GR
Heated oxygen sensor 2
heater (bank 1)
[Engine is running]
● Warm-up condition
● Engine speed is below 3,600 rpm after the
following conditions are met.
– Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
[Engine is running]
● Engine speed: Above 3,600 rpm
BATTERY VOLTAGE
(11 - 14V)
12 R
Power steering pressure sen-
sor
[Engine is running]
● Steering wheel: Being turned
0.5 - 4.5V
[Engine is running]
● Steering wheel: Not being turned
0.4 - 0.8V
13 O
Crankshaft position sensor
(POS)
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle
Approximately 10V
[Engine is running]
● Engine speed: 2,000 rpm
Approximately 10V
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E
TROUBLE DIAGNOSIS
EC-119
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Revision: October 2005 2005 QX56
14 Y
Camshaft position sensor
(PHASE)
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle
1.0 - 4.0V
[Engine is running]
● Engine speed: 2,000 rpm
1.0 - 4.0V
15 W Knock sensor (bank 1)
[Engine is running]
● Idle speed
Approximately 2.5V
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
21
22
23
44
O/L
BR
GR/W
O
Injector No. 5
Injector No. 3
Injector No. 1
Injector No. 7
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
● Warm-up condition
● Engine speed: 2,000 rpm
BATTERY VOLTAGE
(11 - 14V)
24 BR/W
A/F sensor 1 heater
(bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 5V
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
PBIB1039E
PBIB1040E
SEC984C
SEC985C
PBIB1584E
EC-120
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
25 O/G
Heated oxygen sensor 2
heater (bank 2)
[Engine is running]
● Warm-up condition
● Engine speed is below 3,600 rpm after the
following conditions are met.
– Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load
0 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
[Engine is running]
● Engine speed: Above 3,600 rpm
BATTERY VOLTAGE
(11 - 14V)
32 L
EVAP control system pres-
sure sensor
[Ignition switch: ON] Approximately 1.8 - 4.8V
34 R/B Intake air temperature sensor [Engine is running]
Approximately 0 - 4.8V
Output voltage varies with intake
air temperature.
36 W Knock sensor (bank 2)
[Engine is running]
● Idle speed
Approximately 2.5V
40
41
42
63
Y/G
P
L
G
Injector No. 6
Injector No. 4
Injector No. 2
Injector No. 8
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
● Warm-up condition
● Engine speed: 2,000 rpm
BATTERY VOLTAGE
(11 - 14V)
45 L/Y
EVAP canister purge volume
control solenoid valve
[Engine is running]
● Idle speed
● Accelerator pedal: Not depressed even
slightly, after engine starting
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
● Engine speed: About 2,000 rpm (More than
100 seconds after starting engine)
BATTERY VOLTAGE
(11 - 14V)
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
SEC984C
SEC985C
SEC990C
SEC991C
TROUBLE DIAGNOSIS
EC-121
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Revision: October 2005 2005 QX56
47 Y
Sensor power supply
(Throttle position sensor)
[Ignition switch: ON] Approximately 5V
48 SB
Sensor power supply
(EVAP control system pres-
sure sensor)
[Ignition switch: ON] Approximately 5V
49 R/Y
Sensor power supply
(Refrigerant pressure sensor)
[Ignition switch: ON] Approximately 5V
50 B Throttle position sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
Less than 4.75V
51 W Mass air flow sensor
[Engine is running]
● Warm-up condition
● Idle speed
1.0 - 1.3V
[Engine is running]
● Warm-up condition
● Engine speed: 2,500 rpm
1.7 - 2.1V
55 R
Heated oxygen sensor 2
(bank 1)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met.
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at
idle for 1 minute under no load
0 - Approximately 1.0V
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
46
60
61
62
L/R
GR/R
O/W
Y/R
Ignition signal No. 7
Ignition signal No. 5
Ignition signal No. 3
Ignition signal No. 1
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle
0 - 0.3V
[Engine is running]
● Warm-up condition
● Engine speed: 2,500 rpm
0.1 - 0.6V
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
SEC986C
SEC987C
EC-122
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
66 R
Sensor ground
(Throttle position sensor)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
68 W/L
Sensor power supply
(PSP sensor)
[Ignition switch: ON] Approximately 5V
69 W Throttle position sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
More than 0.36V
70 B/W Refrigerant pressure sensor
[Engine is running]
● Warm-up condition
● Both A/C switch and blower switch: ON
(Compressor operates.)
1.0 - 4.0V
73 Y/B
Engine coolant temperature
sensor
[Engine is running]
Approximately 0 - 4.8V
Output voltage varies with
engine coolant temperature.
74 L
Heated oxygen sensor 2
(bank 2)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are
met.
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at
idle for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
65
79
80
81
G/R
V/W
W/R
W/G
Ignition signal No. 8
Ignition signal No. 6
Ignition signal No. 4
Ignition signal No. 2
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle
0 - 0.3V
[Engine is running]
● Warm-up condition
● Engine speed: 2,500 rpm
0.1 - 0.6V
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
SEC986C
SEC987C
TROUBLE DIAGNOSIS
EC-123
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Revision: October 2005 2005 QX56
82 B/R
Sensor ground
(APP sensor 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
83 G/W
Sensor ground
(APP sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
85 G/W Data link connector
[Ignition switch: ON]
● CONSULT-II or GST: Disconnected
Approximately 5V - Battery volt-
age (11 - 14V)
86 P CAN communication line [Ignition switch: ON]
Approximately 1.1 - 2.3V
Output voltage varies with the
communication status
90 L
Sensor power supply
(APP sensor 1)
[Ignition switch: ON] Approximately 5V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
94 L CAN communication line [Ignition switch: ON]
Approximately 2.6 - 3.2V
Output voltage varies with the
communication status.
98 G/R
Accelerator pedal position
sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.25 - 0.50V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
2.0 - 2.5V
99 G/Y
ASCD steering switch
(Models with ICC system)
[Ignition switch: ON]
● ICC steering switch: OFF
Approximately 4.3V
[Ignition switch: ON]
● MAIN switch: Pressed
Approximately 0V
[Ignition switch: ON]
● CANCEL switch: Pressed
Approximately 1.3V
[Ignition switch: ON]
● RESUME/ACCELERATE switch: Pressed
Approximately 3.7V
[Ignition switch: ON]
● SET/COAST switch: Pressed
Approximately 3V
[Ignition switch: ON]
● DISTANCE switch: Pressed
Approximately 2.2V
99 G/Y
ASCD steering switch
(Models with ASCD system)
[Ignition switch: ON]
● ASCD steering switch: OFF
Approximately 4V
[Ignition switch: ON]
● MAIN switch: Pressed
Approximately 0V
[Ignition switch: ON]
● CANCEL switch: Pressed
Approximately 1V
[Ignition switch: ON]
● RESUME/ACCELERATE switch: Pressed
Approximately 3V
[Ignition switch: ON]
● SET/COAST switch: Pressed
Approximately 2V
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
EC-124
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TROUBLE DIAGNOSIS
2005 QX56
101 R/W Stop lamp switch
[Ignition switch: OFF]
● Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
● Brake pedal: Slightly depressed
BATTERY VOLTAGE
(11 - 14V)
102 GR/R PNP switch
[Ignition switch: ON]
● Selector lever: P or N
Approximately 0V
[Ignition switch: ON]
● Except the above gear position
BATTERY VOLTAGE
(11 - 14V)
104 O Throttle control motor relay
[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
106 BR/W
Accelerator pedal position
sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
4.2 - 4.8V
107 V/R Fuel tank temperature sensor [Engine is running]
Approximately 0 - 4.8V
Output voltage varies with fuel
tank temperature.
108 BR/W
ICC brake switch
(Models with ICC system)
ASCD brake switch
(Models with ASCD system)
[Ignition switch: ON]
● Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
● Brake pedal: Fully released
BATTERY VOLTAGE
(11 - 14V)
109 L/W Ignition switch
[Ignition switch: OFF] 0V
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
113 GR Fuel pump relay
[Ignition switch: ON]
● For 1 second after turning ignition switch
ON
[Engine is running]
0 - 1.5V
[Ignition switch: ON]
● More than 1 second after turning ignition
switch ON
BATTERY VOLTAGE
(11 - 14V)
115
116
B
B/W
ECM ground
[Engine is running]
● Idle speed
Body ground
117 L/Y
EVAP canister vent control
valve
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
121 W
Power supply for ECM
(Back-up)
[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
TROUBLE DIAGNOSIS
EC-125
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
EC-126
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
CONSULT-II Function (ENGINE) UBS00L0B
FUNCTION
*: The following emission-related diagnostic information is cleared when the ECM memory is erased.
● Diagnostic trouble codes
● 1st trip diagnostic trouble codes
● Freeze frame data
● 1st trip freeze frame data
● System readiness test (SRT) codes
● Test values
Diagnostic test mode Function
Work support
This mode enables a technician to adjust some devices faster and more accurately by following the
indications on the CONSULT-II unit.
Self-diagnostic results
Self-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data
can be read and erased quickly.*
Data monitor Input/Output data in the ECM can be read.
Data monitor (SPEC)
Input/Output of the specification for Basic fuel schedule, AFM, A/F feedback control value and the
other data monitor items can be read.
CAN diagnostic support
monitor
The results of transmit/receive diagnosis of CAN communication can be read.
Active test
Diagnostic Test Mode in which CONSULT-II drives some actuators apart from the ECMs and also
shifts some parameters in a specified range.
DTC & SRT confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
Function test This mode is used to inform customers when their vehicle condition requires periodic maintenance.
ECM part number ECM part number can be read.
TROUBLE DIAGNOSIS
EC-127
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ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
Item
DIAGNOSTIC TEST MODE
WORK
SUP-
PORT
SELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TOR
DATA
MONI-
TOR
(SPEC)
ACTIVE
TEST
DTC & SRT
CONFIRMATION
DTC*1
FREEZE
FRAME
DATA*2
SRT
STATUS
DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ××××
Camshaft position sensor (PHASE) ××××
Mass air flow sensor ×××
Engine coolant temperature sensor ×××××
Air fuel ratio (A/F) sensor 1 ×××××
Heated oxygen sensor 2 ×××××
Wheel sensor ××××
Accelerator pedal position sensor ×××
Throttle position sensor ××××
Fuel tank temperature sensor ××××
EVAP control system pressure
sensor
×××
Intake air temperature sensor ××××
Knock sensor ×
Refrigerant pressure sensor ××
Closed throttle position switch
(accelerator pedal position sensor
signal)
××
Air conditioner switch ××
Park/neutral position (PNP) switch ×××
Stop lamp switch ×××
Power steering pressure sensor ×××
Battery voltage ××
Load signal ××
Fuel level sensor ×××
ICC steering switch ×××
ASCD steering switch ×××
ICC brake switch ×××
ASCD brake switch ×××
EC-128
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-130, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
INSPECTION PROCEDURE
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication.
1. Turn ignition switch OFF.
2. Connect “CONSULT-II” and “CONSULT-II CONVERTER” to
data link connector, which is located under LH dash panel near
the hood opener handle.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL)”.
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector ×× ×
Power transistor (Ignition timing) ×× ×
Throttle control motor relay ×××
Throttle control motor ×
EVAP canister purge volume con-
trol solenoid valve
×××××
Air conditioner relay ××
Fuel pump relay ××××
Cooling fan relay ××××
Air fuel ratio (A/F) sensor 1 heater ××××
Heated oxygen sensor 2 heater ××××
EVAP canister vent control valve ×× ×××
Calculated load value ×××
Item
DIAGNOSTIC TEST MODE
WORK
SUP-
PORT
SELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TOR
DATA
MONI-
TOR
(SPEC)
ACTIVE
TEST
DTC & SRT
CONFIRMATION
DTC*1
FREEZE
FRAME
DATA*2
SRT
STATUS
DTC
WORK
SUP-
PORT
BBIA0369E
BCIA0029E
TROUBLE DIAGNOSIS
EC-129
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5. Touch “ENGINE”.
If “ENGINE” is not indicated, go to GI-39, "
CONSULT-II Data
Link Connector (DLC) Circuit" .
6. Perform each diagnostic test mode according to each service
procedure.
For further information, see the CONSULT-II Operation Manual.
WORK SUPPORT MODE
Work Item
BCIA0030E
BCIA0031E
WORK ITEM CONDITION USAGE
FUEL PRESSURE RELEASE
● FUEL PUMP WILL STOP BY TOUCHING “START” DUR-
ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.
When releasing fuel pressure
from fuel line
IDLE AIR VOL LEARN
● THE IDLE AIR VOLUME THAT KEEPS THE ENGINE
WITHIN THE SPECIFIED RANGE IS MEMORIZED IN
ECM.
When learning the idle air volume
SELF-LEARNING CONT
● THE COEFFICIENT OF SELF-LEARNING CONTROL
MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT.
When clearing the coefficient of
self-learning control value
EVAP SYSTEM CLOSE CLOSE THE EVAP CANISTER VENT CONTROL VALVE IN
ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE
FOLLOWING CONDITIONS.
● IGN SW ON
● ENGINE NOT RUNNING
● AMBIENT TEMPERATURE IS ABOVE 0°C (32°F).
● NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS-
TEM
● FUEL TANK TEMP. IS MORE THAN 0°C (32°F).
● WITHIN 10 MINUTES AFTER STARTING “EVAP SYS-
TEM CLOSE”
● WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE”
UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
II WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-II MAY DISPLAY
“BATTERY VOLTAGE IS LOW. CHARGE BATTERY”,
EVEN IN USING CHARGED BATTERY.
When detecting EVAP vapor leak
point of EVAP system
VIN REGISTRATION
● IN THIS MODE, VIN IS REGISTERED IN ECM When registering VIN in ECM
EC-130
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
*: This function is not necessary in the usual service procedure.
SELF-DIAG RESULTS MODE
Self Diagnostic Item
Regarding items of “DTC and 1st trip DTC”, refer to EC-49, "EMISSION-RELATED DIAGNOSTIC INFORMA-
TION ITEMS" .
Freeze Frame Data and 1st Trip Freeze Frame Data
*: The item is the same as that of 1st trip freeze frame data.
TARGET IDLE RPM ADJ*
● IDLE CONDITION When setting target idle speed
TARGET IGN TIM ADJ*
● IDLE CONDITION When adjusting target ignition tim-
ing
WORK ITEM CONDITION USAGE
Freeze frame data
item*
Description
DIAG TROUBLE
CODE
[PXXXX]
● The engine control component part/control system has a trouble code, it is displayed as “PXXXX”. (Refer
to EC-8, "
INDEX FOR DTC" .)
FUEL SYS-B1
● “Fuel injection system status” at the moment a malfunction is detected is displayed.
● One mode in the following is displayed.
“Mode2”: Open loop due to detected system malfunction
“Mode3”: Open loop due to driving conditions (power enrichment, deceleration enleanment)
“Mode4”: Closed loop - using oxygen sensor(s) as feedback for fuel control
“Mode5”: Open loop - has not yet satisfied condition to go to closed loop
FUEL SYS-B2
CAL/LD VALUE [%]
● The calculated load value at the moment a malfunction is detected is displayed.
COOLANT TEMP
[°C] or [°F]
● The engine coolant temperature at the moment a malfunction is detected is displayed.
L-FUEL TRM-B1 [%]
● “Long-term fuel trim” at the moment a malfunction is detected is displayed.
● The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule
than short-term fuel trim.
L-FUEL TRM-B2 [%]
S-FUEL TRM-B1 [%]
● “Short-term fuel trim” at the moment a malfunction is detected is displayed.
● The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel
schedule.
S-FUEL TRM-B2 [%]
ENGINE SPEED
[rpm]
● The engine speed at the moment a malfunction is detected is displayed.
VEHICL SPEED
[km/h] or [mph]
● The vehicle speed at the moment a malfunction is detected is displayed.
ABSOL TH-P/S
[%]
● The throttle valve opening at the moment a malfunction is detected is displayed.
B/FUEL SCHDL
[msec]
● The base fuel schedule at the moment a malfunction is detected is displayed.
INT/A TEMP SE
[°C] or [°F]
● The intake air temperature at the moment a malfunction is detected is displayed.
TROUBLE DIAGNOSIS
EC-131
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DATA MONITOR MODE
Monitored Item
×: Applicable
Monitored item
[Unit]
ECM
INPUT
SIGNALS
MAIN
SIGNALS
Description Remarks
ENG SPEED [rpm] ××
● Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE).
● Accuracy becomes poor if engine
speed drops below the idle rpm.
● If the signal is interrupted while the
engine is running, an abnormal value
may be indicated.
MAS A/F SE-B1 [V] ××
● The signal voltage of the mass air flow
sensor is displayed.
● When the engine is stopped, a certain
value is indicated.
B/FUEL SCHDL
[msec]
×
● Base fuel schedule indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
A/F ALPHA-B1 [%] ×
● The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
● When the engine is stopped, a certain
value is indicated.
● This data also includes the data for the
air-fuel ratio learning control.
A/F ALPHA-B2 [%] ×
COOLAN TEMP/S
[°C] or [°F]
××
● The engine coolant temperature (deter-
mined by the signal voltage of the
engine coolant temperature sensor) is
displayed.
● When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine
coolant temperature determined by the
ECM is displayed.
A/F SEN1 (B1) [V] ××
● The A/F signal computed from the input
signal of the A/F sensor 1 is displayed.
A/F SEN1 (B2) [V] ×
HO2S2 (B1) [V] ×
● The signal voltage of the heated oxygen
sensor 2 is displayed.
HO2S2 (B2) [V] ×
HO2S2 MNTR (B1)
[RICH/LEAN]
×
● Display of heated oxygen sensor 2 sig-
nal:
RICH: means the amount of oxygen
after three way catalyst is relatively
small.
LEAN: means the amount of oxygen
after three way catalyst is relatively
large.
● When the engine is stopped, a certain
value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN]
×
VHCL SPEED SE
[km/h] or [mph]
××
● The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
BATTERY VOLT [V] ××
● The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V] ××
● The accelerator pedal position sensor
signal voltage is displayed.
● ACCEL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
ACCEL SEN 2 [V] ×
THRTL SEN 1 [V] ××
● The throttle position sensor signal volt-
age is displayed.
● THRTL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal.
THRTL SEN 2 [V] ×
FUEL T/TMP SE
[°C] or [°F]
×
● The fuel temperature (determined by the
signal voltage of the fuel tank tempera-
ture sensor) is displayed.
INT/A TEMP SE
[°C] or [°F]
××
● The intake air temperature (determined
by the signal voltage of the intake air
temperature sensor) is indicated.
EVAP SYS PRES
[V]
×
● The signal voltage of EVAP control sys-
tem pressure sensor is displayed.
EC-132
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
FUEL LEVEL SE
[V]
×
● The signal voltage of the fuel level sen-
sor is displayed.
START SIGNAL
[ON/OFF]
××
● Indicates start signal status [ON/OFF]
computed by the ECM according to the
signals of engine speed and battery volt-
age.
● After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF]
××
● Indicates idle position [ON/OFF] com-
puted by ECM according to the acceler-
ator pedal position sensor signal.
AIR COND SIG
[ON/OFF]
××
● Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF]
××
● Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF]
××
● [ON/OFF] condition of the power steer-
ing system (determined by the signal
voltage of the power steering pressure
sensor signal) is indicated.
LOAD SIGNAL
[ON/OFF]
××
● Indicates [ON/OFF] condition from the
electrical load signal.
ON: Rear window defogger switch is ON
and/or lighting switch is in 2nd position.
OFF: Both rear window defogger switch
and lighting switch are OFF.
IGNITION SW
[ON/OFF]
×
● Indicates [ON/OFF] condition from igni-
tion switch signal.
HEATER FAN SW
[ON/OFF]
×
● Indicates [ON/OFF] condition from
heater fan switch signal.
BRAKE SW
[ON/OFF]
×
● Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec]
×
● Indicates the actual fuel injection pulse
width compensated by ECM according
to the input signals.
● When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2
[msec]
IGN TIMING
[BTDC]
×
● Indicates the ignition timing computed
by ECM according to the input signals.
● When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE [%]
● “Calculated load value” indicates the
value of the current air flow divided by
peak air flow.
MASS AIRFLOW
[g·m/s]
● Indicates the mass air flow computed by
ECM according to the signal voltage of
the mass air flow sensor.
PURG VOL C/V [%]
● Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.
● The opening becomes larger as the
value increases.
AIR COND RLY
[ON/OFF]
×
● The air conditioner relay control condi-
tion (determined by ECM according to
the input signals) is indicated.
FUEL PUMP RLY
[ON/OFF]
×
● Indicates the fuel pump relay control
condition determined by ECM according
to the input signals.
Monitored item
[Unit]
ECM
INPUT
SIGNALS
MAIN
SIGNALS
Description Remarks
TROUBLE DIAGNOSIS
EC-133
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VENT CONT/V
[ON/OFF]
● The control condition of the EVAP canis-
ter vent control valve (determined by
ECM according to the input signals) is
indicated.
ON: Closed
OFF: Open
THRTL RELAY
[ON/OFF]
×
● Indicates the throttle control motor relay
control condition determined by the
ECM according to the input signals.
COOLING FAN
[HI/OFF]
×
● The control condition of the cooling fan
(determined by ECM according to the
input signals) is indicated.
HI: High speed operation
OFF: Stop
HO2S2 HTR (B1)
[ON/OFF]
● Indicates [ON/OFF] condition of heated
oxygen sensor 2 heater determined by
ECM according to the input signals.
HO2S2 HTR (B2)
[ON/OFF]
I/P PULLY SPD
[rpm]
● Indicates the engine speed computed
from the turbine revolution sensor sig-
nal.
VEHICLE SPEED
[km/h] or [MPH]
● Indicates the vehicle speed computed
from the revolution sensor signal.
IDL A/V LEARN
[YET/CMPLT]
● Display the condition of idle air volume
learning
YET: Idle Air Volume Learning has not
been performed yet.
CMPLT: Idle Air Volume Learning has
already been performed successfully.
TRVL AFTER MIL
[km] or [mile]
● Distance traveled while MIL is activated.
A/F S1 HTR (B1)
[%]
● A/F sensor 1 heater control value com-
puted by ECM according to the input sig-
nals.
● The current flow to the heater becomes
larger as the value increases.
A/F S1 HTR (B2)
[%]
AC PRESS SEN [V]
● The signal voltage from the refrigerant
pressure sensor is displayed.
VHCL SPEED SE
[km/h] or [mph]
● The vehicle speed computed from the
vehicle speed signal sent from combina-
tion meter is displayed.
SET VHCL SPD*
1
[km/h] or [mph]
● The preset vehicle speed is displayed.
MAIN SW
[ON/OFF]
● Indicates [ON/OFF] condition from MAIN
switch signal.
CANCEL SW
[ON/OFF]
● Indicates [ON/OFF] condition from CAN-
CEL switch signal.
RESUME/ACC SW
[ON/OFF]
● Indicates [ON/OFF] condition from
RESUME/ACCELERATE switch signal.
SET SW
[ON/OFF]
● Indicates [ON/OFF] condition from SET/
COAST switch signal.
BRAKE SW1
[ON/OFF]
● Indicates [ON/OFF] condition from
ASCD brake switch signal.
Monitored item
[Unit]
ECM
INPUT
SIGNALS
MAIN
SIGNALS
Description Remarks
EC-134
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
*1: Models with ASCD
*2: Models with ICC
NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
DATA MONITOR (SPEC) MODE
Monitored Item
BRAKE SW2
[ON/OFF]
● Indicates [ON/OFF] condition of stop
lamp switch signal.
DIST SW*
2
[ON/OFF]
● Indicates [ON/OFF] condition from DIS-
TANCE switch signal.
VHCL SPD CUT
[NON/CUT]
● Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the
ASCD set speed.
CUT: Vehicle speed increased to exces-
sively high compared with the ASCD set
speed, and ASCD operation is cut off.
LO SPEED CUT*
1
[NON/CUT]
● Indicates the vehicle cruise condition.
NON: Vehicle speed is maintained at the
ASCD set speed.
CUT: Vehicle speed decreased to exces-
sively low compared with the ASCD set
speed, and ASCD operation is cut off.
AT OD MONITOR*
1
[ON/OFF]
● Indicates [ON/OFF] condition of A/T O/D
according to the input signal from the
TCM.
AT OD CANCEL*
1
[ON/OFF]
● Indicates [ON/OFF] condition of A/T O/D
cancel signal sent from the TCM.
CRUISE LAMP
[ON/OFF]
● Indicates [ON/OFF] condition of
CRUISE lamp determined by the ECM
according to the input signals.
SET LAMP*
1
[ON/OFF]
● Indicates [ON/OFF] condition of SET
lamp determined by the ECM according
to the input signals.
Voltage [V]
● Voltage, frequency, duty cycle or pulse
width measured by the probe.
● Only # is displayed if item is unable to
be measured.
● Figures with #s are temporary ones.
They are the same figures as an actual
piece of data which was just previously
measured.
Frequency [msec],
[Hz] or [%]
DUTY-HI
DUTY-LOW
PLS WIDTH-HI
PLS WIDTH-LOW
Monitored item
[Unit]
ECM
INPUT
SIGNALS
MAIN
SIGNALS
Description Remarks
Monitored item
[Unit]
ECM
INPUT
SIGNALS
MAIN
SIGNALS
Description Remarks
ENG SPEED [rpm] ××
● Indicates the engine speed computed
from the signal of the crankshaft position
sensor (POS) and camshaft position
sensor (PHASE).
MAS A/F SE-B1 [V] ××
● The signal voltage of the mass air flow
sensor specification is displayed.
● When engine is running specification
range is indicated.
TROUBLE DIAGNOSIS
EC-135
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NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
B/FUEL SCHDL
[msec]
×
● Base fuel schedule indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
● When engine is running specification
range is indicated.
A/F ALPHA-B1 [%]
A/F ALPHA-B2 [%]
×
● The mean value of the air-fuel ratio feed-
back correction factor per cycle is indi-
cated.
● When engine is running specification
range is indicated.
● This data also includes the data for
the air-fuel ratio learning control.
Monitored item
[Unit]
ECM
INPUT
SIGNALS
MAIN
SIGNALS
Description Remarks
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION
● Engine: Return to the original
trouble condition
● Change the amount of fuel injec-
tion using CONSULT-II.
If trouble symptom disappears, see
CHECK ITEM.
● Harness and connectors
● Fuel injector
● Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING
● Engine: Return to the original
trouble condition
● Timing light: Set
● Retard the ignition timing using
CONSULT-II.
If trouble symptom disappears, see
CHECK ITEM.
● Perform Idle Air Volume Learning.
POWER BAL-
ANCE
● Engine: After warming up, idle
the engine.
● A/C switch: OFF
● Selector lever: P or N
● Cut off each injector signal one at
a time using CONSULT-II.
Engine runs rough or dies.
● Harness and connectors
● Compression
● Fuel injector
● Power transistor
● Spark plug
● Ignition coil
COOLING FAN*
● Ignition switch: ON
● Turn the cooling fan HI and OFF
using CONSULT-II.
Cooling fan moves and stops.
● Harness and connectors
● Cooling fan motor
● IPDM E/R
ENG COOLANT
TEMP
● Engine: Return to the original
trouble condition
● Change the engine coolant tem-
perature using CONSULT-II.
If trouble symptom disappears, see
CHECK ITEM.
● Harness and connectors
● Engine coolant temperature sen-
sor
● Fuel injector
FUEL PUMP
RELAY
● Ignition switch: ON
(Engine stopped)
● Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound.
Fuel pump relay makes the operat-
ing sound.
● Harness and connectors
● Fuel pump relay
PURG VOL
CONT/V
● Engine: After warming up, run
engine at 1,500 rpm.
● Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.
Engine speed changes according to
the opening percent.
● Harness and connectors
● Solenoid valve
EC-136
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-54, "SYSTEM READINESS TEST (SRT) CODE" .
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
FUEL/T TEMP
SEN
● Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V
● Ignition switch: ON
(Engine stopped)
● Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound.
Solenoid valve makes an operating
sound.
● Harness and connectors
● Solenoid valve
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode Test item Condition Reference page
EVAPORATIVE
SYSTEM
PURG FLOW P0441
Refer to corresponding
trouble diagnosis for
DTC.
EC-304
EVP SML LEAK P0442/P1442* EC-309
EVP V/S LEAK P0456/P1456* EC-357
PURG VOL CN/V P1444 EC-531
A/F SEN1
A/F SEN1 (B1) P1276 EC-497
A/F SEN1 (B2) P1286 EC-497
A/F SEN1 (B1) P1278/P1279 EC-507, EC-519
A/F SEN1 (B2) P1288/P1289 EC-507, EC-519
HO2S2
HO2S2 (B1) P0139 EC-225
HO2S2 (B1) P1146 EC-415
HO2S2 (B1) P1147 EC-426
HO2S2 (B2) P0159 EC-225
HO2S2 (B2) P1166 EC-415
HO2S2 (B2) P1167 EC-426
TROUBLE DIAGNOSIS
EC-137
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REAL TIME DIAGNOSIS IN DATA MONITOR MODE (RECORDING VEHICLE DATA)
Description
CONSULT-II has two kinds of triggers and they can be selected by touching “SETTING” in “DATA MONITOR”
mode.
1. “AUTO TRIG” (Automatic trigger):
● The malfunction will be identified on the CONSULT-II screen
in real time.
In other words, DTC/1st trip DTC and malfunction item will be
displayed if the malfunction is detected by ECM.
At the moment a malfunction is detected by ECM, “MONI-
TOR” in “DATA MONITOR” screen is changed to “Recording
Data ... xx%” as shown in the figure, and the data after the
malfunction detection is recorded. Then when the percentage
reached 100%, “REAL-TIME DIAG” screen is displayed. If
“STOP” is touched on the screen during “Recording Data ...
xx%”, “REAL-TIME DIAG” screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by “TRIGGER POINT” and
“Recording Speed”. Refer to CONSULT-II Operation Manual.
2. “MANU TRIG” (Manual trigger):
● DTC/1st trip DTC and malfunction item will not be displayed
automatically on CONSULT-II screen even though a malfunc-
tion is detected by ECM.
DATA MONITOR can be performed continuously even though
a malfunction is detected.
SEF705Y
SEF707X
EC-138
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Operation
1. “AUTO TRIG”
● While trying to detect the DTC/1st trip DTC by performing the DTC Confirmation Procedure, be sure to
select to “DATA MONITOR (AUTO TRIG)” mode. You can confirm the malfunction at the moment it is
detected.
● While narrowing down the possible causes, CONSULT-II should be set in “DATA MONITOR (AUTO
TRIG)” mode, especially in case the incident is intermittent.
When you are inspecting the circuit by gently shaking (or twisting) the suspicious connectors, compo-
nents and harness in the DTC Confirmation Procedure, the moment a malfunction is found the DTC/1st
trip DTC will be displayed. (Refer to “INCIDENT SIMULATION TESTS” in GI-27, "
How to Perform Effi-
cient Diagnosis for an Electrical Incident" .)
2. “MANU TRIG”
● If the malfunction is displayed as soon as “DATA MONITOR” is selected, reset CONSULT-II to “MANU
TRIG”. By selecting “MANU TRIG” you can monitor and store the data. The data can be utilized for fur-
ther diagnosis, such as a comparison with the value for the normal operating condition.
PBIB0197E
TROUBLE DIAGNOSIS
EC-139
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Generic Scan Tool (GST) Function UBS00L0C
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO9141 is used as the protocol.
The name GST or Generic Scan Tool is used in this service manual.
FUNCTION
SEF139P
Diagnostic test mode Function
Service $01 READINESS TESTS
This diagnostic service gains access to current emission-related data values, including
analog inputs and outputs, digital inputs and outputs, and system status information.
Service $02 (FREEZE DATA)
This diagnostic service gains access to emission-related data value which were stored by
ECM during the freeze frame. For details, refer to EC-54, "
FREEZE FRAME DATA AND
1ST TRIP FREEZE FRAME DATA" .
Service $03 DTCs
This diagnostic service gains access to emission-related power train trouble codes which
were stored by ECM.
Service $04 CLEAR DIAG INFO
This diagnostic service can clear all emission-related diagnostic information. This
includes:
● Clear number of diagnostic trouble codes (Service $01)
● Clear diagnostic trouble codes (Service $03)
● Clear trouble code for freeze frame data (Service $01)
● Clear freeze frame data (Service $02)
● Reset status of system monitoring test (Service $01)
● Clear on board monitoring test results (Service $06 and $07)
Service $06 (ON BOARD TESTS)
This diagnostic service accesses the results of on board diagnostic monitoring tests of
specific components/systems that are not continuously monitored.
Service $07 (ON BOARD TESTS)
This diagnostic service enables the off board test drive to obtain test results for emission-
related powertrain components/systems that are continuously monitored during normal
driving conditions.
Service $08 —
This diagnostic service can close EVAP system in ignition switch ON position (Engine
stopped). When this diagnostic service is performed, the EVAP canister vent control
valve can be closed.
In the following conditions, this diagnostic service cannot function.
● Low ambient temperature
● Low battery voltage
● Engine running
● Ignition switch OFF
● Low fuel temperature
● Too much pressure is applied to EVAP system
Service $09 (CALIBRATION ID)
This diagnostic service enables the off-board test device to request specific vehicle infor-
mation such as Vehicle Identification Number (VIN) and Calibration IDs.
EC-140
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect GST to data link connector, which is located under LH
dash panel near the hood opener handle.
3. Turn ignition switch ON.
4. Enter the program according to instruction on the screen or in
the operation manual.
(*: Regarding GST screens in this section, sample screens are
shown.)
5. Perform each diagnostic service according to each service pro-
cedure.
For further information, see the GST Operation Manual of
the tool maker.
BBIA0369E
SEF398S
SEF416S
TROUBLE DIAGNOSIS
EC-141
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CONSULT-II Reference Value in Data Monitor UBS00L0D
Remarks:
● Specification data are reference values.
● Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data in
spite of the ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM
according to the signals input from the camshaft position sensor and other ignition timing related sensors.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED
● Run engine and compare CONSULT-II value with the tachometer indica-
tion.
Almost the same speed as the
tachometer indication.
MAS A/F SE-B1 See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
B/FUEL SCHDL See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
A/F ALPHA-B1
A/F ALPHA-B2
See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
COOLAN TEMP/S
● Engine: After warming up More than 70°C (158°F)
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at 2,000
rpm
Fluctuates around 1.5 V
HO2S2 (B1)
HO2S2 (B2)
● Warm-up condition
● After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load
Revving engine from idle to 3,000 rpm
quickly
0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
● Warm-up condition
● After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.
Revving engine from idle to 3,000 rpm
quickly.
LEAN ←→ RICH
VHCL SPEED SE
● Turn drive wheels and compare CONSULT-II value with the speedometer
indication.
Almost the same speed as the
speedometer indication
BATTERY VOLT
● Ignition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN 1
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
THRTL SEN 1
THRTL SEN 2*
● Ignition switch: ON
(Engine stopped)
● Selector lever: D
Accelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
EVAP SYS PRES
● Ignition switch: ON Approx. 1.8 - 4.8V
START SIGNAL
● Ignition switch: ON → START → ON OFF → ON → OFF
CLSD THL POS
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
AIR COND SIG
● Engine: After warming up, idle
the engine
Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)
ON
P/N POSI SW
● Ignition switch: ON
Selector lever: P or N ON
Selector lever: Except above OFF
PW/ST SIGNAL
● Engine: After warming up, idle
the engine
Steering wheel: Not being turned
(Forward direction)
OFF
Steering wheel: Being turned ON
LOAD SIGNAL
● Ignition switch: ON
Rear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF.
OFF
EC-142
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
IGNITION SW ● Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW
● Engine: After warming up, idle
the engine
Heater fan: Not operating OFF
Heater fan: Operating ON
BRAKE SW
● Ignition switch: ON
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2
● Engine: After warming up
● Selector lever: P or N
● Air conditioner switch: OFF
● No load
Idle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING
● Engine: After warming up
● Selector lever: P or N
● Air conditioner switch: OFF
● No load
Idle 10° - 20° BTDC
2,000 rpm 25° - 45° BTDC
CAL/LD VALUE
● Engine: After warming up
● Selector lever: P or N
● Air conditioner switch: OFF
● No load
Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW
● Engine: After warming up
● Selector lever: P or N
● Air conditioner switch: OFF
● No load
Idle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V
● Engine: After warming up
● Selector lever: P or N
● Air conditioner switch: OFF
● No load
Idle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)
0%
2,000 rpm —
AIR COND RLY
● Engine: After warming up, idle
the engine
Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor: Operates)
ON
FUEL PUMP RLY
● For 1 second after turning ignition switch ON
● Engine running or cranking
ON
● Except above conditions OFF
VENT CONT/V
● Ignition switch: ON OFF
THRTL RELAY
● Ignition switch: ON ON
COOLING FAN
● Engine: After warming up, idle
the engine
● Air conditioner switch: OFF
Engine coolant temperature: 99°C
(210°F) or less
OFF
Engine coolant temperature: 100°C
(212°F) or more
HI
HO2S2 HTR (B1)
HO2S2 HTR (B2)
● Engine speed is below 3,600 rpm after the following conditions are met.
– Engine: After warming up
– Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load
ON
● Engine speed: Above 3,600 rpm OFF
I/P PULLY SPD
● Vehicle speed: More than 20 km/h (12 MPH)
Almost the same speed as the
tachometer indication
VEHICLE SPEED
● Turn drive wheels and compare CONSULT-II value with the speedometer
indication.
Almost the same speed as the
speedometer indication
TRVL AFTER MIL
● Ignition switch: ON
Vehicle has traveled after MIL has
turned ON.
0 - 65,535 km
(0 - 40,723 mile)
MONITOR ITEM CONDITION SPECIFICATION
TROUBLE DIAGNOSIS
EC-143
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Revision: October 2005 2005 QX56
*: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, they differ from
ECM terminals voltage signal.
A/F S1 HTR (B1)
A/F S1 HTR (B2)
● Engine: After warming up, idle the engine 0 - 100%
AC PRESS SEN
● Ignition switch: ON (Engine stopped) Approx. 0V
● Engine: Idle
● Air conditioner switch: ON
1.0 - 4.0V
VHCL SPEED SE
● Turn drive wheels and compare CONSULT-II value with the speedometer
indication.
Almost the same speed as the
speedometer indication
SET VHCL SPD
● Engine: Running ASCD: Operating.
The preset vehicle speed is
displayed.
MAIN SW ● Ignition switch: ON
MAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW
● Ignition switch: ON
CANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW
● Ignition switch: ON
RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch:
Released
OFF
SET SW
● Ignition switch: ON
SET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DIST SW
● Ignition switch: ON
DISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1
● Ignition switch: ON
Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2
● Ignition switch: ON
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP ● Ignition switch: ON
MAIN switch: Pressed at the 1st time
→ at the 2nd time
ON → OFF
SET LAMP
● MAIN switch: ON
● Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH)
ASCD: Operating ON
ASCD: Not operating OFF
MONITOR ITEM CONDITION SPECIFICATION
EC-144
Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
Major Sensor Reference Graph in Data Monitor Mode UBS00L0E
The following are the major sensor reference graphs in “DATA MONITOR” mode.
CLSD THL POS, ACCEL SEN 1, THRTL SEN 1
Below is the data for “CLSD THL POS”, “ACCEL SEN 1” and “THRTL SEN 1” when depressing the accelera-
tor pedal with the ignition switch ON and with selector lever in D position.
The signal of “ACCEL SEN 1” and “THRTL SEN 1” should rise gradually without any intermittent drop or rise
after “CLSD THL POS” is changed from ON to OFF.
ENG SPEED, MAS A/F SE-B1, THRTL SEN 1, HO2S2 (B1), INJ PULSE-B1
Below is the data for “ENG SPEED”, “MAS A/F SE-B1”, “THRTL SEN 1”, “HO2S2 (B1)” and “INJ PULSE-B1”
when revving engine quickly up to 4,800 rpm under no load after warming up engine sufficiently.
Each value is for reference, the exact value may vary.
PBIB0198E
PBIB2445E
TROUBLE DIAGNOSIS
EC-145
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PBIB2099E
EC-146
Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
TROUBLE DIAGNOSIS - SPECIFICATION VALUE PFP:00031
Description UBS00L0F
The specification (SP) value indicates the tolerance of the value that is displayed in “DATA MONITOR (SPEC)”
mode of CONSULT-II during normal operation of the Engine Control System. When the value in “DATA MONI-
TOR (SPEC)” mode is within the SP value, the Engine Control System is confirmed OK. When the value in
“DATA MONITOR (SPEC)” mode is NOT within the SP value, the Engine Control System may have one or
more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
● B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board cor-
rection)
● A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
● MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Testing Condition UBS00L0G
● Vehicle driven distance: More than 5,000 km (3,017 miles)
● Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2
, 14.25 - 15.12 psi)
● Atmospheric temperature: 20 - 30°C (68 - 86°F)
● Engine coolant temperature: 75 - 95°C (167 - 203°F)
● Transmission: Warmed-up*
1
● Electrical load: Not applied*
2
● Engine speed: Idle
*1: After the engine is warmed up to normal operating temperature, drive vehicle until “ATF TEMP SE 1” (A/T
fluid temperature sensor signal) indicates more than 60°C (140°F).
*2: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
Inspection Procedure UBS00L0H
NOTE:
Perform “DATA MONITOR (SPEC)” mode in maximum scale display.
1. Perform EC-72, "
Basic Inspection" .
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”
and “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode with
CONSULT-II.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-147, "
Diagnostic Procedure" .
SEF601Z
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-147
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Diagnostic Procedure UBS00L0I
OVERALL SEQUENCE
PBIB2268E
EC-148
Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
PBIB2548E
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-149
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DETAILED PROCEDURE
1. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Confirm that the testing conditions are met. Refer to EC-146, "
Testing Condition" .
3. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR
(SPEC)” mode, and make sure that the each indication is within
the SP value.
NOTE:
Check “A/F ALPHA-B1”, “A/F ALPHA-B2” for approximately 1
minute because they may fluctuate. It is NG if the indication is
out of the SP value even a little.
OK or NG
OK >> GO TO 17.
NG (Less than the SP value)>>GO TO 2.
NG (More than the SP value)>>GO TO 3.
2. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 4.
NG (More than the SP value)>>GO TO 19.
3. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 6.
NG (More than the SP value)>>GO TO 6.
NG (Less than the SP value)>>GO TO 25.
4. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Stop the engine.
2. Disconnect PCV hose, and then plug it.
3. Start engine.
4. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> GO TO 5.
NG >> GO TO 6.
PBIB2369E
PBIB2332E
PBIB2332E
EC-150
Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
5. CHANGE ENGINE OIL
1. Stop the engine.
2. Change engine oil.
NOTE:
This symptom may occur when a large amount of gasoline is mixed with engine oil because of driving
conditions (such as when engine oil temperature does not rise enough since a journey distance is too
short during winter). The symptom will not be detected after changing engine oil or changing driving con-
dition.
>> INSPECTION END
6. CHECK FUEL PRESSURE
Check fuel pressure. (Refer to EC-94, "
FUEL PRESSURE CHECK" .)
OK or NG
OK >> GO TO 9.
NG (Fuel pressure is too high)>>Replace fuel pressure regulator, refer to EC-94, "
FUEL PRESSURE
CHECK" . GO TO 8.
NG (Fuel pressure is too low)>>GO TO 7.
7. DETECT MALFUNCTIONING PART
1. Check the following.
– Clogged and bent fuel hose and fuel tube
– Clogged fuel filter
– Fuel pump and its circuit (Refer to EC-637, "FUEL PUMP CIRCUIT" .)
2. If NG, repair or replace the malfunctioning part. (Refer to EC-94, "
FUEL PRESSURE CHECK" .)
If OK, replace fuel pressure regulator.
>> GO TO 8.
8. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 9.
9. PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine
speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
PBIB0133E
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-151
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10. DETECT MALFUNCTIONING PART
1. Check the following.
– Ignition coil and its circuit (Refer to EC-619, "IGNITION SIGNAL" .)
– Fuel injector and its circuit (Refer to EC-631, "INJECTOR CIRCUIT" .)
– Intake air leakage
– Low compression pressure (Refer to EM-58, "CHECKING COMPRESSION PRESSURE" .)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caused by leakage from fuel injector or clogging.)
>> GO TO 11.
11. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 12.
12. CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.
● For DTC P1271, P1281, refer to EC-459, "DTC Confirmation Procedure" .
● For DTC P1272, P1282, refer to EC-468, "DTC Confirmation Procedure" .
● For DTC P1273, P1283, refer to EC-477, "DTC Confirmation Procedure" .
● For DTC P1274, P1284, refer to EC-487, "DTC Confirmation Procedure" .
● For DTC P1276, P1286, refer to EC-497, "DTC Confirmation Procedure" .
● For DTC P1278, P1288, refer to EC-508, "DTC Confirmation Procedure" .
● For DTC P1279, P1289, refer to EC-520, "DTC Confirmation Procedure" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13. CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 15.
EC-152
Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
15. DISCONNECT AND RECONNECT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-104, "
Symptom Matrix Chart" .
17. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18. DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
– Engine oil level is too high
– Engine oil viscosity
– Belt tension of power steering, alternator, A/C compressor, etc. is excessive
– Noise from engine
– Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
– Valve clearance malfunction
– Intake valve timing control function malfunction
– Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
● Crushed air ducts
● Malfunctioning seal of air cleaner element
● Uneven dirt of air cleaner element
● Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
PBIB2332E
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-153
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20. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21. DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “DATA MONITOR (SPEC)” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-183, "DTC
P0102, P0103 MAF SENSOR" .
2. GO TO 29.
NG >> GO TO 23.
23. CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace mass air flow sensor, and
then GO TO 29.
24. REPLACE ECM
1. Replace ECM.
2. Perform initialization of NVIS(NATS) system and registration of all NVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
3. Perform EC-90, "
VIN Registration" .
4. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-90, "
Throttle Valve Closed Position Learning" .
6. Perform EC-91, "
Idle Air Volume Learning" .
>> GO TO 29.
PBIB2370E
EC-154
Revision: October 2005
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
2005 QX56
25. CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
● Crushed air ducts
● Malfunctioning seal of air cleaner element
● Uneven dirt of air cleaner element
● Improper specification of intake air system
OK or NG
OK >> GO TO 27.
NG >> Repair or replace malfunctioning part, and then GO TO 26.
26. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (Less than the SP value)>>GO TO 27.
27. CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “DATA MONITOR (SPEC)” mode, and
make sure that the indication is within the SP value.
OK or NG
OK >> GO TO 28.
NG (Less than the SP value)>>Replace mass air flow sensor, and
then GO TO 30.
28. CHECK INTAKE SYSTEM
Check for the cause of air leak after the mass air flow sensor. Refer to the following.
● Disconnection, looseness, and cracks in air duct
● Looseness of oil filler cap
● Disconnection of oil level gauge
● Open stuck, breakage, hose disconnection, or cracks of PCV valve
● Disconnection or cracks of EVAP purge hose, open stuck of EVAP canister purge volume control solenoid
valve
● Malfunctioning seal of rocker cover gasket
● Disconnection, looseness, or cracks of hoses, such as vacuum hose, connecting to intake air system
parts
● Malfunctioning seal of intake air system, etc.
>> GO TO 30.
29. CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-104, "
Symptom Matrix Chart" .
PBIB2370E
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-155
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30. CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and then make sure that the indication is within
the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-104, "
Symptom Matrix Chart" .
EC-156
Revision: October 2005
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
2005 QX56
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT PFP:00006
Description UBS00L0J
Intermittent incidents may occur. In many cases, the malfunction resolves itself (the part or circuit function
returns to normal without intervention). It is important to realize that the symptoms described in the customer's
complaint often do not recur on (1st trip) DTC visits. Realize also that the most frequent cause of intermittent
incidents occurrences is poor electrical connections. Because of this, the conditions under which the incident
occurred may not be clear. Therefore, circuit checks made as part of the standard diagnostic procedure may
not indicate the specific malfunctioning area.
Common Intermittent Incidents Report Situations
Diagnostic Procedure UBS00L0K
1. INSPECTION START
Erase (1st trip) DTCs. Refer to EC-62, "
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMA-
TION" .
>> GO TO 2.
2. CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. SEARCH FOR ELECTRICAL INCIDENT
Perform GI-27, "
How to Perform Efficient Diagnosis for an Electrical Incident" , “INCIDENT SIMULATION
TESTS”.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK CONNECTOR TERMINALS
Refer to GI-24, "
How to Check Terminal" , “HOW TO PROBE CONNECTORS”, “How to Check Enlarged Con-
tact Spring of Terminal”.
OK or NG
OK >> INSPECTION END
NG >> Repair or replace connector.
STEP in Work Flow Situation
2 The CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than [0] or [1t].
3 or 4 The symptom described by the customer does not recur.
5 (1st trip) DTC does not appear during the DTC Confirmation Procedure.
10 The Diagnostic Procedure for PXXXX does not indicate the malfunctioning area.
POWER SUPPLY AND GROUND CIRCUIT
EC-157
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POWER SUPPLY AND GROUND CIRCUIT PFP:24110
Wiring Diagram UBS00H0F
BBWA1670E
EC-158
Revision: October 2005
POWER SUPPLY AND GROUND CIRCUIT
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H0G
1. INSPECTION START
Start engine.
Is engine running?
Yes or No
Yes >> GO TO 8.
No >> GO TO 2.
2. CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● 10A fuse
● Harness for open or short between ECM and fuse
>> Repair harness or connectors.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
1 B ECM ground
[Engine is running]
● Idle speed
Body ground
109 L/W Ignition switch
[Ignition switch: OFF] 0V
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
115
116
B
B/W
ECM ground
[Engine is running]
● Idle speed
Body ground
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E
POWER SUPPLY AND GROUND CIRCUIT
EC-159
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4. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F32, E2
● Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
7. CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> Go to EC-619, "IGNITION SIGNAL" .
NG >> GO TO 8.
BBIA0354E
Continuity should exist.
Voltage: Battery voltage
PBIB2063E
EC-160
Revision: October 2005
POWER SUPPLY AND GROUND CIRCUIT
2005 QX56
8. CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and then OFF.
3. Check voltage between ECM terminals 119, 120 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 13.
NG (Battery voltage does not exist.)>>GO TO 9.
NG (Battery voltage exists for more than a few seconds.)>>GO TO
11.
9. CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check voltage between ECM terminal 111 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10. CHECK ECM POWER SUPPLY CIRCUIT-V
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminals 119, 120 and IPDM E/R terminal 3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
11. CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 111 and IPDM E/R terminal 7.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 16.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Voltage: After turning ignition switch OFF, battery
voltage will exist for a few seconds, then
drop approximately 0V.
PBIB1630E
Voltage: Battery voltage
PBIB1191E
Continuity should exist.
Continuity should exist.
POWER SUPPLY AND GROUND CIRCUIT
EC-161
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12. CHECK 20A FUSE
1. Disconnect 20A fuse from IPDM E/R.
2. Check 20A fuse.
OK or NG
OK >> GO TO 16.
NG >> Replace 20A fuse.
13. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Repair or replace ground connections.
14. CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F32, E2
● Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
16. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair open circuit or short to power in harness or connectors.
BBIA0354E
Continuity should exist.
EC-162
Revision: October 2005
POWER SUPPLY AND GROUND CIRCUIT
2005 QX56
Ground Inspection UBS00H0H
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:
● Remove the ground bolt or screw.
● Inspect all mating surfaces for tarnish, dirt, rust, etc.
● Clean as required to assure good contact.
● Reinstall bolt or screw securely.
● Inspect for “add-on” accessories which may be interfering with the ground circuit.
● If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one
eyelet make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to PG-29, "
Ground Distribution" .
PBIB1870E
DTC U1000, U1001 CAN COMMUNICATION LINE
EC-163
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DTC U1000, U1001 CAN COMMUNICATION LINE PFP:23710
Description UBS00H0I
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagnosis Logic UBS00H0J
*1: This self-diagnosis has the one trip detection logic.
*2: The MIL will not light up for this diagnosis.
DTC Confirmation Procedure UBS00H0K
1. Turn ignition switch ON and wait at least 3 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If 1st trip DTC is detected, go to EC-165, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
U1000*
1
1000*
1
CAN communication line
● ECM cannot communicate to other control
units.
● ECM cannot communicate for more than the
specified time.
● Harness or connectors
(CAN communication line is open or
shorted)
U1001*
2
1001*
2
EC-164
Revision: October 2005
DTC U1000, U1001 CAN COMMUNICATION LINE
2005 QX56
Wiring Diagram UBS00H0L
BBWA1671E
DTC U1000, U1001 CAN COMMUNICATION LINE
EC-165
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Diagnostic Procedure UBS00H0M
Go to LAN-3, "Precautions When Using CONSULT-II" .
EC-166
Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER PFP:226A0
Description UBS00H0N
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor Mode UBS00H0O
Specification data are reference values.
On Board Diagnosis Logic UBS00H0P
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)
Engine speed
Heated oxygen sensor 2
heater control
Heated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600 OFF
Below 3,600 rpm after the following conditions are met.
● Engine: After warming up
● Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no load
ON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)
● Engine speed is below 3,600 rpm after the following conditions are met.
– Engine: After warming up
– Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load
ON
● Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037
(Bank 1)
Heated oxygen sensor 2
heater control circuit low
The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)
● Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
● Heater oxygen sensor 2 heater
P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen sensor 2
heater control circuit high
The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to
ECM through the heated oxygen sensor 2
heater.)
● Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
● Heater oxygen sensor 2 heater
P0058
0058
(Bank 2)
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-167
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DTC Confirmation Procedure UBS00H0Q
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start the engine and keep the engine speed between 3,500 rpm
and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. If 1st trip DTC is detected, go to EC-171, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y
EC-168
Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
Wiring Diagram UBS00H0R
BANK 1
BBWA1672E
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-169
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
6GR
Heated oxygen sensor 2
heater (bank 1)
[Engine is running]
● Warm-up condition
● Engine speed is below 3,600 rpm after the
following conditions are met.
– Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load.
0 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
[Engine is running]
● Engine speed: Above 3,600 rpm.
BATTERY VOLTAGE
(11 - 14V)
EC-170
Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
BANK 2
BBWA1673E
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-171
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H0S
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
25 O/G
Heated oxygen sensor 2
heater (bank 2)
[Engine is running]
● Warm-up condition
● Engine speed is below 3,600 rpm after the
following conditions are met.
– Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load.
0 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
[Engine is running]
● Engine speed: Above 3,600 rpm.
BATTERY VOLTAGE
(11 - 14V)
BBIA0354E
EC-172
Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
2. CHECK HO2S2 POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Turn ignition switch ON.
3. Check voltage between HO2S2 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R connector E119
● 10A fuse
● Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair harness or connectors.
4. CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0435E
Voltage: Battery voltage
PBIB0112E
DTC
Te r mi na ls
Bank
ECM Sensor
P0037, P0038 6 2 1
P0057, P0058 25 2 2
Continuity should exist.
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-173
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5. CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-173, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H0T
HEATED OXYGEN SENSOR 2 HEATER
1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.
CAUTION:
● Discard any heated oxygen sensor which has been dropped
from a height of more than 0.5 m (19.7 in) onto a hard sur-
face such as a concrete floor; use a new one.
● Before installing new oxygen sensor, clean exhaust system
threads using Oxygen Sensor Thread Cleaner tool J-43897-
18 or J-43897-12 and approved anti-seize lubricant.
Removal and Installation UBS00H0U
HEATED OXYGEN SENSOR 2
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
Terminal No. Resistance
2 and 3 5.0 - 7.0 Ω at 25°C (77°F)
1 and 2, 3, 4
∞ Ω
(Continuity should not exist)
4 and 1, 2, 3
SEF249Y
EC-174
Revision: October 2005
DTC P0101 MAF SENSOR
2005 QX56
DTC P0101 MAF SENSOR PFP:22680
Component Description UBS00H0V
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor controls the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to the hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor Mode UBS00H0W
Specification data are reference values.
On Board Diagnosis Logic UBS00H0X
BBIA0355E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0101
0101
Mass air flow sensor circuit
range/performance problem
A)
A high voltage from the sensor is sent to ECM
under light load driving condition.
● Harness or connectors
(The sensor circuit is open or
shorted.)
● Mass air flow sensor
● EVAP control system pressure
sensor
● Intake air temperature sensor
B)
A low voltage from the sensor is sent to ECM
under heavy load driving condition.
● Harness or connectors
(The sensor circuit is open or
shorted.)
● Intake air leaks
● Mass air flow sensor
● EVAP control system pressure
sensor
● Intake air temperature sensor
DTC P0101 MAF SENSOR
EC-175
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DTC Confirmation Procedure UBS00H0Y
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
NOTE:
If engine will not start or stops soon, wait at least 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and warm it up to normal operating temperature.
4. Run engine for at least 10 seconds at idle speed.
5. If 1st trip DTC is detected, go to EC-178, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION B
CAUTION:
Always drive vehicle at a safe speed.
With CONSULT-II
1. Turn ignition switch ON.
2. Start engine and warm it up to normal operating temperature.
If engine cannot be started, go to EC-178, "
Diagnostic Procedure" .
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Check the voltage of “MAS A/F SE-B1” with “DATA MONITOR”.
5. Increases engine speed to about 4,000 rpm.
6. Monitor the linear voltage rise in response to engine speed
increases.
If NG, go to EC-178, "
Diagnostic Procedure" .
If OK, go to following step.
SEF174Y
SEF243Y
EC-176
Revision: October 2005
DTC P0101 MAF SENSOR
2005 QX56
7. Maintain the following conditions for at least 10 consecutive sec-
onds.
8. If 1st trip DTC is detected, go to EC-178, "
Diagnostic Procedure"
.
Overall Function Check UBS00H0Z
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor circuit. During this check, a 1st trip
DTC might not be confirmed.
With GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in
response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-178, "
Diagnostic Procedure" .
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Selector lever Suitable position
Driving location
Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB0199E
SEF534P
DTC P0101 MAF SENSOR
EC-177
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Wiring Diagram UBS00H10
BBWA1674E
EC-178
Revision: October 2005
DTC P0101 MAF SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H11
1. INSPECTION START
Which malfunction (A or B) is duplicated?
A or B
A >> GO TO 3.
B >> GO TO 2.
2. CHECK INTAKE SYSTEM
Check the following for connection.
● Air duct
● Vacuum hoses
● Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
51 W Mass air flow sensor
[Engine is running]
● Warm-up condition
● Idle speed
1.0 - 1.3V
[Engine is running]
● Warm-up condition
● Engine speed: 2,500 rpm.
1.7 - 2.1V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
DTC P0101 MAF SENSOR
EC-179
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3. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace ground connections.
4. CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow (MAF) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between MAF sensor terminal 2 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between IPDM E/R and mass air flow sensor
● Harness for open or short between mass air flow sensor and ECM
>> Repair harness or connectors.
BBIA0354E
BBIA0368E
Voltage: Battery voltage
PBIB1168E
EC-180
Revision: October 2005
DTC P0101 MAF SENSOR
2005 QX56
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-194, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace intake air temperature sensor.
9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10. CHECK MASS AIR FLOW SENSOR
Refer to EC-181, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
DTC P0101 MAF SENSOR
EC-181
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Component Inspection UBS00H12
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow-
ing conditions.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
● Crushed air ducts
● Malfunctioning seal of air cleaner element
● Uneven dirt of air cleaner element
● Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
● Crushed air ducts
● Malfunctioning seal of air cleaner element
● Uneven dirt of air cleaner element
● Improper specification of intake air system parts
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)
1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)
1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB2371E
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)
1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)
1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB1106E
EC-182
Revision: October 2005
DTC P0101 MAF SENSOR
2005 QX56
b. If NG, repair or replace malfunctioning part and perform step 2 to 3 again.
If OK, go to next step.
5. Turn ignition switch OFF.
6. Disconnect mass air flow sensor harness connector and reconnect it again.
7. Perform step 2 and 3 again.
8. If NG, clean or replace mass air flow sensor.
Removal and Installation UBS00H13
MASS AIR FLOW SENSOR
Refer to EM-14, "AIR CLEANER AND AIR DUCT" .
DTC P0102, P0103 MAF SENSOR
EC-183
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DTC P0102, P0103 MAF SENSOR PFP:22680
Component Description UBS00H14
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor controls the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to the hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor Mode UBS00H15
Specification data are reference values.
On Board Diagnosis Logic UBS00H16
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
BBIA0355E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0102
0102
Mass air flow sensor circuit
low input
An excessively low voltage from the sensor is
sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● Intake air leaks
● Mass air flow sensor
P0103
0103
Mass air flow sensor circuit
high input
An excessively high voltage from the sensor is
sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● Mass air flow sensor
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
EC-184
Revision: October 2005
DTC P0102, P0103 MAF SENSOR
2005 QX56
DTC Confirmation Procedure UBS00H17
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR DTC P0102
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait at least 5 seconds.
4. If DTC is detected, go to EC-186, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR DTC P0103
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If DTC is detected, go to EC-186, "
Diagnostic Procedure" .
If DTC is not detected, go to next step.
5. Start engine and wait at least 5 seconds.
6. If DTC is detected, go to EC-186, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
SEF058Y
SEF058Y
DTC P0102, P0103 MAF SENSOR
EC-185
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Wiring Diagram UBS00H18
BBWA1674E
EC-186
Revision: October 2005
DTC P0102, P0103 MAF SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H19
1. INSPECTION START
Which malfunction (P0102 or P0103) is duplicated?
P0102 or P0103
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2. CHECK INTAKE SYSTEM
Check the following for connection.
● Air duct
● Vacuum hoses
● Intake air passage between air duct to intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
51 W Mass air flow sensor
[Engine is running]
● Warm-up condition
● Idle speed
1.0 - 1.3V
[Engine is running]
● Warm-up condition
● Engine speed: 2,500 rpm.
1.7 - 2.1V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
DTC P0102, P0103 MAF SENSOR
EC-187
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3. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace ground connections.
4. CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow (MAF) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between MAF sensor terminal 2 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between IPDM E/R and mass air flow sensor
● Harness for open or short between mass air flow sensor and ECM
>> Repair harness or connectors.
BBIA0354E
BBIA0368E
Voltage: Battery voltage
PBIB1168E
EC-188
Revision: October 2005
DTC P0102, P0103 MAF SENSOR
2005 QX56
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK MASS AIR FLOW SENSOR
Refer to EC-189, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace mass air flow sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
DTC P0102, P0103 MAF SENSOR
EC-189
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Component Inspection UBS00H1A
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow-
ing conditions.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
● Crushed air ducts
● Malfunctioning seal of air cleaner element
● Uneven dirt of air cleaner element
● Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.
● Crushed air ducts
● Malfunctioning seal of air cleaner element
● Uneven dirt of air cleaner element
● Improper specification of intake air system parts
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)
1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)
1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB2371E
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)
1.0 - 1.3
2,500 rpm (Engine is warmed-up to
normal operating temperature.)
1.7 - 2.1
Idle to about 4,000 rpm* 1.0 - 1.3 to Approx. 2.4
PBIB1106E
EC-190
Revision: October 2005
DTC P0102, P0103 MAF SENSOR
2005 QX56
b. If NG, repair or replace malfunctioning part and perform step 2 to 3 again.
If OK, go to next step.
5. Turn ignition switch OFF.
6. Disconnect mass air flow sensor harness connector and reconnect it again.
7. Perform step 2 and 3 again.
8. If NG, clean or replace mass air flow sensor.
Removal and Installation UBS00H1B
MASS AIR FLOW SENSOR
Refer to EM-14, "AIR CLEANER AND AIR DUCT" .
DTC P0112, P0113 IAT SENSOR
EC-191
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DTC P0112, P0113 IAT SENSOR PFP:22630
Component Description UBS00H1C
The intake air temperature sensor is built-into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.
<Reference data>
*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis Logic UBS00H1D
DTC Confirmation Procedure UBS00H1E
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-193, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0355E
Intake air temperature
°C (°F)
Voltage* V Resistance kΩ
25 (77) 3.32 1.94 - 2.06
80 (176) 1.23 0.295 - 0.349
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0112
0112
Intake air temperature
sensor circuit low input
An excessively low voltage from the sensor is
sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● Intake air temperature sensor
P0113
0113
Intake air temperature
sensor circuit high input
An excessively high voltage from the sensor is
sent to ECM.
SEF058Y
EC-192
Revision: October 2005
DTC P0112, P0113 IAT SENSOR
2005 QX56
Wiring Diagram UBS00H1F
BBWA0879E
DTC P0112, P0113 IAT SENSOR
EC-193
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Diagnostic Procedure UBS00H1G
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor (intake air temperature sensor
is built-into) harness connector.
2. Turn ignition switch ON.
3. Check voltage between mass air flow sensor terminal 5 and
ground.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connectors.
BBIA0354E
BBIA0368E
Voltage: Approximately 5V
PBIB1169E
EC-194
Revision: October 2005
DTC P0112, P0113 IAT SENSOR
2005 QX56
3. CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow sensor terminal 6 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-194, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
5. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H1H
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor terminals 5 and
6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and Installation UBS00H1I
MASS AIR FLOW SENSOR
Refer to EM-14, "AIR CLEANER AND AIR DUCT" .
Continuity should exist.
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.94 - 2.06
BBIA0355E
SEF012P
DTC P0117, P0118 ECT SENSOR
EC-195
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DTC P0117, P0118 ECT SENSOR PFP:22630
Component Description UBS00H1J
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
<Reference data>
*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis Logic UBS00H1K
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
SEF594K
Engine coolant temperature
°C (°F)
Voltage* V Resistance kΩ
–10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC
No.
Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P0117
0117
Engine coolant temperature
sensor circuit low input
An excessively low voltage from the sensor is
sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● Engine coolant temperature sensor
P0118
0118
Engine coolant temperature
sensor circuit high input
An excessively high voltage from the sensor is
sent to ECM.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper-
ature sensor circuit
Engine coolant temperature will be determined by ECM based on the time after turning ignition switch ON
or START.
CONSULT-II displays the engine coolant temperature decided by ECM.
Condition
Engine coolant temperature decided
(CONSULT-II display)
Just as ignition switch is turned ON or START 40°C (104°F)
More than approx. 4 minutes after ignition ON or
START
80°C (176°F)
Except as shown above
40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while engine is running.
EC-196
Revision: October 2005
DTC P0117, P0118 ECT SENSOR
2005 QX56
DTC Confirmation Procedure UBS00H1L
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If DTC is detected, go to EC-198, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P0117, P0118 ECT SENSOR
EC-197
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H1M
BBWA1676E
EC-198
Revision: October 2005
DTC P0117, P0118 ECT SENSOR
2005 QX56
Diagnostic Procedure UBS00H1N
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between ECT sensor terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING RART
Check the following.
● Harness connector F26, F101
● Harness for open or short between ECM and engine coolant temperature sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0354E
Voltage: Approximately 5V
BBIA0370E
PBIB0080E
DTC P0117, P0118 ECT SENSOR
EC-199
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4. CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground or short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connector F26, F101
● Harness for open and short between ECT sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-199, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace engine coolant temperature sensor.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H1O
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
Continuity should exist.
PBIB2005E
EC-200
Revision: October 2005
DTC P0117, P0118 ECT SENSOR
2005 QX56
<Reference data>
2. If NG, replace engine coolant temperature sensor.
Removal and Installation UBS00H1P
ENGINE COOLANT TEMPERATURE SENSOR
Refer to EM-58, "CYLINDER HEAD" .
Engine coolant temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
DTC P0122, P0123 TP SENSOR
EC-201
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Revision: October 2005 2005 QX56
DTC P0122, P0123 TP SENSOR PFP:16119
Component Description UBS00H1Q
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
CONSULT-II Reference Value in Data Monitor Mode UBS00H1R
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagnosis Logic UBS00H1S
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
THRTL SEN 1
THRTL SEN 2*
● Ignition switch: ON
(Engine stopped)
● Selector lever: D
Accelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0122
0122
Throttle position sensor
2 circuit low input
An excessively low voltage from the TP sensor
2 is sent to ECM.
● Harness or connectors
(TP sensor 2 circuit is open or shorted.)
(APP sensor 2 circuit is shorted.)
● Electric throttle control actuator
(TP sensor 2)
● Accelerator pedal position sensor
P0123
0123
Throttle position sensor
2 circuit high input
An excessively high voltage from the TP sen-
sor 2 is sent to ECM.
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
EC-202
Revision: October 2005
DTC P0122, P0123 TP SENSOR
2005 QX56
DTC Confirmation Procedure UBS00H1T
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-204, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P0122, P0123 TP SENSOR
EC-203
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H1U
BBWA1677E
EC-204
Revision: October 2005
DTC P0122, P0123 TP SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H1V
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
47 Y
Sensor power supply
(Throttle position sensor)
[Ignition switch: ON] Approximately 5V
50 B Throttle position sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
Less than 4.75V
66 R
Sensor ground
(Throttle position sensor)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
69 W Throttle position sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
● Engine: Stopped
● Selector ever: D
● Accelerator pedal: Fully depressed
More than 0.36V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
BBIA0354E
DTC P0122, P0123 TP SENSOR
EC-205
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2. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal
2 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 2 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace open circuit.
4. CHECK THROTTLE POSITION SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5. CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-618, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
PBIB1480E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-203
91 APP sensor terminal 6 EC-613
EC-206
Revision: October 2005
DTC P0122, P0123 TP SENSOR
2005 QX56
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK THROTTLE POSITION SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 4 and ECM terminal 66.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK THROTTLE POSITION SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 69 and electric throttle control actuator terminal 3.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK THROTTLE POSITION SENSOR
Refer to EC-207, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
DTC P0122, P0123 TP SENSOR
EC-207
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Component Inspection UBS00H1W
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Turn ignition switch ON.
4. Set selector lever to D position.
5. Check voltage between ECM terminals 50 (TP sensor 1 signal),
69 (TP sensor 2 signal) and ground under the following condi-
tions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. Perform EC-90, "
Throttle Valve Closed Position Learning" .
8. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00H1X
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
Terminal Accelerator pedal Voltage
50
(Throttle position sensor 1)
Fully released More than 0.36V
Fully depressed Less than 4.75V
69
(Throttle position sensor 2)
Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB1530E
EC-208
Revision: October 2005
DTC P0125 ECT SENSOR
2005 QX56
DTC P0125 ECT SENSOR PFP:22630
Component Description UBS00H1Y
NOTE:
If DTC P0125 is displayed with P0117 or P0118, first perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-195, "
DTC P0117, P0118 ECT SENSOR" .
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.
<Reference data>
*: This data is reference value and is measured between ECM terminal 73 (Engine
coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis Logic UBS00H1Z
This self-diagnosis has the one trip detection logic.
SEF594K
Engine coolant temperature
°C (°F)
Voltage* V Resistance kΩ
–10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125
0125
Insufficient engine coolant
temperature for closed loop
fuel control
● Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
● Engine coolant temperature is insufficient for
closed loop fuel control.
● Harness or connectors
(High resistance in the circuit)
● Engine coolant temperature sensor
● Thermostat
DTC P0125 ECT SENSOR
EC-209
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Revision: October 2005 2005 QX56
DTC Confirmation Procedure UBS00H20
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Check that “COOLAN TEMP/S” is above 10°C (50°F).
If it is above 10°C (50°F), the test result will be OK.
If it is below 10°C (50°F), go to following step.
4. Start engine and run it for 65 minutes at idle speed.
If “COOLAN TEMP/S” increases to more than 10°C (50°F)
within 65 minutes, stop engine because the test result will
be OK.
5. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00H21
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-210, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
SEF174Y
BBIA0354E
EC-210
Revision: October 2005
DTC P0125 ECT SENSOR
2005 QX56
3. CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70°C (158°F)] condition, grasp lower radiator hose and confirm the engine
coolant does not flow.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-19, "
THERMOSTAT AND WATER PIPING" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-197, "
Wiring Diagram" .
>> INSPECTION END
Component Inspection UBS00H22
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.
<Reference data>
2. If NG, replace engine coolant temperature sensor.
Removal and Installation UBS00H23
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-19, "THERMOSTAT AND WATER PIPING" .
PBIB2005E
Engine coolant temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
DTC P0127 IAT SENSOR
EC-211
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Revision: October 2005 2005 QX56
DTC P0127 IAT SENSOR PFP:22630
Component Description UBS00H24
The intake air temperature sensor is built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.
<Reference data>
*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis Logic UBS00H25
DTC Confirmation Procedure UBS00H26
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Wait until engine coolant temperature is less than 90°C (194°F)
a. Turn ignition switch ON.
BBIA0355E
Intake air temperature
°C (°F)
Voltage* V Resistance kΩ
25 (77) 3.32 1.94 - 2.06
80 (176) 1.23 0.295 - 0.349
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127
Intake air temperature
too high
Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.
● Harness or connectors
(The sensor circuit is open or shorted)
● Intake air temperature sensor
EC-212
Revision: October 2005
DTC P0127 IAT SENSOR
2005 QX56
b. Select “DATA MONITOR” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90°C (194°F),
turn ignition switch OFF and cool down engine.
● Perform the following steps before engine coolant tempera-
ture is above 90°C (194°F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con-
secutive seconds.
6. If 1st trip DTC is detected, go to EC-212, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00H27
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-213, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-192, "
Wiring Diagram" .
>> INSPECTION END
SEF189Y
BBIA0354E
DTC P0127 IAT SENSOR
EC-213
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Component Inspection UBS00H28
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor).
Removal and Installation UBS00H29
MASS AIR FLOW SENSOR
Refer to EM-14, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.94 - 2.06
BBIA0355E
SEF012P
EC-214
Revision: October 2005
DTC P0128 THERMOSTAT FUNCTION
2005 QX56
DTC P0128 THERMOSTAT FUNCTION PFP:21200
On Board Diagnosis Logic UBS00H2A
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation Procedure UBS00H2B
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
● For best results, perform at ambient temperature of –10°C (14°F) or higher.
● For best results, perform at engine coolant temperature of –10°C (14°F) to 60°C (140°F).
WITH CONSULT-II
1. Replace thermostat with new one. Refer to CO-19, "THERMOSTAT AND WATER PIPING" . Use only a
genuine NISSAN thermostat as a replacement. If an incorrect thermostat is used, the MIL may come on.
2. Turn ignition switch ON.
3. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-II.
4. Check that the “COOLAN TEMP/S” is above 60°C (140°F).
If it is below 60°C (140°F), go to following step.
If it is above 60°C (140°F), cool down the engine to less than 60°C (140°F), then retry from step 1.
5. Drive vehicle for 10 consecutive minutes under the following conditions.
If 1st trip DTC is detected, go to EC-214, "
Diagnostic Procedure" .
WITH GST
1. Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00H2C
1. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-215, "
Component Inspection" .
OK or NG
OK >> INSPECTION END
NG >> Replace engine coolant temperature sensor.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128
Thermostat function
The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough.
● Thermostat
● Leakage from sealing portion of thermostat
● Engine coolant temperature sensor
VHCL SPEED SE 80 - 120 km/h (50 - 75 MPH)
DTC P0128 THERMOSTAT FUNCTION
EC-215
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Component Inspection UBS00H2D
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals as shown in the figure.
<Reference data>
2. If NG, replace engine coolant temperature sensor.
Removal and Installation UBS00H2E
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-19, "THERMOSTAT AND WATER PIPING" .
PBIB2005E
Temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.0
90 (194) 0.236 - 0.260
SEF012P
EC-216
Revision: October 2005
DTC P0138, P0158 HO2S2
2005 QX56
DTC P0138, P0158 HO2S2 PFP:226A0
Component Description UBS00H2F
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor Mode UBS00H2G
Specification data are reference values.
On Board Diagnosis Logic UBS00H2H
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the voltage is unusually high during
the various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
● Warm-up condition
● After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.
Revving engine from idle to 3,000 rpm
quickly.
0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
LEAN ←→ RICH
PBIB1848E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0138
0138
(Bank 1)
Heated oxygen sensor
2 circuit high voltage
An excessively high voltage from the sensor is
sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted)
● Heated oxygen sensor 2
P0158
0158
(Bank 2)
DTC P0138, P0158 HO2S2
EC-217
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DTC Confirmation Procedure UBS00H2I
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 2 minutes.
6. If 1st trip DTC is detected, go to EC-221, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y
EC-218
Revision: October 2005
DTC P0138, P0158 HO2S2
2005 QX56
Wiring Diagram UBS00H2J
BANK 1
BBWA1678E
DTC P0138, P0158 HO2S2
EC-219
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
55 R
Heated oxygen sensor 2
(bank 1)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
EC-220
Revision: October 2005
DTC P0138, P0158 HO2S2
2005 QX56
BANK 2
BBWA1679E
DTC P0138, P0158 HO2S2
EC-221
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H2K
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
74 L
Heated oxygen sensor 2
(bank 2)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
BBIA0354E
EC-222
Revision: October 2005
DTC P0138, P0158 HO2S2
2005 QX56
2. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Continuity should exist.
BBIA0435E
DTC
Te r mi na ls
Bank
ECM Sensor
P0138 55 1 1
P0158 74 1 2
Continuity should exist.
DTC
Te r mi na ls
Bank
ECM Sensor
P0138 55 1 1
P0158 74 1 2
Continuity should not exist.
DTC P0138, P0158 HO2S2
EC-223
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4. CHECK HO2S2 CONNECTOR FOR WATER
Check HO2S2 connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-223, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H2L
HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.
Water should not exist.
SEF174Y
PBIB1672E
EC-224
Revision: October 2005
DTC P0138, P0158 HO2S2
2005 QX56
7. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.58V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18V at least once when the “FUEL INJECTION” is −25%.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage is above 0.58V at step 6, step 7 is not neces-
sary.
7. Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new oxygen sensor, clean exhaust system threads (using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
Removal and Installation UBS00H2M
HEATED OXYGEN SENSOR 2
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
PBIB2636E
PBIB2054E
DTC P0139, P0159 HO2S2
EC-225
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DTC P0139, P0159 HO2S2 PFP:226A0
Component Description UBS00H2N
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor Mode UBS00H2O
Specification data are reference values.
On Board Diagnosis Logic UBS00H2P
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the switching response of the sen-
sor's voltage is faster than specified during the various driving condi-
tion such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
● Warm-up condition
● After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.
Revving engine from idle to 3,000 rpm
quickly.
0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
LEAN ←→ RICH
SEF302U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139
0139
(Bank 1)
Heated oxygen sensor
2 circuit slow response
It takes more time for the sensor to respond
between rich and lean than the specified time.
● Harness or connectors
(The sensor circuit is open or shorted)
● Heated oxygen sensor 2
● Fuel pressure
● Fuel injector
● Intake air leaks
P0159
0159
(Bank 2)
EC-226
Revision: October 2005
DTC P0139, P0159 HO2S2
2005 QX56
DTC Confirmation Procedure UBS00H2Q
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70°C
(158°F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70°C (158°F).
7. Open engine hood.
8. Select “HO2S2 (B1) P0139” or “HO2S2 (B2) P0159” of “HO2S2” in “DTC WORK SUPPORT” mode with
CONSULT-II.
9. Start engine and following the instruction of CONSULT-II.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”.
If “NG” is displayed, refer to EC-231, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function Check UBS00H2R
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
SEF174Y
PBIB2374E
DTC P0139, P0159 HO2S2
EC-227
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6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
A change of voltage should be more than 0.06V for 1 sec-
ond during this procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
A change of voltage should be more than 0.06V for 1 sec-
ond during this procedure.
8. If NG, go to EC-231, "
Diagnostic Procedure" .
PBIB2054E
EC-228
Revision: October 2005
DTC P0139, P0159 HO2S2
2005 QX56
Wiring Diagram UBS00H2S
BANK 1
BBWA1678E
DTC P0139, P0159 HO2S2
EC-229
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
55 R
Heated oxygen sensor 2
(bank 1)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
EC-230
Revision: October 2005
DTC P0139, P0159 HO2S2
2005 QX56
BANK 2
BBWA1679E
DTC P0139, P0159 HO2S2
EC-231
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H2T
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
74 L
Heated oxygen sensor 2
(bank 2)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
BBIA0354E
EC-232
Revision: October 2005
DTC P0139, P0159 HO2S2
2005 QX56
2. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode
with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart
and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-236, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-245, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 3.
SEF968Y
BBIA0368E
DTC P0139, P0159 HO2S2
EC-233
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3. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Continuity should exist.
BBIA0435E
DTC
Terminals
Bank
ECM Sensor
P0139 55 1 1
P0159 74 1 2
Continuity should exist.
DTC
Terminals
Bank
ECM Sensor
P0139 55 1 1
P0159 74 1 2
Continuity should not exist.
EC-234
Revision: October 2005
DTC P0139, P0159 HO2S2
2005 QX56
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-234, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H2U
HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.
7. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.58V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18V at least once when the “FUEL INJECTION” is −25%.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
SEF174Y
PBIB1672E
PBIB2636E
DTC P0139, P0159 HO2S2
EC-235
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Revision: October 2005 2005 QX56
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage is above 0.58V at step 6, step 7 is not neces-
sary.
7. Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and Installation UBS00H2V
HEATED OXYGEN SENSOR 2
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
PBIB2054E
EC-236
Revision: October 2005
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION PFP:16600
On Board Diagnosis Logic UBS00L0L
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the A/F sensors 1. The ECM calcu-
lates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation Procedure UBS00L0M
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0171 or P0174 should be detected at this
stage, if a malfunction exists. If so, go to EC-240, "
Diagnostic
Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to
(1st trip) Freeze Frame Data for 10 minutes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1
Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0171
0171
(Bank 1)
Fuel injection system too
lean
● Fuel injection system does not operate properly.
● The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.)
● Intake air leaks
● A/F sensor 1
● Fuel injector
● Exhaust gas leaks
● Incorrect fuel pressure
● Lack of fuel
● Mass air flow sensor
● Incorrect PCV hose connection
P0174
0174
(Bank 2)
SEF968Y
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition
When the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-237
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7. If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine starts, go to EC-240, "
Diagnostic Procedure" .
If engine does not start, check exhaust and intake air leak visually.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST. Make sure DTC P0102 is
detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine again and let it idle for at least 10 minutes.
9. Select Service $07 with GST. The 1st trip DTC P0171 or P0174
should be detected at this stage, if a malfunction exists. If so, go
to EC-240, "
Diagnostic Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
10. If it is difficult to start engine at step 8, the fuel injection system has a malfunction.
11. Crank engine while depressing accelerator pedal. If engine starts, go to EC-240, "
Diagnostic Procedure" .
If engine does not start, check exhaust and intake air leak visually.
BBIA0368E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition
When the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
EC-238
Revision: October 2005
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
Wiring Diagram UBS00L0N
BANK 1
BBWA1680E
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-239
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BANK 2
BBWA1681E
EC-240
Revision: October 2005
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
Diagnostic Procedure UBS00L0O
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
PBIB1216E
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-241
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3. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
A/F sensor 1 terminal ECM terminal
Bank 1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
BBIA0376E
EC-242
Revision: October 2005
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
4. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-94, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Fuel pump and circuit (Refer to EC-637, "FUEL PUMP CIRCUIT" .)
● Fuel pressure regulator (Refer to EC-94, "FUEL PRESSURE CHECK" .)
● Fuel lines
● Fuel filter for clogging
>> Repair or replace.
6. CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
grounds. Refer to EC-174, "
DTC P0101 MAF SENSOR" .
At idling: Approximately 350 kPa (3.57 kg/cm
2
, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
DTC P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-243
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7. CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
OK or NG
OK >> GO TO 8.
NG >> Perform trouble diagnosis for INJECTORS, refer to EC-
631, "INJECTOR CIRCUIT" .
8. CHECK INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch OFF.
3. Disconnect all injector harness connectors.
4. Remove injector gallery assembly. Refer to EM-29, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
5. For DTC P0171, reconnect injector harness connectors on bank 1.
For DTC P0174, reconnect injector harness connectors on bank 2.
6. Disconnect all ignition coil harness connectors.
7. Prepare pans or saucers under each injector.
8. Crank engine for about 3 seconds.
For DTC P0171, make sure that fuel sprays out from injectors
on bank 1.
For DTC P0174, make sure that fuel sprays out from injectors
on bank 2.
OK or NG
OK >> GO TO 9.
NG >> Replace injectors from which fuel does not spray out.
Always replace O-ring with new ones.
PBIB0133E
Clicking noise should be heard.
PBIB1986E
Fuel should be sprayed evenly for each injector.
PBIB1726E
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-245
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DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION PFP:16600
On Board Diagnosis Logic UBS00L0P
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal from the A/F sensors 1. The ECM calcu-
lates the necessary compensation to correct the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation Procedure UBS00L0Q
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Select “DATA MONITOR” mode with CONSULT-II.
6. Start engine again and let it idle for at least 10 minutes.
The 1st trip DTC P0172, P0175 should be detected at this stage,
if a malfunction exists. If so, go to EC-249, "
Diagnostic Proce-
dure" .
NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to
(1st trip) Freeze Frame Data for 10 minutes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
7. If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal.
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1
Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0172
0172
(Bank 1)
Fuel injection system too
rich
● Fuel injection system does not operate properly.
● The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.)
● A/F sensor 1
● Fuel injector
● Exhaust gas leaks
● Incorrect fuel pressure
● Mass air flow sensor
P0175
0175
(Bank 2)
SEF968Y
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition
When the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
EC-246
Revision: October 2005
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
If engine starts, go to EC-249, "Diagnostic Procedure" . If engine does not start, remove spark plugs and
check for fouling, etc.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Select Service $03 with GST. Make sure DTC P0102 is
detected.
6. Select Service $04 with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select Service $07 with GST. The 1st trip DTC P0172 or P0175
should be detected at this stage, if a malfunction exists. If so, go
to EC-249, "
Diagnostic Procedure" .
NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
9. If it is difficult to start engine at step 7, the fuel injection system has a malfunction.
10. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-249, "
Diagnostic Procedure" . If engine does not start, remove spark plugs and
check for fouling, etc.
BBIA0368E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition
When the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-247
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Wiring Diagram UBS00L0R
BANK 1
BBWA1680E
EC-248
Revision: October 2005
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
BANK 2
BBWA1681E
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-249
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Diagnostic Procedure UBS00L0S
1. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
PBIB1216E
EC-250
Revision: October 2005
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
3. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
A/F sensor 1 terminal ECM terminal
Bank 1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
BBIA0376E
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-251
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4. CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
2. Install fuel pressure gauge and check fuel pressure. Refer to EC-94, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Fuel pump and circuit (Refer to EC-637, "FUEL PUMP CIRCUIT" .)
● Fuel pressure regulator (Refer to EC-94, "FUEL PRESSURE CHECK" .)
>> Repair or replace.
6. CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Install all removed parts.
2. Check “MASS AIR FLOW” in “DATA MONITOR” mode with CONSULT-II.
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 7.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
grounds. Refer to EC-174, "
DTC P0101 MAF SENSOR" .
At idling: Approximately 350 kPa (3.57 kg/cm
2
, 51 psi)
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
EC-252
Revision: October 2005
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
2005 QX56
7. CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
OK or NG
OK >> GO TO 8.
NG >> Perform trouble diagnosis for INJECTORS, refer to EC-
631, "INJECTOR CIRCUIT" .
8. CHECK INJECTOR
1. Remove injector assembly. Refer to EM-29, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
2. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
3. Disconnect all injector harness connectors.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injectors.
6. Crank engine for about 3 seconds.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip.)>>GO TO 9.
NG (Drips.)>>Replace the injectors from which fuel is dripping. Always replace O-ring with new one.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
PBIB0133E
Clicking noise should be heard.
PBIB1986E
DTC P0181 FTT SENSOR
EC-253
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DTC P0181 FTT SENSOR PFP:22630
Component Description UBS00H34
The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.
<Reference data>
*: This data is reference value and is measured between ECM terminal 107 (Fuel
tank temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis Logic UBS00H35
DTC Confirmation Procedure UBS00H36
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 10 seconds.
If the result is NG, go to EC-256, "
Diagnostic Procedure" .
If the result is OK, go to following step.
4. Check “COOLAN TEMP/S” value.
If “COOLAN TEMP/S” is less than 60°C (140°F), the result will
be OK.
If “COOLAN TEMP/S” is above 60°C (140°F), go to the following
step.
5. Cool engine down until “COOLAN TEMP/S” is less than 60°C
(140°F).
6. Wait at least 10 seconds.
7. If 1st trip DTC is detected, go to EC-256, "
Diagnostic Procedure" .
BBIA0583E
Fluid temperature
°C (°F)
Voltage*
V
Resistance
kΩ
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0181
0181
Fuel tank temperature
sensor circuit range/
performance
Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage sig-
nals from engine coolant temperature sensor
and intake air temperature sensor.
● Harness or connectors
(The sensor circuit is open or shorted)
● Fuel tank temperature sensor
SEF174Y
EC-254
Revision: October 2005
DTC P0181 FTT SENSOR
2005 QX56
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC P0181 FTT SENSOR
EC-255
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Wiring Diagram UBS00H37
BBWA1682E
EC-256
Revision: October 2005
DTC P0181 FTT SENSOR
2005 QX56
Diagnostic Procedure UBS00H38
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
2. Turn ignition switch ON.
3. Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
BBIA0354E
BBIA0583E
Voltage: Approximately 5V
PBIB0932E
DTC P0181 FTT SENSOR
EC-257
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4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
>> Repair harness or connector.
5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination meter harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 3 and combination
meter terminal 16. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E152, M31
● Harness for open or short between “fuel level sensor unit and fuel pump” and combination meter
>> Repair open circuit or short to ground or short to power in harness or connector.
7. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-258, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace “fuel level sensor unit and fuel pump”.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
EC-258
Revision: October 2005
DTC P0181 FTT SENSOR
2005 QX56
Component Inspection UBS00H39
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 3 and 4 by heating with hot water or heat gun as
shown in the figure.
Removal and Installation UBS00H3A
FUEL TANK TEMPERATURE SENSOR
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
Temperature °C (°F) Resistance kΩ
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
SEF476YA
DTC P0182, P0183 FTT SENSOR
EC-259
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DTC P0182, P0183 FTT SENSOR PFP:22630
Component Description UBS00H3B
The fuel tank temperature sensor is used to detect the fuel tempera-
ture inside the fuel tank. The sensor modifies a voltage signal from
the ECM. The modified signal returns to the ECM as the fuel temper-
ature input. The sensor uses a thermistor which is sensitive to the
change in temperature. The electrical resistance of the thermistor
decreases as temperature increases.
<Reference data>
*: This data is reference value and is measured between ECM terminal 107 (Fuel
tank temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis Logic UBS00H3C
DTC Confirmation Procedure UBS00H3D
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-261, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0583E
Fluid temperature
°C (°F)
Voltage*
V
Resistance
kΩ
20 (68) 3.5 2.3 - 2.7
50 (122) 2.2 0.79 - 0.90
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0182
0182
Fuel tank temperature
sensor circuit low input
An excessively low voltage from the sensor is
sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● Fuel tank temperature sensor
P0183
0183
Fuel tank temperature
sensor circuit high input
An excessively high voltage from the sensor is
sent to ECM.
SEF174Y
EC-260
Revision: October 2005
DTC P0182, P0183 FTT SENSOR
2005 QX56
Wiring Diagram UBS00H3E
BBWA1682E
DTC P0182, P0183 FTT SENSOR
EC-261
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Diagnostic Procedure UBS00H3F
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
2. Turn ignition switch ON.
3. Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
BBIA0354E
BBIA0583E
Voltage: Approximately 5V
PBIB0932E
EC-262
Revision: October 2005
DTC P0182, P0183 FTT SENSOR
2005 QX56
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
>> Repair harness or connector.
5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination meter harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 3 and combination
meter terminal 16. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E152, M31
● Harness for open or short between “fuel level sensor unit and fuel pump” and combination meter
>> Repair open circuit or short to ground or short to power in harness or connector.
7. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-263, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace “fuel level sensor unit and fuel pump”.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
DTC P0182, P0183 FTT SENSOR
EC-263
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Component Inspection UBS00H3G
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.
2. Check resistance between “fuel level sensor unit and fuel pump”
terminals 3 and 4 by heating with hot water or heat gun as
shown in the figure.
Removal and Installation UBS00H3H
FUEL TANK TEMPERATURE SENSOR
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
Temperature °C (°F) Resistance kΩ
20 (68) 2.3 - 2.7
50 (122) 0.79 - 0.90
SEF476YA
EC-264
Revision: October 2005
DTC P0222, P0223 TP SENSOR
2005 QX56
DTC P0222, P0223 TP SENSOR PFP:16119
Component Description UBS00H3I
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
CONSULT-II Reference Value in Data Monitor Mode UBS00H3J
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagnosis Logic UBS00H3K
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
THRTL SEN 1
THRTL SEN 2*
● Ignition switch: ON
(Engine stopped)
● Selector lever: D
Accelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0222
0222
Throttle position sensor
1 circuit low input
An excessively low voltage from the TP sensor
1 is sent to ECM.
● Harness or connectors
(TP sensor 1 circuit is open or shorted.)
(APP sensor 2 circuit is shorted.)
● Electric throttle control actuator
(TP sensor 1)
● Accelerator pedal position sensor
P0223
0223
Throttle position sensor
1 circuit high input
An excessively high voltage from the TP sen-
sor 1 is sent to ECM.
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
DTC P0222, P0223 TP SENSOR
EC-265
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DTC Confirmation Procedure UBS00H3L
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-267, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
EC-266
Revision: October 2005
DTC P0222, P0223 TP SENSOR
2005 QX56
Wiring Diagram UBS00H3M
BBWA1683E
DTC P0222, P0223 TP SENSOR
EC-267
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H3N
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
47 Y
Sensor power supply
(Throttle position sensor)
[Ignition switch: ON] Approximately 5V
50 B Throttle position sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
Less than 4.75V
66 R
Sensor ground
(Throttle position sensor)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
69 W Throttle position sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
More than 0.36V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
BBIA0354E
EC-268
Revision: October 2005
DTC P0222, P0223 TP SENSOR
2005 QX56
2. CHECK THROTTLE POSITION SENSOR 1 POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal
2 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3. CHECK THROTTLE POSITION SENSOR 1 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 2 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace open circuit.
4. CHECK THROTTLE POSITION SENSOR 1 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5. CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-618, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
BBIA0371E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-266
91 APP sensor terminal 6 EC-613
DTC P0222, P0223 TP SENSOR
EC-269
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6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK THROTTLE POSITION SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 4 and ECM terminal 66.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK THROTTLE POSITION SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 50 and electric throttle control actuator terminal 1.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK THROTTLE POSITION SENSOR
Refer to EC-270, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
EC-270
Revision: October 2005
DTC P0222, P0223 TP SENSOR
2005 QX56
Component Inspection UBS00H3O
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Turn ignition switch ON.
4. Set selector lever to D position.
5. Check voltage between ECM terminals 50 (TP sensor 1 signal),
69 (TP sensor 2 signal) and ground under the following condi-
tions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. Perform EC-90, "
Throttle Valve Closed Position Learning" .
8. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00H3P
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
Terminal Accelerator pedal Voltage
50
(Throttle position sensor 1)
Fully released More than 0.36V
Fully depressed Less than 4.75V
69
(Throttle position sensor 2)
Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB1530E
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
EC-271
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DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
PFP:00000
On Board Diagnosis Logic UBS00L0T
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the crank-
shaft position (CKP) sensor (POS) signal to vary, ECM can determine that a misfire is occurring.
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the 1st trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to over-
heating, the MIL will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MIL will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MIL will remain on.
If another misfire condition occurs that can damage the TWC, the MIL will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MIL will only
light when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sen-
sor signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC Confirmation Procedure UBS00L0U
CAUTION:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws when driv-
ing.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
Sensor Input signal to ECM ECM function
Crankshaft position sensor (POS) Engine speed On board diagnosis of misfire
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0300
0300
Multiple cylinder misfire
detected
Multiple cylinder misfire.
● Improper spark plug
● Insufficient compression
● Incorrect fuel pressure
● The injector circuit is open or shorted
● Fuel injector
● Intake air leak
● The ignition signal circuit is open or
shorted
● Lack of fuel
● Signal plate
● Air fuel ratio (A/F) sensor 1
● Incorrect PCV hose connection
P0301
0301
No.1 cylinder misfire
detected
No. 1 cylinder misfires.
P0302
0302
No. 2 cylinder misfire
detected
No. 2 cylinder misfires.
P0303
0303
No. 3 cylinder misfire
detected
No. 3 cylinder misfires.
P0304
0304
No. 4 cylinder misfire
detected
No. 4 cylinder misfires.
P0305
0305
No. 5 cylinder misfire
detected
No. 5 cylinder misfires.
P0306
0306
No. 6 cylinder misfire
detected
No. 6 cylinder misfires.
P0307
0307
No. 7 cylinder misfire
detected
No. 7 cylinder misfires.
P0308
0308
No. 8 cylinder misfire
detected
No. 8 cylinder misfires.
EC-272
Revision: October 2005
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
2005 QX56
WITH CONSULT-II
1. Turn ignition switch ON, and select “DATA MONITOR” mode
with CONSULT-II.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Restart engine and let it idle for about 15 minutes.
5. If 1st trip DTC is detected, go to EC-272, "
Diagnostic Procedure"
.
NOTE:
If 1st trip DTC is not detected during above procedure, perform-
ing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for a certain
time. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
The time to driving varies according to the engine speed in the freeze frame data.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00L0V
1. CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
3. Check PCV hose connection.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2. CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace it.
PBIB0164E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature
(T) condition
When the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
Engine speed Time
Around 1,000 rpm Approximately 10 minutes
Around 2,000 rpm Approximately 5 minutes
More than 3,000 rpm Approximately 3.5 minutes
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
EC-273
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3. PERFORM POWER BALANCE TEST
With CONSULT-II
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Is there any cylinder which does not produce a momentary
engine speed drop?
Without CONSULT-II
When disconnecting each injector harness connector one at a time, is there any cylinder which does not pro-
duce a momentary engine speed drop?
Yes or No
Yes >> GO TO 4.
No >> GO TO 7.
4. CHECK INJECTOR
Does each injector make an operating sound at idle?
Yes or No
Yes >> GO TO 5.
No >> Check injector(s) and circuit(s). Refer to EC-631,
"INJECTOR CIRCUIT" .
PBIB0133E
BBIA0374E
PBIB1986E
EC-274
Revision: October 2005
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
2005 QX56
5. CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be
checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
● Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
● It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 9.
NG >> GO TO 6.
6. CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 7.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-619, "
IGNITION SIGNAL" .
Spark should be generated.
BBIA0380E
PBIB2325E
Spark should be generated.
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
EC-275
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7. CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to EM-27, "
SPARK PLUG (PLATI-
NUM-TIPPED TYPE)" .
NG >> 1. Repair or clean spark plug.
2. GO TO 8.
8. CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded portion.
OK or NG
OK >> INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to MA-18, "
Changing
Spark Plugs" .
9. CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-58, "
CHECKING COMPRESSION PRESSURE" .
OK or NG
OK >> GO TO 10.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10. CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-94, "
FUEL PRESSURE CHECK" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11. DETECT MALFUNCTIONING PART
Check the following.
● Fuel pump and circuit (Refer to EC-637, "FUEL PUMP CIRCUIT" .)
● Fuel pressure regulator (Refer to EC-94, "FUEL PRESSURE CHECK" .)
● Fuel lines
● Fuel filter for clogging
>> Repair or replace.
SEF156I
Spark should be generated.
At idle: Approximately 350 kPa (3.57 kg/cm
2
, 51 psi)
EC-276
Revision: October 2005
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
2005 QX56
12. CHECK IGNITION TIMING
Check the following items. Refer to EC-72, "
Basic Inspection" .
OK or NG
OK >> GO TO 13.
NG >> Follow the EC-72, "
Basic Inspection" .
Items Specifications
Target idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
EC-277
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13. CHECK A/F SENSOR 1 INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14. CHECK A/F SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 15.
NG >> Replace (malfunctioning) A/F sensor 1.
A/F sensor 1 terminal ECM terminal
Bank 1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
BBIA0376E
EC-278
Revision: October 2005
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
2005 QX56
15. CHECK MASS AIR FLOW SENSOR
Check mass air flow sensor signal in “DATA MONITOR” mode with CONSULT-II.
With GST
Check mass air flow sensor signal in Service $01 with GST.
OK or NG
OK >> GO TO 16.
NG >> Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or
ground. Refer to EC-174, "
DTC P0101 MAF SENSOR" .
16. CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in EC-104, "
Symptom Matrix Chart" .
OK or NG
OK >> GO TO 17.
NG >> Repair or replace.
17. ERASE THE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.
Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
>> GO TO 18.
18. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
3.0 - 9.0 g·m/sec: at idling
9.0 - 28.0 g·m/sec: at 2,500 rpm
DTC P0327, P0328, P0332, P0333 KS
EC-279
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DTC P0327, P0328, P0332, P0333 KS PFP:22060
Component Description UBS00H3T
The knock sensor is attached to the cylinder block. It senses engine
knocking using a piezoelectric element. A knocking vibration from
the cylinder block is sensed as vibrational pressure. This pressure is
converted into a voltage signal and sent to the ECM.
On Board Diagnosis Logic UBS00H3U
The MIL will not light up for these diagnoses.
DTC Confirmation Procedure UBS00H3V
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and run it for at least 5 seconds at idle speed.
3. If 1st trip DTC is detected, go to EC-281, "
Diagnostic Procedure"
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0021E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0327
0327
(bank 1)
Knock sensor circuit low
input
An excessively low voltage from the sensor
is sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● Knock sensor
P0332
0332
(bank 2)
P0328
0328
(bank 1)
Knock sensor circuit high
input
An excessively high voltage from the sensor
is sent to ECM.
P0333
0333
(bank 2)
SEF058Y
EC-280
Revision: October 2005
DTC P0327, P0328, P0332, P0333 KS
2005 QX56
Wiring Diagram UBS00H3W
BBWA1684E
DTC P0327, P0328, P0332, P0333 KS
EC-281
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H3X
1. CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check resistance between ECM terminals 15, 36 and ground. Refer to Wiring Diagram.
NOTE:
It is necessary to use an ohmmeter which can measure more than 10 MΩ.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 2.
2. CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect knock sensor harness connector.
2. Check harness continuity between ECM terminal 15 and knock
sensor (bank1) terminal 1, ECM terminal 36 and knock sensor
(bank 2) terminal 1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F26, F101
● Harness for open or short between ECM and knock sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK KNOCK SENSOR
Refer to EC-281, "
Diagnostic Procedure" .
OK or NG
OK >> GO TO 5.
NG >> Replace knock sensor.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
15
36
W
W
Knock sensor (bank 1)
Knock sensor (bank 2)
[Engine is running]
● Idle speed
Approximately 2.5V
Resistance: Approximately 532 - 588 kΩ [at 20°C (68°F)]
Continuity should exist.
PBIB0021E
EC-282
Revision: October 2005
DTC P0327, P0328, P0332, P0333 KS
2005 QX56
5. CHECK GROUND CONNECTIONS
Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace ground connections.
6. CHECK KNOCK SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Disconnect knock sensor harness connector.
2. Check harness continuity between knock sensor terminal 2 and ground. Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F26, F101
● Harness connectors F14, E5
● Harness for open or short between knock sensor terminal 2 and ground
>> Repair open circuit or short power in harness or connectors.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
BBIA0354E
Continuity should exist.
DTC P0327, P0328, P0332, P0333 KS
EC-283
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Component Inspection UBS00H3Y
KNOCK SENSOR
Check resistance between knock sensor terminal 1 and ground.
NOTE:
It is necessary to use an ohmmeter which can measure more
than 10 MΩ.
CAUTION:
Do not use any knock sensors that have been dropped or phys-
ically damaged. Use only new ones.
Removal and Installation UBS00H3Z
KNOCK SENSOR
Refer to EM-73, "CYLINDER BLOCK" .
Resistance: Approximately 532 - 588 kΩ [at 20°C (68°F)]
SEF227W
EC-284
Revision: October 2005
DTC P0335 CKP SENSOR (POS)
2005 QX56
DTC P0335 CKP SENSOR (POS) PFP:23731
Component Description UBS00H40
The crankshaft position sensor (POS) is located on the A/T assem-
bly facing the gear teeth (cogs) of the signal plate. It detects the fluc-
tuation of the engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the engine is running, the high and low parts of the teeth
cause the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor
changes.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.
CONSULT-II Reference Value in Data Monitor Mode UBS00H41
Specification data are reference values.
On Board Diagnosis Logic UBS00H42
DTC Confirmation Procedure UBS00H43
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V with igni-
tion switch ON.
PBIB0562E
PBIB2448E
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED
● Run engine and compare CONSULT-II value with the tachometer indication.
Almost the same speed as the
tachometer indication.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0335
0335
Crankshaft position
sensor (POS) circuit
● The crankshaft position sensor (POS) signal
is not detected by the ECM during the first
few seconds of engine cranking.
● The proper pulse signal from the crankshaft
position sensor (POS) is not sent to ECM
while the engine is running.
● The crankshaft position sensor (POS) signal
is not in the normal pattern during engine
running.
● Harness or connectors
(The sensor circuit is open or shorted)
● Crankshaft position sensor (POS)
● Signal plate
DTC P0335 CKP SENSOR (POS)
EC-285
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WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Crank engine for at least 2 seconds and run it for at least 5 sec-
onds at idle speed.
3. If 1st trip DTC is detected, go to EC-287, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
EC-286
Revision: October 2005
DTC P0335 CKP SENSOR (POS)
2005 QX56
Wiring Diagram UBS00H44
BBWA1685E
DTC P0335 CKP SENSOR (POS)
EC-287
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00H45
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
13 O
Crankshaft position sensor
(POS)
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.
1.0 - 2.0V
[Engine is running]
● Engine speed: 2,000 rpm.
1.0 - 2.0V
PBIB1041E
PBIB1042E
BBIA0354E
EC-288
Revision: October 2005
DTC P0335 CKP SENSOR (POS)
2005 QX56
2. CHECK CRANKSHAFT POSITION (CKP) SENSOR (POS) POWER SUPPLY CIRCUIT
1. Disconnect crankshaft position (CKP) sensor (POS) harness
connector.
2. Turn ignition switch ON.
3. Check voltage between CKP sensor (POS) terminal 3 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F32, E2
● Harness for open or short between crankshaft position sensor (POS) and ECM
● Harness for open or short between crankshaft position sensor (POS) and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK CKP SENSOR (POS) GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between CKP sensor (POS) terminal 1 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F32, E2
● Harness for open or short between crankshaft position sensor (POS) and ground
>> Repair open circuit or short to power in harness or connectors.
BBIA0367E
Voltage: Battery voltage
SEF481Y
Continuity should exist.
DTC P0335 CKP SENSOR (POS)
EC-289
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6. CHECK CKP SENSOR (POS) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 13 and CKP sensor (POS) terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK CRANKSHAFT POSITION SENSOR (POS)
Refer to EC-290, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace crankshaft position sensor (POS).
8. CHECK GEAR TOOTH
Visually check for chipping signal plate gear tooth.
OK or NG
OK >> GO TO 9.
NG >> Replace the signal plate.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
EC-290
Revision: October 2005
DTC P0335 CKP SENSOR (POS)
2005 QX56
Component Inspection UBS00H46
CRANKSHAFT POSITION SENSOR (POS)
1. Loosen the fixing bolt of the sensor.
2. Disconnect crankshaft position sensor (POS) harness connector.
3. Remove the sensor.
4. Visually check the sensor for chipping.
5. Check resistance as shown in the figure.
Removal and Installation UBS00H47
CRANKSHAFT POSITION SENSOR (POS)
Refer to AT-244, "TRANSMISSION ASSEMBLY" .
PBIB0563E
Terminal No. (Polarity) Resistance Ω [at 25°C (77°F)]
1 (+) - 2 (-)
Except 0 or ∞1 (+) - 3 (-)
2 (+) - 3 (-)
PBIB0564E
DTC P0340 CMP SENSOR (PHASE)
EC-291
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DTC P0340 CMP SENSOR (PHASE) PFP:23731
Component Description UBS00H48
The camshaft position sensor (PHASE) senses the protrusion of
exhaust valve cam sprocket to identify a particular cylinder. The
camshaft position sensor (PHASE) senses the piston position.
When the crankshaft position sensor (POS) system becomes inoper-
ative, the camshaft position sensor (PHASE) provides various con-
trols of engine parts instead, utilizing timing of cylinder identification
signals.
The sensor consists of a permanent magnet and Hall IC.
When engine is running, the high and low parts of the teeth cause
the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor changes.
ECM receives the signals as shown in the figure.
On Board Diagnosis Logic UBS00H49
DTC Confirmation Procedure UBS00H4A
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V with igni-
tion switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
PBIB0562E
PBIB2448E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0340
0340
Camshaft position sen-
sor (PHASE) circuit
● The cylinder No. signal is not sent to ECM
for the first few seconds during engine
cranking.
● The cylinder No. signal is not sent to ECM
during engine running.
● The cylinder No. signal is not in the normal
pattern during engine running.
● Harness or connectors
(The sensor circuit is open or shorted)
● Camshaft position sensor (PHASE)
● Camshaft (Exhaust)
● Starter motor (Refer to SC-10, "START-
ING SYSTEM" .)
● Starting system circuit (Refer to SC-10,
"STARTING SYSTEM" .)
● Dead (Weak) battery
EC-292
Revision: October 2005
DTC P0340 CMP SENSOR (PHASE)
2005 QX56
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Crank engine for at least 2 seconds and run it for at least 5 sec-
onds at idle speed.
4. If 1st trip DTC is detected, go to EC-294, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to next step.
5. Maintaining engine speed at more than 800 rpm for at least 5
seconds.
6. If 1st trip DTC is detected, go to EC-294, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P0340 CMP SENSOR (PHASE)
EC-293
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H4B
BBWA1686E
EC-294
Revision: October 2005
DTC P0340 CMP SENSOR (PHASE)
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00H4C
1. CHECK STARTING SYSTEM
Turn ignition switch to START position.
Yes or No
Yes >> GO TO 2.
No >> Check starting system. (Refer to SC-10, "
STARTING SYSTEM" .)
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
14 Y
Camshaft position sensor
(PHASE)
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.
1.0 - 4.0V
[Engine is running]
● Engine speed: 2,000 rpm.
1.0 - 4.0V
PBIB1039E
PBIB1040E
Does the engine turn over?
Does the starter motor operate?
BBIA0354E
DTC P0340 CMP SENSOR (PHASE)
EC-295
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3. CHECK CAMSHAFT POSITION (CMP) SENSOR (PHASE) POWER SUPPLY CIRCUIT
1. Disconnect camshaft position (CMP) sensor (PHASE) harness
connector.
2. Turn ignition switch ON.
3. Check voltage between CMP sensor (PHASE) terminal 3 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F32, E2
● Harness for open or short between camshaft position sensor (PHASE) and ECM
● Harness for open or short between camshaft position sensor (PHASE) and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK CMP SENSOR (PHASE) GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between CMP sensor (PHASE) terminal 1 and ground.
Refer to wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F32, E2
● Harness for open or short between CMP sensor (PHASE) and ground
>> Repair open circuit or short to power in harness or connectors.
BBIA0372E
Voltage: Battery voltage
SEF481Y
Continuity should exist.
EC-296
Revision: October 2005
DTC P0340 CMP SENSOR (PHASE)
2005 QX56
7. CHECK CMP SENSOR (PHASE) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 14 and CMP sensor (PHASE) terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK CAMSHAFT POSITION SENSOR (PHASE)
Refer to EC-297, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace camshaft position sensor (PHASE).
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
DTC P0340 CMP SENSOR (PHASE)
EC-297
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Component Inspection UBS00H4D
CAMSHAFT POSITION SENSOR (PHASE)
1. Loosen the fixing bolt of the sensor.
2. Disconnect camshaft position sensor (PHASE) harness connector.
3. Remove the sensor.
4. Visually check the sensor for chipping.
5. Check resistance as shown in the figure.
Removal and Installation UBS00H4E
CAMSHAFT POSITION SENSOR (PHASE)
Refer to EM-43, "CAMSHAFT" .
PBIB0563E
Terminal No. (Polarity) Resistance Ω [at 25°C (77°F)]
3(+) - 1 (-)
Except 0 or ∞2 (+) - 1 (-)
3 (+) - 2 (-)
PBIB0564E
EC-298
Revision: October 2005
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
2005 QX56
DTC P0420, P0430 THREE WAY CATALYST FUNCTION PFP:20905
On Board Diagnosis Logic UBS00H4F
The ECM monitors the switching frequency ratio of air fuel sensor
(A/F) sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation Procedure UBS00H4G
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70°C
(158°F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70°C (158°F).
7. Open engine hood.
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1)
Catalyst system effi-
ciency below threshold
● Three way catalyst (manifold) does not oper-
ate properly.
● Three way catalyst (manifold) does not have
enough oxygen storage capacity.
● Three way catalyst (manifold)
● Exhaust tube
● Intake air leaks
● Fuel injector
● Fuel injector leaks
● Spark plug
● Improper ignition timing
P0430
0430
(Bank 2)
SEF189Y
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-299
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8. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUP-
PORT” mode with CONSULT-II.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecu-
tive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.
10. Wait 5 seconds at idle.
11. Rev engine up to 2,000 to 3,000 rpm and maintain it until
“INCMP” of “CATALYST” changes to “CMPLT” (It will take
approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70°C
(158°F) and then retest from step 1.
12. Select “SELF-DIAG RESULTS” mode with CONSULT-II.
13. Confirm that the 1st trip DTC is not detected.
If the 1st trip DTC is detected, go to EC-300, "
Diagnostic Proce-
dure" .
Overall Function Check UBS00H4H
Use this procedure to check the overall function of the three way catalyst (manifold). During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Set voltmeter probe between ECM terminals ECM terminals 55
[HO2S2 (bank 1) signal], 74 [HO2S2 (bank 2) signal] and
ground.
7. Keep engine speed at 2,500 rpm constant under no load.
8. Make sure that the voltage does not vary for more than 5 sec-
onds.
If the voltage fluctuation cycle takes less than 5 seconds, go to
EC-300, "
Diagnostic Procedure" .
● 1 cycle: 0.6 - 1.0 → 0 - 0.3 → 0.6 - 1.0
PBIB1784E
PBIB1785E
SEF535Z
PBIB2056E
EC-300
Revision: October 2005
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
2005 QX56
Diagnostic Procedure UBS00H4I
1. CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dent.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before the three way catalyst (manifold).
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK IGNITION TIMING
Check the following items. Refer to EC-72, "
Basic Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Follow the EC-72, "
Basic Inspection" .
PBIB1216E
Items Specifications
Target idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5° BTDC (in P or N position)
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-301
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5. CHECK INJECTORS
1. Stop engine and then turn ignition switch ON.
2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42,
44, 63 and ground with CONSULT-II or tester.
Refer to Wiring Diagram for Injectors, EC-632, "
Wiring Diagram"
.
OK or NG
OK >> GO TO 6.
NG >> Perform EC-633, "
Diagnostic Procedure" .
6. CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be
checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
● Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
● It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 10.
NG >> GO TO 7.
Battery voltage should exist.
PBIB1527E
Spark should be generated.
BBIA0380E
PBIB2325E
EC-302
Revision: October 2005
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
2005 QX56
7. CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 8.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-619, "
IGNITION SIGNAL" .
8. CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace spark plug(s) with standard type one(s). For
spark plug type, refer to MA-18, "
Changing Spark Plugs"
.
NG >> 1. Repair or clean spark plug.
2. GO TO 9.
9. CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug
and the grounded portion.
OK or NG
OK >> INSPECTION END
NG >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to MA-18, "
Changing
Spark Plugs" .
10. CHECK INJECTOR
1. Turn ignition switch OFF.
2. Remove injector assembly.
Refer to EM-29, "
FUEL INJECTOR AND FUEL TUBE" .
Keep fuel hose and all injectors connected to injector gallery.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all injector harness connectors disconnected.
5. Turn ignition switch ON.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip.)>>GO TO 11.
NG (Drips.)>>Replace the injector(s) from which fuel is dripping.
Spark should be generated.
SEF156I
Spark should be generated.
EC-304
Revision: October 2005
DTC P0441 EVAP CONTROL SYSTEM
2005 QX56
DTC P0441 EVAP CONTROL SYSTEM PFP:14950
System Description UBS00H4J
NOTE:
If DTC P0441 is displayed with other DTC such as P2122, P2123, P2127, P2128 or P2138, first perform
trouble diagnosis for other DTC.
In this evaporative emission (EVAP) control system, purge flow occurs during non-closed throttle conditions.
Purge volume is related to air intake volume. Under normal purge conditions (non-closed throttle), the EVAP
canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP con-
trol system pressure sensor to intake manifold vacuum.
On Board Diagnosis Logic UBS00H4K
Under normal conditions (non-closed throttle), sensor output voltage indicates if pressure drop and purge flow
are adequate. If not, a malfunction is determined.
DTC Confirmation Procedure UBS00H4L
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
PBIB1026E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0441
0441
EVAP control system
incorrect purge flow
EVAP control system does not operate prop-
erly, EVAP control system has a leak between
intake manifold and EVAP control system pres-
sure sensor.
● EVAP canister purge volume control
solenoid valve stuck closed
● EVAP control system pressure sensor
and the circuit
● Loose, disconnected or improper con-
nection of rubber tube
● Blocked rubber tube
● Cracked EVAP canister
● EVAP canister purge volume control
solenoid valve circuit
● Accelerator pedal position sensor
● Blocked purge port
● EVAP canister vent control valve
DTC P0441 EVAP CONTROL SYSTEM
EC-305
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WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 70 seconds.
4. Select “PURG FLOW P0441” of “EVAPORATIVE SYSTEM” in “DTC CONFIRMATION” mode with CON-
SULT-II.
5. Touch “START”.
If “COMPLETED” is displayed, go to step 7.
6. When the following conditions are met, “TESTING” will be displayed on the CONSULT-II screen. Maintain
the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take at least 35 seconds.)
If “TESTING” is not changed for a long time, retry from step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
306, "Diagnostic Procedure" .
Overall Function Check UBS00H4M
Use this procedure to check the overall monitoring function of the EVAP control system purge flow monitoring.
During this check, a 1st trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine (VDC switch OFF) and warm it up to normal operating temperature.
3. Turn ignition switch OFF, wait at least 10 seconds.
4. Start engine and wait at least 70 seconds.
5. Set voltmeter probes to ECM terminals 32 (EVAP control system
pressure sensor signal) and ground.
6. Check EVAP control system pressure sensor value at idle speed
and note it.
7. Establish and maintain the following conditions for at least 1
minute.
8. Verify that EVAP control system pressure sensor value stays 0.1V less than the value at idle speed (mea-
sured at step 6) for at least 1 second.
Selector lever Suitable position
VHCL SPEED SE 32 - 120 km/h (20 - 75 MPH)
ENG SPEED 500 - 3,000 rpm
B/FUEL SCHDL 1.0 - 12.0 msec
COOLAN TEMP/S 70 - 100°C (158 - 212°F)
PBIB0826E
Air conditioner switch ON
Headlamp switch ON
Rear window defogger switch ON
Engine speed Approx. 3,000 rpm
Gear position Any position other than P, N or R
PBIB1109E
EC-306
Revision: October 2005
DTC P0441 EVAP CONTROL SYSTEM
2005 QX56
9. If NG, go to EC-306, "Diagnostic Procedure" .
Diagnostic Procedure UBS00H4N
1. CHECK EVAP CANISTER
1. Turn ignition switch OFF.
2. Check EVAP canister for cracks.
OK or NG
OK (With CONSULT-II)>>GO TO 2.
OK (Without CONSULT-II)>>GO TO 3.
NG >> Replace EVAP canister.
2. CHECK PURGE FLOW
With CONSULT-II
1. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-33, "
EVAPORATIVE
EMISSION LINE DRAWING" .
2. Start engine and let it idle.
3. Select “PURG VOL CONT/V” in “ACTIVE TEST” mode with CONSULT-II.
4. Rev engine up to 2,000 rpm.
5. Touch “Qd” and “Qu” on CONSULT-II screen to adjust “PURG
VOL CONT/V” opening and check vacuum existence.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
3. CHECK PURGE FLOW
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-33, "
EVAPORATIVE
EMISSION LINE DRAWING" .
4. Start engine and let it idle.
Do not depress accelerator pedal even slightly.
5. Check vacuum gauge indication before 60 seconds passed after starting engine.
6. Revving engine up to 2,000 rpm after 100 seconds passed after starting engine.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
PURG VOL CONT/V Vacuum
100% Should exist.
0% Should not exist.
PBIB1678E
Vacuum should not exist.
Vacuum should exist.
DTC P0441 EVAP CONTROL SYSTEM
EC-307
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4. CHECK EVAP PURGE LINE
1. Turn ignition switch OFF.
2. Check EVAP purge line for improper connection or disconnection.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 5.
NG >> Repair it.
5. CHECK EVAP PURGE HOSE AND PURGE PORT
1. Disconnect purge hoses connected to EVAP service port A and
EVAP canister purge volume control solenoid valve B .
2. Blow air into each hose and EVAP purge port C .
3. Check that air flows freely.
OK or NG
OK (With CONSULT-II)>>GO TO 6.
OK (Without CONSULT-II)>>GO TO 7.
NG >> Repair or clean hoses and/or purge port.
6. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Start engine.
2. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode with
CONSULT-II. Check that engine speed varies according to the
valve opening.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-323, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP canister purge volume control solenoid valve.
SEF367U
SEF368U
PBIB1678E
EC-308
Revision: October 2005
DTC P0441 EVAP CONTROL SYSTEM
2005 QX56
8. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.
OK or NG
OK >> GO TO 9.
NG >> Replace EVAP control system pressure sensor.
9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR FUNCTION
Refer to DTC Confirmation Procedure for DTC P0452 EC-336, "
DTC Confirmation Procedure" , P0453 EC-
342, "DTC Confirmation Procedure" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10. CHECK RUBBER TUBE FOR CLOGGING
1. Disconnect rubber tube connected to EVAP canister vent control valve.
2. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 11.
NG >> Clean the rubber tube using an air blower.
11. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> Replace EVAP canister vent control valve.
12. CHECK EVAP PURGE LINE
Inspect EVAP purge line (pipe and rubber tube). Check for evidence of leaks.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 13.
NG >> Replace it.
13. CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 14.
14. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Water should not exist.
DTC P0442 EVAP CONTROL SYSTEM
EC-309
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Revision: October 2005 2005 QX56
DTC P0442 EVAP CONTROL SYSTEM PFP:14950
On Board Diagnosis Logic UBS00H4O
This diagnosis detects leaks in the EVAP purge line using engine intake manifold vacuum.
If pressure does not increase, the ECM will check for leaks in the line between the fuel tank and EVAP canister
purge volume control solenoid valve, under the following “Vacuum test” conditions.
The EVAP canister vent control valve is closed to shut the EVAP purge line off. The EVAP canister purge vol-
ume control solenoid valve will then be opened to depressurize the EVAP purge line using intake manifold
vacuum. After this occurs, the EVAP canister purge volume control solenoid valve will be closed.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0442
0442
EVAP control system
small leak detected
(negative pressure)
EVAP control system has a leak, EVAP
control system does not operate prop-
erly.
● Incorrect fuel tank vacuum relief valve
● Incorrect fuel filler cap used
● Fuel filler cap remains open or fails to close.
● Foreign matter caught in fuel filler cap.
● Leak is in line between intake manifold and
EVAP canister purge volume control solenoid
valve.
● Foreign matter caught in EVAP canister vent
control valve.
● EVAP canister or fuel tank leaks
● EVAP purge line (pipe and rubber tube) leaks
● EVAP purge line rubber tube bent
● Loose or disconnected rubber tube
● EVAP canister vent control valve and the circuit
● EVAP canister purge volume control solenoid
valve and the circuit
● Fuel tank temperature sensor
● O-ring of EVAP canister vent control valve is
missing or damaged
● EVAP canister is saturated with water
● EVAP control system pressure sensor
● Fuel level sensor and the circuit
● Refueling EVAP vapor cut valve
● ORVR system leaks
PBIB1026E
EC-310
Revision: October 2005
DTC P0442 EVAP CONTROL SYSTEM
2005 QX56
CAUTION:
● Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.
● If the fuel filler cap is not tightened properly, the MIL may come on.
● Use only a genuine NISSAN rubber tube as a replacement.
DTC Confirmation Procedure UBS00H4P
NOTE:
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
TESTING CONDITION:
● Perform “DTC WORK SUPPORT” when the fuel level is between 1/4 and 3/4 full, and vehicle is
placed on flat level surface.
● Always perform test at a temperature of 0 to 30°C (32 to 86°F).
WITH CONSULT-II
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
4. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70°C (32 - 158°F)
INT/A TEMP SE: 0 - 30°C (32 - 86°F)
5. Select “EVAP SML LEAK P0442/P1442” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-II screen, go to
EC-72, "
Basic Inspection" .
6. Make sure that “OK” is displayed.
If “NG” is displayed, refer to EC-311, "
Diagnostic Procedure" .
NOTE:
Make sure that EVAP hoses are connected to EVAP canister
purge volume control solenoid valve properly.
WITH GST
NOTE:
Be sure to read the explanation of EC-59, "
Driving Pattern" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-59, "
Driving Pattern" .
PBIB0829E
SEC763C
DTC P0442 EVAP CONTROL SYSTEM
EC-311
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3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select Service $07 with GST.
– If P0442 is displayed on the screen, go to EC-311, "Diagnostic Procedure" .
– If P0441 is displayed on the screen, go to EC-306, "Diagnostic Procedure" .
Diagnostic Procedure UBS00H4Q
1. CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
2. Check for genuine NISSAN fuel filler cap design.
OK or NG
OK >> GO TO 2.
NG >> Replace with genuine NISSAN fuel filler cap.
2. CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3. CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-35, "
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF915U
EC-312
Revision: October 2005
DTC P0442 EVAP CONTROL SYSTEM
2005 QX56
5. INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter and pres-
sure pump to EVAP service port securely.
NOTE:
Improper installation of the EVAP service port adapter to the EVAP service port may cause leaking.
With CONSULT-II>>GO TO 6.
Without CONSULT-II>>GO TO 7.
BBIA0366E
SEF916U
DTC P0442 EVAP CONTROL SYSTEM
EC-313
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6. CHECK FOR EVAP LEAK
With CONSULT-II
1. Turn ignition switch ON.
2. Select “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode with CONSULT-II.
3. Touch “START” and apply pressure into the EVAP line until the
pressure indicator reaches the middle of the bar graph.
CAUTION:
● Never use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pres-
sure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
PEF917U
SEF200U
EC-314
Revision: October 2005
DTC P0442 EVAP CONTROL SYSTEM
2005 QX56
7. CHECK FOR EVAP LEAK
Without CONSULT-II
1. Turn ignition switch OFF.
2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts
until the end of test.)
3. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg),
then remove pump and EVAP service port adapter.
CAUTION:
● Never use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pressure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details. Refer
to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
8. CHECK EVAP CANISTER VENT CONTROL VALVE
Check the following.
● EVAP canister vent control valve is installed properly.
Refer to EC-36, "
Removal and Installation" .
● EVAP canister vent control valve.
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace EVAP canister vent control valve and O-ring.
BBIA0443E
SEF200U
DTC P0442 EVAP CONTROL SYSTEM
EC-315
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9. CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Does water drain from the EVAP canister?
Yes or No
Yes >> GO TO 10.
No (With CONSULT-II)>>GO TO 12.
No (Without CONSULT-II)>>GO TO 13.
10. CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK (With CONSULT-II)>>GO TO 12.
OK (Without CONSULT-II)>>GO TO 13.
NG >> GO TO 11.
11. DETECT MALFUNCTIONING PART
Check the following.
● EVAP canister for damage
● EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
12. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode.
4. Touch “Qu” on CONSULT-II screen to increase “PURG VOL
CONT/V” opening to 100%.
5. Check vacuum hose for vacuum when revving engine up to
2,000 rpm.
OK or NG
OK >> GO TO 15.
NG >> GO TO 14.
BBIA0351E
PBIB1678E
EC-316
Revision: October 2005
DTC P0442 EVAP CONTROL SYSTEM
2005 QX56
13. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 16.
NG >> GO TO 14.
14. CHECK VACUUM HOSE
Check vacuum hoses for clogging or disconnection. Refer to EC-114, "
Vacuum Hose Drawing" .
OK or NG
OK >> GO TO 15.
NG >> Repair or reconnect the hose.
15. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-323, "
Component Inspection" .
OK or NG
OK >> GO TO 16.
NG >> Replace EVAP canister purge volume control solenoid valve.
16. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-258, "
Component Inspection" .
OK or NG
OK >> GO TO 17.
NG >> Replace fuel level sensor unit.
17. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK >> GO TO 18.
NG >> Replace EVAP control system pressure sensor.
18. CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 19.
NG >> Repair or reconnect the hose.
19. CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 20.
Vacuum should exist.
DTC P0442 EVAP CONTROL SYSTEM
EC-317
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20. CHECK EVAP/ORVR LINE
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-
nection. For location, refer to EC-39, "
ON BOARD REFUELING VAPOR RECOVERY (ORVR)" .
OK or NG
OK >> GO TO 21.
NG >> Repair or replace hoses and tubes.
21. CHECK RECIRCULATION LINE
Check recirculation line between filler neck tube and fuel tank for clogging, kink, cracks, looseness and
improper connection.
OK or NG
OK >> GO TO 22.
NG >> Repair or replace hose, tube or filler neck tube.
22. CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-43, "
Component Inspection" .
OK or NG
OK >> GO TO 23.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
23. CHECK FUEL LEVEL SENSOR
Refer to DI-22, "
Fuel Level Sensor Unit Inspection" .
OK or NG
OK >> GO TO 24.
NG >> Replace fuel level sensor unit.
24. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
EC-318
Revision: October 2005
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
2005 QX56
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
PFP:14920
Description UBS00H4R
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is
determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-II Reference Value in Data Monitor Mode UBS00H4S
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*
1
EVAP canister
purge flow control
EVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1
Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor*
2
Vehicle speed
PBIB2057E
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle
(Accelerator pedal: Not depressed
even slightly, after starting engine)
0%
2,000 rpm —
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-319
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Revision: October 2005 2005 QX56
On Board Diagnosis Logic UBS00H4T
DTC Confirmation Procedure UBS00H4U
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 13 seconds.
4. If 1st trip DTC is detected, go to EC-322, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0444
0444
EVAP canister purge volume
control solenoid valve circuit
open
An excessively low voltage signal is sent
to ECM through the valve
● Harness or connectors
(The solenoid valve circuit is open or
shorted.)
● EVAP canister purge volume control
solenoid valve
P0445
0445
EVAP canister purge volume
control solenoid valve circuit
shorted
An excessively high voltage signal is sent
to ECM through the valve
● Harness or connectors
(The solenoid valve circuit is shorted.)
● EVAP canister purge volume control
solenoid valve
SEF058Y
EC-320
Revision: October 2005
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
2005 QX56
Wiring Diagram UBS00H4V
BBWA1687E
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-321
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
45 L/Y
EVAP canister purge vol-
ume control solenoid valve
[Engine is running]
● Idle speed
● Accelerator pedal: Not depressed even
slightly, after starting engine.
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
● Engine speed: About 2,000 rpm (More than
100 seconds after starting engine).
11 - 14V
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
PBIB0050E
PBIB0051E
EC-322
Revision: October 2005
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
2005 QX56
Diagnostic Procedure UBS00H4W
1. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIR-
CUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve
harness connector.
3. Turn ignition switch ON.
4. Check voltage between EVAP canister purge volume control
solenoid valve terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between EVAP canister purge volume control solenoid valve and IPDM E/R
● Harness for open or short between EVAP canister purge volume control solenoid valve and ECM
>> Repair harness or connectors.
3. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OUTPUT SIGNAL CIR-
CUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 45 and EVAP canister purge volume control solenoid
valve terminal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)>>GO TO 4.
OK (Without CONSULT-II)>>GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0366E
Voltage: Battery voltage
PBIB2245E
Continuity should exist.
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
EC-323
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Revision: October 2005 2005 QX56
4. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine.
3. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode with
CONSULT-II. Check that engine speed varies according to the
valve opening.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-323, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace EVAP canister purge volume control solenoid valve.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H4X
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
Check air passage continuity of EVAP canister purge volume control
solenoid valve under the following conditions.
Without CONSULT-II
Check air passage continuity of EVAP canister purge volume control
solenoid valve under the following conditions.
PBIB1678E
Condition
(PURG VOL CONT/V value)
Air passage continuity
between A and B
100% Yes
0% No
PBIB2058E
Condition
Air passage continuity
between A and B
12V direct current supply between
terminals 1 and 2
Yes
No supply No
PBIB2059E
EC-324
Revision: October 2005
DTC P0444, P0445 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID
VALVE
2005 QX56
Removal and Installation UBS00H4Y
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EM-15, "INTAKE MANIFOLD" .
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-325
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Revision: October 2005 2005 QX56
DTC P0447 EVAP CANISTER VENT CONTROL VALVE PFP:14935
Component Description UBS00H4Z
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
CONSULT-II Reference Value in Data Monitor Mode UBS00H50
Specification data are reference values.
On Board Diagnosis Logic UBS00H51
PBIB1263E
BBIA0443E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V
● Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0447
0447
EVAP canister vent con-
trol valve circuit open
An improper voltage signal is sent to ECM
through EVAP canister vent control valve.
● Harness or connectors
(The valve circuit is open or shorted.)
● EVAP canister vent control valve
EC-326
Revision: October 2005
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2005 QX56
DTC Confirmation Procedure UBS00H52
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait at least 8 seconds.
4. If 1st trip DTC is detected, go to EC-328, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-327
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H53
BBWA1688E
EC-328
Revision: October 2005
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H54
1. INSPECTION START
Do you have CONSULT-II?
Yes or No
Yes >> GO TO 2.
No >> GO TO 3.
2. CHECK EVAP CANISTER VENT CONTROL VALVE CIRCUIT
With CONSULT-II
1. Turn ignition switch OFF and then turn ON.
2. Select “VENT CONTROL/V” in “ACTIVE TEST” mode with CONSULT-II.
3. Touch “ON/OFF” on CONSULT-II screen.
4. Check for operating sound of the valve.
Clicking noise should be heard.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
117 L/Y
EVAP canister vent control
valve
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
PBIB1679E
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-329
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Revision: October 2005 2005 QX56
3. CHECK EVAP CANISTER VENT CONTROL VALVE POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister vent control valve harness connector.
3. Turn ignition switch ON.
4. Check voltage between EVAP canister vent control valve termi-
nal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E41, C1
● IPDM E/R harness connector E119
● Harness for open or short between EVAP canister vent control valve and IPDM E/R
>> Repair harness or connectors.
5. CHECK EVAP CANISTER VENT CONTROL VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 117 and EVAP canister vent control valve terminal 2.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
Voltage: Battery voltage
BBIA0443E
PBIB0152E
Continuity should exist.
EC-330
Revision: October 2005
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
2005 QX56
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E41, C1
● Harness for open or short between EVAP canister vent control valve and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK RUBBER TUBE FOR CLOGGING
1. Disconnect rubber tube connected to EVAP canister vent control valve.
2. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 8.
NG >> Clean the rubber tube using an air blower.
8. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace EVAP canister vent control valve.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H55
EVAP CANISTER VENT CONTROL VALVE
With CONSULT-II
1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
3. Reconnect harness connectors disconnected.
4. Turn ignition switch ON.
5. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
6. Check air passage continuity and operation delay time.
Make sure new O-ring is installed properly.
Operation takes less than 1 second.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
PBIB1033E
Condition VENT CONTROL/V Air passage continuity between A and B
ON No
OFF Yes
PBIB1679E
DTC P0447 EVAP CANISTER VENT CONTROL VALVE
EC-331
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Revision: October 2005 2005 QX56
7. Clean the air passage (portion A to B ) of EVAP canister vent control valve using an air blower.
8. Perform step 6 again.
Without CONSULT-II
1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
3. Check air passage continuity and operation delay time under the
following conditions.
Make sure new O-ring is installed properly.
Operation takes less than 1 second.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
4. Clean the air passage (portion A to B ) of EVAP canister vent control valve using an air blower.
5. Perform step 3 again.
PBIB1033E
Condition Air passage continuity between A and B
12V direct current supply between
terminals 1 and 2
No
OFF Yes
PBIB1034E
EC-332
Revision: October 2005
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR PFP:22365
Component Description UBS00H56
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
CONSULT-II Reference Value in Data Monitor Mode UBS00H57
Specification data are reference values.
On Board Diagnosis Logic UBS00H58
NOTE:
If DTC P0451 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
BBIA0443E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES
● Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0451
0451
EVAP control system pressure
sensor performance
ECM detects a sloshing signal from the
EVAP control system pressure sensor
● Harness or connectors
● EVAP control system pressure sensor
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-333
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Revision: October 2005 2005 QX56
DTC Confirmation Procedure UBS00H59
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
3. Start engine and wait at least 40 seconds.
NOTE:
Do not depress accelerator pedal even slightly.
If 1st trip DTC is detected, go to EC-333, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00H5A
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
SEF194Y
BBIA0354E
EC-334
Revision: October 2005
DTC P0451 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
2. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR FOR WATER
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check sensor harness connector for water.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness connector.
3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Replace EVAP control system pressure sensor.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
For wiring diagram, refer to EC-337, "
Wiring Diagram" .
>> INSPECTION END
Component Inspection UBS00H5B
EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.
Always replace O-ring with a new one.
2. Install a vacuum pump to EVAP control system pressure sensor.
3. Turn ignition switch ON and check output voltage between ECM
terminal 32 and ground under the following conditions.
CAUTION:
● Always calibrate the vacuum pump gauge when using it.
● Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) or
pressure over 101.3 kPa (760 mmHg, 29.92 inHg).
4. If NG, replace EVAP control system pressure sensor.
Water should not exist.
BBIA0443E
Applied vacuum kPa
(mmHg, inHg)
Voltage V
Not applied 1.8 - 4.8
-26.7 (-200, -7.87) 2.1 to 2.5V lower than above value
PBIB1173E
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-335
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Revision: October 2005 2005 QX56
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR PFP:25085
Component Description UBS00H5C
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
CONSULT-II Reference Value in Data Monitor Mode UBS00H5D
Specification data are reference values.
On Board Diagnosis Logic UBS00H5E
NOTE:
If DTC P0452 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
BBIA0443E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES
● Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0452
0452
EVAP control system pressure
sensor low input
An excessively low voltage from the
sensor is sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● EVAP control system pressure sensor
EC-336
Revision: October 2005
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
DTC Confirmation Procedure UBS00H5F
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. Make sure that “FUEL T/TMP SE” is more than 0°C (32°F).
6. Start engine and wait at least 20 seconds.
If 1st trip DTC is detected, go to EC-338, "
Diagnostic Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Check that voltage between ECM terminal 107 (Fuel tank tem-
perature sensor signal) and ground is less than 4.2V.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and wait at least 20 seconds.
5. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-338, "
Diagnostic Procedure"
.
SEF194Y
PBIB1110E
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-337
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H5G
BBWA1689E
EC-338
Revision: October 2005
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H5H
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check sensor harness connector for water.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness connector.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
32 L
EVAP control system pressure
sensor
[Ignition switch: ON] Approximately 1.8 - 4.8V
48 SB
Sensor power supply
(EVAP control system pressure
sensor)
[Ignition switch: ON] Approximately 5V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
BBIA0354E
Water should not exist.
BBIA0443E
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-339
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Revision: October 2005 2005 QX56
3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between EVAP control system pressure sensor
terminal 3 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E5, F14
● Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between EVAP control system pressure sensor terminal 1 and ECM terminal
67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E5, F14
● Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
Voltage: Approximately 5V
SEF079U
Continuity should exist.
EC-340
Revision: October 2005
DTC P0452 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Check harness continuity between ECM terminal 32 and EVAP control system pressure sensor terminal
2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E5, F14
● Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-340, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP control system pressure sensor.
10. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H5I
EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.
Always replace O-ring with a new one.
2. Install a vacuum pump to EVAP control system pressure sensor.
3. Turn ignition switch ON and check output voltage between ECM
terminal 32 and ground under the following conditions.
CAUTION:
● Always calibrate the vacuum pump gauge when using it.
● Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) or
pressure over 101.3 kPa (760 mmHg, 29.92 inHg).
4. If NG, replace EVAP control system pressure sensor.
Continuity should exist.
Applied vacuum kPa
(mmHg, inHg)
Voltage V
Not applied 1.8 - 4.8
-26.7 (-200, -7.87) 2.1 to 2.5V lower than above value
PBIB1173E
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-341
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DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR PFP:25085
Component Description UBS00H5J
The EVAP control system pressure sensor detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
CONSULT-II Reference Value in Data Monitor Mode UBS00H5K
Specification data are reference values.
On Board Diagnosis Logic UBS00H5L
NOTE:
If DTC P0453 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
BBIA0443E
PBIB1207E
MONITOR ITEM CONDITION SPECIFICATION
EVAP SYS PRES
● Ignition switch: ON Approx. 1.8 - 4.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0453
0453
EVAP control system pressure
sensor high input
An excessively high voltage from the
sensor is sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted.)
● EVAP control system pressure sensor
● EVAP canister vent control valve
● EVAP canister
● Rubber hose from EVAP canister vent
control valve to vehicle frame
EC-342
Revision: October 2005
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
DTC Confirmation Procedure UBS00H5M
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. Make sure that “FUEL T/TMP SE” is more than 0°C (32°F).
6. Start engine and wait at least 20 seconds.
7. If 1st trip DTC is detected, go to EC-344, "
Diagnostic Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Check that voltage between ECM terminal 107 (Fuel tank tem-
perature sensor signal) and ground is less than 4.2V.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and wait at least 20 seconds.
5. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-344, "
Diagnostic Procedure"
.
SEF194Y
PBIB1110E
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-343
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Wiring Diagram UBS00H5N
BBWA1689E
EC-344
Revision: October 2005
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H5O
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check sensor harness connector for water.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness connector.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
32 L
EVAP control system pressure
sensor
[Ignition switch: ON] Approximately 1.8 - 4.8V
48 SB
Sensor power supply
(EVAP control system pressure
sensor)
[Ignition switch: ON] Approximately 5V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
BBIA0354E
Water should not exist.
BBIA0443E
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-345
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3. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between EVAP control system pressure sensor
terminal 3 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E5, F14
● Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between EVAP control system pressure sensor terminal 1 and ECM terminal
67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E5, F14
● Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
Voltage: Approximately 5V
SEF079U
Continuity should exist.
EC-346
Revision: October 2005
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND
SHORT
1. Check harness continuity between ECM terminal 32 and EVAP control system pressure sensor terminal
2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors C1, E41
● Harness connectors E5, F14
● Harness for open or short between EVAP control system pressure sensor and ECM
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK RUBBER TUBE
1. Disconnect rubber tube connected to EVAP canister vent control valve.
2. Check the rubber tube for clogging, vent or kinked.
OK or NG
OK >> GO TO 10.
NG >> Clean the rubber tube using an air blower, repair or replace rubber tube.
10. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace EVAP canister vent control valve.
11. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-348, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> Replace EVAP control system pressure sensor.
Continuity should exist.
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
EC-347
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12. CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Check if water will drain from the EVAP canister.
Yes or No
Yes >> GO TO 13.
No >> GO TO 15.
13. CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 15.
NG >> GO TO 14.
14. DETECT MALFUNCTIONING PART
Check the following.
● EVAP canister for damage
● EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
15. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
BBIA0351E
EC-348
Revision: October 2005
DTC P0453 EVAP CONTROL SYSTEM PRESSURE SENSOR
2005 QX56
Component Inspection UBS00H5P
EVAP CONTROL SYSTEM PRESSURE SENSOR
1. Remove EVAP control system pressure sensor with its harness connector connected from EVAP canister.
Always replace O-ring with a new one.
2. Install a vacuum pump to EVAP control system pressure sensor.
3. Turn ignition switch ON and check output voltage between ECM
terminal 32 and ground under the following conditions.
CAUTION:
● Always calibrate the vacuum pump gauge when using it.
● Do not apply below -93.3 kPa (-700 mmHg, -27.56 inHg) or
pressure over 101.3 kPa (760 mmHg, 29.92 inHg).
4. If NG, replace EVAP control system pressure sensor.
Applied vacuum kPa
(mmHg, inHg)
Voltage V
Not applied 1.8 - 4.8
-26.7 (-200, -7.87) 2.1 to 2.5V lower than above value
PBIB1173E
DTC P0455 EVAP CONTROL SYSTEM
EC-349
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DTC P0455 EVAP CONTROL SYSTEM PFP:14950
On Board Diagnosis Logic UBS00H5Q
This diagnosis detects a very large leak (fuel filler cap fell off etc.) in EVAP system between the fuel tank and
EVAP canister purge volume control solenoid valve.
CAUTION:
● Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.
● If the fuel filler cap is not tightened properly, the MIL may come on.
● Use only a genuine NISSAN rubber tube as a replacement.
PBIB1026E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0455
0455
EVAP control system
gross leak detected
EVAP control system has a very large leak
such as fuel filler cap fell off, EVAP control
system does not operate properly.
● Fuel filler cap remains open or fails to
close.
● Incorrect fuel tank vacuum relief valve
● Incorrect fuel filler cap used
● Foreign matter caught in fuel filler cap.
● Leak is in line between intake manifold and
EVAP canister purge volume control sole-
noid valve.
● Foreign matter caught in EVAP canister
vent control valve.
● EVAP canister or fuel tank leaks
● EVAP purge line (pipe and rubber tube)
leaks
● EVAP purge line rubber tube bent.
● Loose or disconnected rubber tube
● EVAP canister vent control valve and the
circuit
● EVAP canister purge volume control sole-
noid valve and the circuit
● Fuel tank temperature sensor
● O-ring of EVAP canister vent control valve
is missing or damaged.
● EVAP control system pressure sensor
● Refueling EVAP vapor cut valve
● ORVR system leaks
EC-350
Revision: October 2005
DTC P0455 EVAP CONTROL SYSTEM
2005 QX56
DTC Confirmation Procedure UBS00H5R
CAUTION:
Never remove fuel filler cap during the DTC Confirmation Procedure.
NOTE:
● Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid valve
properly.
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
TESTING CONDITION:
● Perform “DTC WORK SUPPORT” when the fuel level is between 1/4 and 3/4 full, and vehicle is
placed on flat level surface.
● Open engine hood before conducting the following procedures.
WITH CONSULT-II
1. Tighten fuel filler cap securely until ratcheting sound is heard.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
5. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70°C (32 - 158°F)
INT/A TEMP SE: 0 - 60°C (32 - 140°F)
6. Select “EVAP SML LEAK P0442/P1442” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-II screen, go to
EC-72, "
Basic Inspection" .
7. Make sure that “OK” is displayed.
If “NG” is displayed, select “SELF-DIAG RESULTS” mode and
make sure that “EVAP GROSS LEAK [P0455]” is displayed. If it
is displayed, refer to EC-351, "
Diagnostic Procedure" .
If P0442 is displayed, perform Diagnostic Procedure for DTC
P0442 EC-311, "
Diagnostic Procedure" .
PBIB0829E
SEC763C
DTC P0455 EVAP CONTROL SYSTEM
EC-351
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WITH GST
NOTE:
Be sure to read the explanation of EC-59, "
Driving Pattern" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-59, "
Driving Pattern" .
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select Service $07 with GST.
● If P0455 is displayed on the screen, go to EC-351, "Diagnostic Procedure" .
● If P0442 is displayed on the screen, go to EC-311, "Diagnostic Procedure" .
● If P0441 is displayed on the screen, go to EC-306, "Diagnostic Procedure" .
Diagnostic Procedure UBS00H5S
1. CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
2. Check for genuine NISSAN fuel filler cap design.
OK or NG
OK >> GO TO 2.
NG >> Replace with genuine NISSAN fuel filler cap.
2. CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3. CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-35, "
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF915U
EC-352
Revision: October 2005
DTC P0455 EVAP CONTROL SYSTEM
2005 QX56
5. CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks, improper connection or
disconnection.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 6.
NG >> Repair or reconnect the hose.
6. CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 7.
7. CHECK EVAP CANISTER VENT CONTROL VALVE
Check the following.
● EVAP canister vent control valve is installed properly.
Refer to EC-36, "
Removal and Installation" .
● EVAP canister vent control valve.
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace EVAP canister vent control valve and O-ring.
8. INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter and pres-
sure pump to EVAP service port securely.
NOTE:
Improper installation of the EVAP service port adapter to the
EVAP service port may cause leaking.
With CONSULT-II>>GO TO 9.
Without CONSULT-II>>GO TO 10.
BBIA0366E
SEF916U
DTC P0455 EVAP CONTROL SYSTEM
EC-353
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9. CHECK FOR EVAP LEAK
With CONSULT-II
1. Turn ignition switch ON.
2. Select “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode
with CONSULT-II.
3. Touch “START” and apply pressure into the EVAP line until the
pressure indicator reaches the middle of the bar graph.
CAUTION:
● Do not use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pres-
sure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
PEF917U
SEF200U
EC-354
Revision: October 2005
DTC P0455 EVAP CONTROL SYSTEM
2005 QX56
10. CHECK FOR EVAP LEAK
Without CONSULT-II
1. Turn ignition switch OFF.
2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts
until the end of test.)
3. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg),
then remove pump and EVAP service port adapter.
CAUTION:
● Do not use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pressure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details. Refer
to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 12.
NG >> Repair or replace.
11. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode.
4. Touch “Qu” on CONSULT-II screen to increase “PURG VOL
CONT/V” opening to 100%.
5. Check vacuum hose for vacuum when revving engine up to
2,000 rpm.
OK or NG
OK >> GO TO 14.
NG >> GO TO 13.
BBIA0443E
SEF200U
PBIB1678E
DTC P0455 EVAP CONTROL SYSTEM
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12. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13. CHECK VACUUM HOSE
Check vacuum hoses for clogging or disconnection. Refer to EC-114, "
Vacuum Hose Drawing" .
OK or NG
OK (With CONSULT-II)>>GO TO 14.
OK (Without CONSULT-II)>>GO TO 15.
NG >> Repair or reconnect the hose.
14. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Start engine.
2. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode with
CONSULT-II. Check that engine speed varies according to the
valve opening.
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-323, "
Component Inspection" .
OK or NG
OK >> GO TO 16.
NG >> Replace EVAP canister purge volume control solenoid valve.
16. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-258, "
Component Inspection" .
OK or NG
OK >> GO TO 17.
NG >> Replace fuel level sensor unit.
Vacuum should exist.
PBIB1678E
EC-356
Revision: October 2005
DTC P0455 EVAP CONTROL SYSTEM
2005 QX56
17. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK >> GO TO 18.
NG >> Replace EVAP control system pressure sensor.
18. CHECK EVAP/ORVR LINE
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-
nection. For location, refer to EC-39, "
ON BOARD REFUELING VAPOR RECOVERY (ORVR)" .
OK or NG
OK >> GO TO 19.
NG >> Repair or replace hoses and tubes.
19. CHECK RECIRCULATION LINE
Check recirculation line between filler neck tube and fuel tank for clogging, kink, cracks, looseness and
improper connection.
OK or NG
OK >> GO TO 20.
NG >> Repair or replace hose, tube or filler neck tube.
20. CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-43, "
Component Inspection" .
OK or NG
OK >> GO TO 21.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
21. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
DTC P0456 EVAP CONTROL SYSTEM
EC-357
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DTC P0456 EVAP CONTROL SYSTEM PFP:14950
On Board Diagnosis Logic UBS00H5T
This diagnosis detects very small leaks in the EVAP line between fuel tank and EVAP canister purge volume
control solenoid valve, using the intake manifold vacuum in the same way as conventional EVAP small leak
diagnosis.
If ECM judges a leak which corresponds to a very small leak, the very small leak P0456 will be detected.
If ECM judges a leak equivalent to a small leak, EVAP small leak P0442 will be detected.
If ECM judges there are no leaks, the diagnosis will be OK.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0456
0456
Evaporative emission
control system very
small leak (negative
pressure check)
● EVAP system has a very small leak.
● EVAP system does not operate prop-
erly.
● Incorrect fuel tank vacuum relief valve
● Incorrect fuel filler cap used
● Fuel filler cap remains open or fails to close.
● Foreign matter caught in fuel filler cap.
● Leak is in line between intake manifold and EVAP
canister purge volume control solenoid valve.
● Foreign matter caught in EVAP canister vent con-
trol valve.
● EVAP canister or fuel tank leaks
● EVAP purge line (pipe and rubber tube) leaks
● EVAP purge line rubber tube bent
● Loose or disconnected rubber tube
● EVAP canister vent control valve and the circuit
● EVAP canister purge volume control solenoid
valve and the circuit
● Fuel tank temperature sensor
● O-ring of EVAP canister vent control valve is miss-
ing or damaged
● EVAP canister is saturated with water
● EVAP control system pressure sensor
● Refueling EVAP vapor cut valve
● ORVR system leaks
● Fuel level sensor and the circuit
● Foreign matter caught in EVAP canister purge vol-
ume control solenoid valve
PBIB1026E
EC-358
Revision: October 2005
DTC P0456 EVAP CONTROL SYSTEM
2005 QX56
CAUTION:
● Use only a genuine NISSAN fuel filler cap as a replacement. If an incorrect fuel filler cap is used,
the MIL may come on.
● If the fuel filler cap is not tightened properly, the MIL may come on.
● Use only a genuine NISSAN rubber tube as a replacement.
DTC Confirmation Procedure UBS00H5U
NOTE:
● If DTC P0456 is displayed with P0442, first perform trouble diagnosis for DTC P0456.
● After repair, make sure that the hoses and clips are installed properly.
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
TESTING CONDITION:
● Open engine hood before conducting following procedure.
● If any of following conditions are met just before the DTC confirmation procedure, leave the vehi-
cle for more than 1 hour.
– Fuel filler cap is removed.
– Fuel is refilled or drained.
– EVAP component parts is/are removed.
● Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Make sure the following conditions are met.
FUEL LEVEL SE: 0.25 - 1.4V
COOLAN TEMP/S: 0 - 32°C (32 - 90°F)
FUEL T/TMP SE: 0 - 35°C (32 - 95°F)
INT/A TEMP SE: More than 0°C (32°F)
If NG, turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle) or refilling/draining
fuel until the output voltage condition of the “FUEL LEVEL SE” meets within the range above and leave
the vehicle for more than 1 hour. Then start from step 1).
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Select “EVAP V/S LEAK P0456/P1456” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-II.
Follow the instruction displayed.
5. Make sure that “OK” is displayed.
If “NG” is displayed, refer to EC-360, "
Diagnostic Procedure" .
NOTE:
● If the engine speed cannot be maintained within the range displayed on CONSULT-II screen, go
to EC-72, "
Basic Inspection" .
● Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid
valve properly.
PBIB0837E
DTC P0456 EVAP CONTROL SYSTEM
EC-359
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Overall Function Check UBS00H5V
WITH GST
Use this procedure to check the overall function of the EVAP very small leak function. During this check, a 1st
trip DTC might not be confirmed.
CAUTION:
● Do not use compressed air, doing so may damage the EVAP system.
● Do not start engine.
● Do not exceeded 4.12 kPa (0.042 kg/cm
2
, 0.6 psi).
1. Attach the EVAP service port adapter securely to the EVAP ser-
vice port.
2. Set the pressure pump and a hose.
3. Also set a vacuum gauge via 3-way connector and a hose.
4. Turn ignition switch ON.
5. Connect GST and select Service $08.
6. Using Service $08, control the EVAP canister vent control valve
(close).
7. Apply pressure and make sure the following conditions are sat-
isfied.
Pressure to be applied: 2.7 kPa (20 mmHg, 0.79 inHg)
Time to be waited after the pressure drawn in to the EVAP
system and the pressure to be dropped: 60 seconds and
the pressure should not be dropped more than 0.4 kPa (3 mmHg, 0.12 inHg).
If NG, go to EC-360, "
Diagnostic Procedure" .
If OK, go to next step.
8. Disconnect GST.
9. Start engine and warm it up to normal operating temperature.
10. Turn ignition switch OFF and wait at least 10 seconds.
11. Restart engine and let it idle for 90 seconds.
12. Keep engine speed at 2,000 rpm for 30 seconds.
13. Turn ignition switch OFF.
NOTE:
For more information, refer to GST Instruction Manual.
BBIA0366E
SEF462UI
EC-360
Revision: October 2005
DTC P0456 EVAP CONTROL SYSTEM
2005 QX56
Diagnostic Procedure UBS00H5W
1. CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
2. Check for genuine NISSAN fuel filler cap design.
OK or NG
OK >> GO TO 2.
NG >> Replace with genuine NISSAN fuel filler cap.
2. CHECK FUEL FILLER CAP INSTALLATION
Check that the cap is tightened properly by rotating the cap clockwise.
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3. CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-35, "
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)" .
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
SEF915U
DTC P0456 EVAP CONTROL SYSTEM
EC-361
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5. INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter and pres-
sure pump to EVAP service port securely.
NOTE:
Improper installation of the EVAP service port adapter to the
EVAP service port may cause leaking.
With CONSULT-II>>GO TO 6.
Without CONSULT-II>>GO TO 7.
6. CHECK FOR EVAP LEAK
With CONSULT-II
1. Turn ignition switch ON.
2. Select “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode with CONSULT-II.
3. Touch “START” and apply pressure into the EVAP line until the
pressure indicator reaches the middle of the bar graph.
CAUTION:
● Do not use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pres-
sure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
BBIA0366E
SEF916U
PEF917U
SEF200U
EC-362
Revision: October 2005
DTC P0456 EVAP CONTROL SYSTEM
2005 QX56
7. CHECK FOR EVAP LEAK
Without CONSULT-II
1. Turn ignition switch OFF.
2. Apply 12 volts DC to EVAP canister vent control valve. The valve will close. (Continue to apply 12 volts
until the end of test.)
3. Pressurize the EVAP line using pressure pump with 1.3 to 2.7 kPa (10 to 20 mmHg, 0.39 to 0.79 inHg),
then remove pump and EVAP service port adapter.
CAUTION:
● Do not use compressed air or a high pressure pump.
● Do not exceed 4.12 kPa (0.042 kg/cm
2
, 0.6 psi) of pressure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak
detector, refer to the instruction manual for more details. Refer
to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace.
8. CHECK EVAP CANISTER VENT CONTROL VALVE
Check the following.
● EVAP canister vent control valve is installed properly.
Refer to EC-36, "
Removal and Installation" .
● EVAP canister vent control valve.
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace EVAP canister vent control valve and O-ring.
BBIA0443E
SEF200U
DTC P0456 EVAP CONTROL SYSTEM
EC-363
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9. CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Does water drain from the EVAP canister?
Yes or No
Yes >> GO TO 10.
No (With CONSULT-II)>>GO TO 12.
No (Without CONSULT-II)>>GO TO 13.
10. CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK (With CONSULT-II)>>GO TO 12.
OK (Without CONSULT-II)>>GO TO 13.
NG >> GO TO 11.
11. DETECT MALFUNCTIONING PART
Check the following.
● EVAP canister for damage
● EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
12. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
With CONSULT-II
1. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
2. Start engine.
3. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode.
4. Touch “Qu” on CONSULT-II screen to increase “PURG VOL
CONT/V” opening to 100%.
5. Check vacuum hose for vacuum when revving engine up to
2,000 rpm.
OK or NG
OK >> GO TO 15.
NG >> GO TO 14.
BBIA0351E
PBIB1678E
EC-364
Revision: October 2005
DTC P0456 EVAP CONTROL SYSTEM
2005 QX56
13. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OPERATION
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose to EVAP canister purge volume control solenoid valve at EVAP service port.
4. Start engine and let it idle for at least 80 seconds.
5. Check vacuum hose for vacuum when revving engine up to 2,000 rpm.
OK or NG
OK >> GO TO 16.
NG >> GO TO 14.
14. CHECK VACUUM HOSE
Check vacuum hoses for clogging or disconnection. Refer to EC-114, "
Vacuum Hose Drawing" .
OK or NG
OK >> GO TO 15.
NG >> Repair or reconnect the hose.
15. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-323, "
Component Inspection" .
OK or NG
OK >> GO TO 16.
NG >> Replace EVAP canister purge volume control solenoid valve.
16. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-258, "
Component Inspection" .
OK or NG
OK >> GO TO 17.
NG >> Replace fuel level sensor unit.
17. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-330, "
Component Inspection" .
OK or NG
OK >> GO TO 18.
NG >> Replace EVAP control system pressure sensor.
18. CHECK EVAP PURGE LINE
Check EVAP purge line (pipe, rubber tube, fuel tank and EVAP canister) for cracks or improper connection.
Refer to EC-33, "
EVAPORATIVE EMISSION LINE DRAWING" .
OK or NG
OK >> GO TO 19.
NG >> Repair or reconnect the hose.
19. CLEAN EVAP PURGE LINE
Clean EVAP purge line (pipe and rubber tube) using air blower.
>> GO TO 20.
Vacuum should exist.
DTC P0456 EVAP CONTROL SYSTEM
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20. CHECK EVAP/ORVR LINE
Check EVAP/ORVR line between EVAP canister and fuel tank for clogging, kink, looseness and improper con-
nection. For location, refer to EC-39, "
ON BOARD REFUELING VAPOR RECOVERY (ORVR)" .
OK or NG
OK >> GO TO 21.
NG >> Repair or replace hoses and tubes.
21. CHECK RECIRCULATION LINE
Check recirculation line between filler neck tube and fuel tank for clogging, kink, cracks, looseness and
improper connection.
OK or NG
OK >> GO TO 22.
NG >> Repair or replace hose, tube or filler neck tube.
22. CHECK REFUELING EVAP VAPOR CUT VALVE
Refer to EC-43, "
Component Inspection" .
OK or NG
OK >> GO TO 23.
NG >> Replace refueling EVAP vapor cut valve with fuel tank.
23. CHECK FUEL LEVEL SENSOR
Refer to DI-22, "
Fuel Level Sensor Unit Inspection" .
OK or NG
OK >> GO TO 24.
NG >> Replace fuel level sensor unit.
24. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
EC-366
Revision: October 2005
DTC P0460 FUEL LEVEL SENSOR
2005 QX56
DTC P0460 FUEL LEVEL SENSOR PFP:25060
Component Description UBS00H5X
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis Logic UBS00H5Y
NOTE:
If DTC P0460 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
When the vehicle is parked, naturally the fuel level in the fuel tank is stable. It means that output signal of the
fuel level sensor does not change. If ECM senses sloshing signal from the sensor, fuel level sensor malfunc-
tion is detected.
DTC Confirmation Procedure UBS00H5Z
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait maximum of 2 consecutive minutes.
4. If 1st trip DTC is detected, go to EC-367, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0460
0460
Fuel level sensor circuit
noise
Even though the vehicle is parked, a signal
being varied is sent from the fuel level sensor
to ECM.
● Harness or connectors
(The CAN communication line is open or
shorted)
● Harness or connectors
(The sensor circuit is open or shorted)
● Combination meter
● Fuel level sensor
SEF195Y
DTC P0460 FUEL LEVEL SENSOR
EC-367
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Diagnostic Procedure UBS00H60
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Removal and Installation UBS00H61
FUEL LEVEL SENSOR
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
EC-368
Revision: October 2005
DTC P0461 FUEL LEVEL SENSOR
2005 QX56
DTC P0461 FUEL LEVEL SENSOR PFP:25060
Component Description UBS00H62
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis Logic UBS00H63
NOTE:
If DTC P0461 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Driving long distances naturally affect fuel gauge level.
This diagnosis detects the fuel gauge malfunction of the gauge not moving even after a long distance has
been driven.
Overall Function Check UBS00H64
Use this procedure to check the overall function of the fuel level sensor function. During this check, a 1st trip
DTC might not be confirmed.
WARNING:
When performing following procedure, be sure to observe the handling of the fuel. Refer to FL-9,
"FUEL TANK" .
TESTING CONDITION:
Before starting overall function check, preparation of draining fuel and refilling fuel is required.
WITH CONSULT-II
NOTE:
Start from step 10, if it is possible to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/
8 Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line, refer to EC-93, "
FUEL PRESSURE RELEASE" .
3. Remove the fuel feed hose on the fuel level sensor unit.
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch OFF and wait at least 10 seconds then turn ON.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0461
0461
Fuel level sensor circuit
range/performance
The output signal of the fuel level sensor
does not change within the specified range
even though the vehicle has been driven a
long distance.
● Harness or connectors
(The CAN communication line is open or
shorted)
● Harness or connectors
(The sensor circuit is open or shorted)
● Combination meter
● Fuel level sensor
DTC P0461 FUEL LEVEL SENSOR
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6. Select “FUEL LEVEL SE” in “DATA MONITOR” mode with CON-
SULT-II.
7. Check “FUEL LEVEL SE” output voltage and note it.
8. Select “FUEL PUMP” in “ACTIVE TEST” mode with CONSULT-
II.
9. Touch “ON” and drain fuel approximately 30 (7-7/8 US gal, 6-
5/8 Imp gal) and stop it.
10. Check “FUEL LEVEL SE” output voltage and note it.
11. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
12. Check “FUEL LEVEL SE” output voltage and note it.
13. Confirm whether the voltage changes more than 0.03V during step 7 to 10 and 10 to 12.
If NG, go to EC-369, "
Diagnostic Procedure" .
WITH GST
NOTE:
Start from step 8, if it is possible to confirm that the fuel cannot be drained by 30 (7-7/8 US gal, 6-5/8
Imp gal) in advance.
1. Prepare a fuel container and a spare hose.
2. Release fuel pressure from fuel line. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
3. Remove the fuel feed hose on the fuel level sensor unit.
4. Connect a spare fuel hose where the fuel feed hose was removed.
5. Turn ignition switch ON.
6. Drain fuel by 30 (7-7/8 US gal, 6-5/8 Imp gal) from the fuel tank using proper equipment.
7. Confirm that the fuel gauge indication varies.
8. Fill fuel into the fuel tank for 30 (7-7/8 US gal, 6-5/8 Imp gal).
9. Confirm that the fuel gauge indication varies.
10. If NG, go to EC-369, "
Diagnostic Procedure" .
Diagnostic Procedure UBS00H65
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Removal and Installation UBS00H66
FUEL LEVEL SENSOR
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
SEF195Y
EC-370
Revision: October 2005
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
2005 QX56
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT PFP:25060
Component Description UBS00H67
The fuel level sensor is mounted in the fuel level sensor unit. The
sensor detects a fuel level in the fuel tank and transmits a signal to
the combination meter. The combination meter sends the fuel level
sensor signal to the ECM through CAN communication line.
It consists of two parts, one is mechanical float and the other is vari-
able resistor. Fuel level sensor output voltage changes depending on
the movement of the fuel mechanical float.
On Board Diagnosis Logic UBS00H68
NOTE:
If DTC P0462 or P0463 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for
DTC U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
This diagnosis indicates the former, to detect open or short circuit malfunction.
DTC Confirmation Procedure UBS00H69
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at ignition
switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-371, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0402E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0462
0462
Fuel level sensor circuit
low input
An excessively low voltage from the sensor is
sent to ECM.
● Harness or connectors
(The CAN communication line is open or
shorted)
● Harness or connectors
(The sensor circuit is open or shorted)
● Combination meter
● Fuel level sensor
P0463
0463
Fuel level sensor circuit
high input
An excessively high voltage from the sensor is
sent to ECM.
SEF195Y
DTC P0462, P0463 FUEL LEVEL SENSOR CIRCUIT
EC-371
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Diagnostic Procedure UBS00H6A
1. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Removal and Installation UBS00H6B
FUEL LEVEL SENSOR
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
EC-372
Revision: October 2005
DTC P0500 VSS
2005 QX56
DTC P0500 VSS PFP:32702
Description UBS00H6C
NOTE:
If DTC P0500 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
The vehicle speed signal is sent to the combination meter from the “ABS actuator and electric unit (control
unit)” by CAN communication line. The c combination meter then sends a signal to the ECM by CAN commu-
nication line.
On Board Diagnosis Logic UBS00H6D
DTC Confirmation Procedure UBS00H6E
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Steps 1 and 2 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Read “VHCL SPEED SE” in “DATA MONITOR” mode with CONSULT-II. The vehicle speed on CONSULT-
II should exceed 10 km/h (6 MPH) when rotating wheels with suitable gear position.
If NG, go to EC-373, "
Diagnostic Procedure" .
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Warm engine up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec-
onds.
6. If 1st trip DTC is detected, go to EC-373, "
Diagnostic Procedure"
.
Overall Function Check UBS00H6F
Use this procedure to check the overall function of the vehicle speed sensor circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0500
0500
Vehicle speed sensor
The almost 0 km/h (0 MPH) signal from
vehicle speed sensor is sent to ECM
even when vehicle is being driven.
● Harness or connectors
(The CAN communication line is open or
shorted)
● Harness or connectors
(The vehicle speed signal circuit is open or
shorted)
● Wheel sensor
● Combination meter
● ABS actuator and electric unit (control unit)
ENG SPEED More than 1,600 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL More than 6.9 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
SEF196Y
DTC P0500 VSS
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2. Start engine.
3. Read vehicle speed sensor signal in Service $01 with GST.
The vehicle speed sensor on GST should be able to exceed 10 km/h (6 MPH) when rotating wheels with
suitable gear position.
4. If NG, go to EC-373, "
Diagnostic Procedure" .
Diagnostic Procedure UBS00H6G
1. CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
>> INSPECTION END
EC-374
Revision: October 2005
DTC P0506 ISC SYSTEM
2005 QX56
DTC P0506 ISC SYSTEM PFP:23781
Description UBS00H6H
NOTE:
If DTC P0506 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis Logic UBS00H6I
DTC Confirmation Procedure UBS00H6J
NOTE:
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
● If the target idle speed is out of the specified value, perform EC-91, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-669,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:
● Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
● Always perform the test at a temperature above −10°C (14°F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-375, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0506
0506
Idle speed control system
RPM lower than expected
The idle speed is less than the target idle
speed by 100 rpm or more.
● Electric throttle control actuator
● Intake air leak
SEF174Y
DTC P0506 ISC SYSTEM
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Diagnostic Procedure UBS00H6K
1. CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 2.
NG >> Discover air leak location and repair.
2. REPLACE ECM
1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
4. Perform EC-90, "
VIN Registration" .
5. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-90, "
Throttle Valve Closed Position Learning" .
7. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
EC-376
Revision: October 2005
DTC P0507 ISC SYSTEM
2005 QX56
DTC P0507 ISC SYSTEM PFP:23781
Description UBS00H6L
NOTE:
If DTC P0507 is displayed with other DTC, first perform the trouble diagnosis for the other DTC.
The ECM controls the engine idle speed to a specified level through the fine adjustment of the air, which is let
into the intake manifold, by operating the electric throttle control actuator. The operating of the throttle valve is
varied to allow for optimum control of the engine idling speed. The crankshaft position sensor (POS) detects
the actual engine speed and sends a signal to the ECM.
The ECM controls the electric throttle control actuator so that the engine speed coincides with the target value
memorized in the ECM. The target engine speed is the lowest speed at which the engine can operate steadily.
The optimum value stored in the ECM is determined by taking into consideration various engine conditions,
such as during warming up, deceleration, and engine load (air conditioner, power steering and cooling fan
operation, etc.).
On Board Diagnosis Logic UBS00H6M
DTC Confirmation Procedure UBS00H6N
NOTE:
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
● If the target idle speed is out of the specified value, perform EC-91, "Idle Air Volume Learning" ,
before conducting DTC Confirmation Procedure. For the target idle speed, refer to the EC-669,
"SERVICE DATA AND SPECIFICATIONS (SDS)" .
TESTING CONDITION:
● Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
● Always perform the test at a temperature above −10°C (14°F).
WITH CONSULT-II
1. Open engine hood.
2. Start engine and warm it up to normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON again and select “DATA MONITOR”
mode with CONSULT-II.
5. Start engine and run it for at least 1 minute at idle speed.
6. If 1st trip DTC is detected, go to EC-377, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0507
0507
Idle speed control system
RPM higher than expected
The idle speed is more than the target idle
speed by 200 rpm or more.
● Electric throttle control actuator
● Intake air leak
● PCV system
SEF174Y
DTC P0507 ISC SYSTEM
EC-377
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Diagnostic Procedure UBS00H6O
1. CHECK PCV HOSE CONNECTION
Confirm that PCV hose is connected correctly.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK INTAKE AIR LEAK
1. Start engine and let it idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Discover air leak location and repair.
3. REPLACE ECM
1. Stop engine.
2. Replace ECM.
3. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
4. Perform EC-90, "
VIN Registration" .
5. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-90, "
Throttle Valve Closed Position Learning" .
7. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
EC-378
Revision: October 2005
DTC P0550 PSP SENSOR
2005 QX56
DTC P0550 PSP SENSOR PFP:49763
Component Description UBS00H6P
Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor Mode UBS00H6Q
Specification data are reference values.
On Board Diagnosis Logic UBS00H6R
The MIL will not light up for this diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
DTC Confirmation Procedure UBS00H6S
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 5 seconds.
4. If 1st trip DTC is detected, go to EC-380, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
BBIA0365E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL
● Engine: After warming up, idle
the engine
Steering wheel: Not being turned
(Forward direction)
OFF
Steering wheel: Being turned ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550
Power steering pressure
sensor circuit
An excessively low or high voltage from the
sensor is sent to ECM.
● Harness or connectors
(The sensor circuit is open or shorted)
● Power steering pressure sensor
SEF058Y
DTC P0550 PSP SENSOR
EC-379
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Wiring Diagram UBS00H6T
BBWA1690E
EC-380
Revision: October 2005
DTC P0550 PSP SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H6U
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
12 R
Power steering pressure
sensor
[Engine is running]
● Steering wheel: Being turned.
0.5 - 4.5V
[Engine is running]
● Steering wheel: Not being turned.
0.4 - 0.8V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
68 W/L
Sensor power supply
(Power steering pressure
sensor)
[Ignition switch: ON] Approximately 5V
BBIA0354E
DTC P0550 PSP SENSOR
EC-381
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2. CHECK PSP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect power steering pressure (PSP) sensor harness con-
nector.
2. Turn ignition switch ON.
3. Check voltage between PSP sensor terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connectors.
3. CHECK PSP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between PSP sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 12 and PSP sensor terminal 2.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK PSP SENSOR
Refer to EC-382, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace PSP sensor.
BBIA0365E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
Continuity should exist.
EC-382
Revision: October 2005
DTC P0550 PSP SENSOR
2005 QX56
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H6V
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 12 and ground under the
following conditions.
Removal and Installation UBS00H6W
POWER STEERING PRESSURE SENSOR
Refer to PS-31, "HYDRAULIC LINE" .
Condition Voltage
Steering wheel: Being turned. 0.5 - 4.5V
Steering wheel: Not being turned. 0.4 - 0.8V
MBIB0126E
DTC P0605 ECM
EC-383
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DTC P0605 ECM PFP:23710
Component Description UBS00H6X
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.
On Board Diagnosis Logic UBS00H6Y
This self-diagnosis has one or two trip detection logic.
FAIL-SAFE MODE
ECM enters fail-safe mode when the malfunction A is detected.
DTC Confirmation Procedure UBS00H6Z
Perform PROCEDURE FOR MALFUNCTION A first. If the 1st trip DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION B. If there is no malfunction on PROCEDURE FOR MALFUNCTION
B, perform PROCEDURE FOR MALFUNCTION C.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A
With CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If 1st trip DTC is detected, go to EC-384, "
Diagnostic Procedure"
With GST
Follow the procedure “With CONSULT-II” above.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0605
0605
Engine control module
A) ECM calculation function is malfunctioning.
● ECMB) ECM EEP-ROM system is malfunctioning.
C) ECM self shut-off function is malfunctioning.
Detected items Engine operation condition in fail-safe mode
Malfunction A
● ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx.
5 degrees) by the return spring.
● ECM deactivates ASCD operation.
SEF058Y
EC-384
Revision: October 2005
DTC P0605 ECM
2005 QX56
PROCEDURE FOR MALFUNCTION B
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
4. If 1st trip DTC is detected, go to EC-384, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION C
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
4. Repeat step 3 for 32 times.
5. If 1st trip DTC is detected, go to EC-384, "
Diagnostic Procedure"
.
With GST
Follow the procedure “With CONSULT-II” above.
Diagnostic Procedure UBS00H70
1. INSPECTION START
With CONSULT-II
1. Turn ignition switch ON.
2. Select “SELF DIAG RESULTS” mode with CONSULT-II.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-383, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P0605 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-383, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P0605 displayed again?
Yes or No
Yes >> GO TO 2.
No >> INSPECTION END
SEF058Y
SEF058Y
DTC P0605 ECM
EC-385
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2. REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
3. Perform EC-90, "
VIN Registration" .
4. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-90, "
Throttle Valve Closed Position Learning" .
6. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
EC-386
Revision: October 2005
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
2005 QX56
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER PFP:22693
Description UBS00H71
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-II Reference Value in Data Monitor Mode UBS00H72
Specification data are reference values.
On Board Diagnosis Logic UBS00H73
DTC Confirmation Procedure UBS00H74
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and let it idle for at least 10 seconds.
3. If 1st trip DTC is detected, go to EC-390, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)
Engine speed
Air fuel ratio (A/F) sensor 1
heater control
Air fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)
● Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1031
1031
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
low
The current amperage in the heated air fuel ratio
(A/F) sensor 1 heater circuit is out of the normal
range.
(An excessively low voltage signal is sent to ECM
through the heated air fuel ratio (A/F) sensor 1
heater.)
● Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
● A/F sensor 1 heater
P1051
1051
(Bank 2)
P1032
1032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high
The current amperage in the heated air fuel ratio
(A/F) sensor 1 heater circuit is out of the normal
range.
(An excessively high voltage signal is sent to ECM
through the heated air fuel ratio (A/F) sensor 1
heater.)
● Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
● A/F sensor 1 heater
P1052
1052
(Bank 2)
SEF058Y
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
EC-387
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Wiring Diagram UBS00H75
BANK 1
BBWA1691E
EC-388
Revision: October 2005
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
TER-
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NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
2O/B
A/F sensor 1 heater
(bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 5V
PBIB1584E
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
EC-389
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BANK 2
BBWA1692E
EC-390
Revision: October 2005
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00H76
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
24 BR/W
A/F sensor 1 heater
(bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 5V
PBIB1584E
BBIA0354E
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
EC-391
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2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4. CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 2 (bank 1) or 24 (bank 2) and A/F sensor 1 terminal 4.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK A/F SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> GO TO 7.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
Continuity should exist.
EC-392
Revision: October 2005
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1 HEATER
2005 QX56
6. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 7.
NG >> Repair or replace.
7. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
Component Inspection UBS00H77
AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Check resistance between terminals 3 and 4.
Check continuity between terminals 3 and 1, 2, 5, 6, terminals 4 and
1, 2, 5, 6.
If NG, replace the A/F sensor 1.
CAUTION:
● Discard any A/F sensor which has been dropped from a
height of more than 0.5 m (19.7 in) onto a hard surface such
as a concrete floor; use a new one.
● Before installing new A/F sensor, clean exhaust system
threads using Heated Oxygen Sensor Thread Cleaner tool
J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and Installation UBS00H78
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
Resistance: 2.3 - 4.3Ω at 25°C (77°F)
Continuity should not exist.
PBIB1684E
DTC P1065 ECM POWER SUPPLY
EC-393
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DTC P1065 ECM POWER SUPPLY PFP:23710
Component Description UBS00H79
Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.
On Board Diagnosis Logic UBS00H7A
DTC Confirmation Procedure UBS00H7B
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
5. Repeat steps 3 and 4 for 4 times.
6. If 1st trip DTC is detected, go to EC-395, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1065
1065
ECM power supply circuit
ECM back-up RAM system does not function
properly.
● Harness or connectors
[ECM power supply (back-up) circuit is
open or shorted.]
● ECM
SEF058Y
EC-394
Revision: October 2005
DTC P1065 ECM POWER SUPPLY
2005 QX56
Wiring Diagram UBS00H7C
BBWA1693E
DTC P1065 ECM POWER SUPPLY
EC-395
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H7D
1. CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check voltage between ECM terminal 121 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.
● IPDM E/R connector E121
● 20A fuse
● Harness for open or short between ECM and battery
>> Repair or replace harness or connectors.
3. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connectors.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
121 W
Power supply for ECM
(Back-up)
[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0026E
EC-396
Revision: October 2005
DTC P1065 ECM POWER SUPPLY
2005 QX56
4. PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-II
1. Turn ignition switch ON.
2. Select “SELF DIAG RESULTS” mode with CONSULT-II.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-393, "DTC Confirmation Procedure" .
5. Is the 1st trip DTC P1065 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-393, "
DTC Confirmation Procedure" .
5. Is the 1st trip DTC P1065 displayed again?
Yes or No
Yes >> GO TO 5.
No >> INSPECTION END
5. REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs. Refer to
BL-139, "
ECM Re-communicating Function" .
3. Perform EC-90, "
VIN Registration" .
4. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-90, "
Throttle Valve Closed Position Learning" .
6. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR
EC-397
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DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR PFP:16119
Component Description UBS00H7E
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throt-
tle valve and feeds the voltage signals to the ECM. The ECM judges the current opening angle of the throttle
valve from these signals and the ECM controls the throttle control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagnosis Logic UBS00H7F
This self-diagnosis has one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure UBS00H7G
NOTE:
● Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION C.
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A AND B
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to P position.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Turn ignition switch ON and wait at least 1 second.
7. Shift selector lever to D position and wait at least 3 seconds.
8. Shift selector lever to P position.
9. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
10. If DTC is detected, go to EC-398, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1121
1121
Electric throttle control
actuator
A)
Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.
● Electric throttle control actuator
B)
Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode
Malfunction A
The ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.
Malfunction B ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.
Malfunction C
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.
SEF058Y
EC-398
Revision: October 2005
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR
2005 QX56
PROCEDURE FOR MALFUNCTION C
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to N, P position.
5. Start engine and let it idle for 3 seconds.
6. If DTC is detected, go to EC-398, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
Diagnostic Procedure UBS00H7H
1. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Remove the intake air duct.
2. Check if a foreign matter is caught between the throttle valve
and the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
2. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
SEF058Y
BBIA0364E
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-399
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DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION PFP:16119
Description UBS00H7I
NOTE:
If DTC P1122 is displayed with DTC P1121 or 1126, first perform the trouble diagnosis for DTC P1121 or
P1126. Refer to EC-397, "
DTC P1121 ELECTRIC THROTTLE CONTROL ACTUATOR" or EC-405, "DTC
P1124, P1126 THROTTLE CONTROL MOTOR RELAY" .
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis Logic UBS00H7J
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure UBS00H7K
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V when engine
is running.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-401, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1122
1122
Electric throttle control
performance problem
Electric throttle control function does not oper-
ate properly.
● Harness or connectors
(Throttle control motor circuit is open or
shorted)
● Electric throttle control actuator
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y
EC-400
Revision: October 2005
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
2005 QX56
Wiring Diagram UBS00H7L
BBWA1694E
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-401
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00H7M
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
3L
Throttle control motor relay
power supply
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
4L/W
Throttle control motor
(Close)
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Released
0 - 14V
5L/B
Throttle control motor
(Open)
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
0 - 14V
104 O Throttle control motor relay
[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
PBIB1104E
PBIB1105E
BBIA0354E
EC-402
Revision: October 2005
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
2005 QX56
2. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-I
1. Check voltage between ECM terminal 3 and ground under the
following conditions with CONSULT-II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 3.
3. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Check voltage between ECM terminal 104 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 4.
4. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E122.
3. Check harness continuity between ECM terminal 104 and IPDM E/R terminal 47.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 8.
NG >> Replace 20A fuse.
Ignition switch Voltage
OFF Approximately 0V
ON
Battery voltage
(11 - 14V)
MBIB0028E
Voltage: Battery voltage
PBIB1171E
Continuity should exist.
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
EC-403
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6. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 3 and IPDM E/R terminal 6.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R. Refer to PG-17, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MOD-
ULE ENGINE ROOM)" .
NG >> Repair or replace harness or connectors.
9. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Turn ignition switch OFF.
2. Disconnect electric throttle control actuator harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair or replace.
Continuity should exist.
Electric throttle control
actuator terminal
ECM terminal Continuity
5
5 Should not exist
4 Should exist
6
5 Should exist
4 Should not exist
PBIB1480E
EC-404
Revision: October 2005
DTC P1122 ELECTRIC THROTTLE CONTROL FUNCTION
2005 QX56
10. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Remove the intake air duct.
2. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 11.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
11. CHECK THROTTLE CONTROL MOTOR
Refer to EC-404, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 13.
12. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 13.
NG >> Repair or replace harness or connectors.
13. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
Component Inspection UBS00H7N
THROTTLE CONTROL MOTOR
1. Disconnect electric throttle control actuator harness connector.
2. Check resistance between terminals 5 and 6.
3. If NG, replace electric throttle control actuator and go to next
step.
4. Perform EC-90, "
Throttle Valve Closed Position Learning" .
5. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00H7O
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
BBIA0364E
Resistance: Approximately 1 - 15 Ω [at 25 °C (77°F)]
PBIB2066E
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
EC-405
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DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY PFP:16119
Component Description UBS00H7P
Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition
switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not
provided to the ECM.
CONSULT-II Reference Value in Data Monitor Mode UBS00H7Q
Specification data are reference values.
On Board Diagnosis Logic UBS00H7R
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MlL lights up.
DTC Confirmation Procedure UBS00H7S
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR DTC P1124
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V.
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. If DTC is detected, go to EC-408, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
MONITOR ITEM CONDITION SPECIFICATION
THRTL RELAY
● Ignition switch: ON ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1124
1124
Throttle control motor
relay circuit short
ECM detect the throttle control motor
relay is stuck ON.
● Harness or connectors
(Throttle control motor relay circuit is shorted)
● Throttle control motor relay
P1126
1126
Throttle control motor
relay circuit open
ECM detects a voltage of power source
for throttle control motor is excessively
low.
● Harness or connectors
(Throttle control motor relay circuit is open)
● Throttle control motor relay
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y
EC-406
Revision: October 2005
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
2005 QX56
PROCEDURE FOR DTC P1126
With CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR””mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-408, "
Diagnostic Procedure" .
With GST
Follow the procedure “With CONSULT-II” above.
SEF058Y
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
EC-407
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Wiring Diagram UBS00H7T
BBWA1695E
EC-408
Revision: October 2005
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H7U
1. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Check voltage between ECM terminal 104 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E122.
3. Check continuity between ECM terminal 104 and IPDM E/R terminal 47.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 7.
NG >> Replace 20A fuse.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
3L
Throttle control motor relay
power supply
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
104 O Throttle control motor relay
[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
Voltage: Battery voltage
PBIB1171E
Continuity should exist.
DTC P1124, P1126 THROTTLE CONTROL MOTOR RELAY
EC-409
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4. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-I
1. Check voltage between ECM terminal 3 and ground under the
following conditions with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 5.
5. CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect IPDM E/R harness connector E119.
4. Check continuity between ECM terminal 3 and IPDM E/R terminal 6.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R. Refer to PG-17, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MOD-
ULE ENGINE ROOM)" .
NG >> Repair or replace harness or connectors.
Ignition switch Voltage
OFF Approximately 0V
ON
Battery voltage
(11 - 14V)
MBIB0028E
Continuity should exist.
EC-410
Revision: October 2005
DTC P1128 THROTTLE CONTROL MOTOR
2005 QX56
DTC P1128 THROTTLE CONTROL MOTOR PFP:16119
Component Description UBS00H7V
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis Logic UBS00H7W
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure UBS00H7X
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-412, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1128
1128
Throttle control motor
circuit short
ECM detects short in both circuits between
ECM and throttle control motor.
● Harness or connectors
(Throttle control motor circuit is shorted.)
● Electric throttle control actuator
(Throttle control motor)
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y
DTC P1128 THROTTLE CONTROL MOTOR
EC-411
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H7Y
BBWA1696E
EC-412
Revision: October 2005
DTC P1128 THROTTLE CONTROL MOTOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00H7Z
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
4L/W
Throttle control motor
(Close)
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
0 - 14V
5L/B
Throttle control motor
(Open)
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
0 - 14V
PBIB1104E
PBIB1105E
BBIA0354E
DTC P1128 THROTTLE CONTROL MOTOR
EC-413
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2. CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Disconnect electric throttle control actuator harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK THROTTLE CONTROL MOTOR
Refer to EC-413, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> GO TO 5.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
Component Inspection UBS00H80
THROTTLE CONTROL MOTOR
1. Disconnect electric throttle control actuator harness connector.
2. Check resistance between terminals 5 and 6.
3. If NG, replace electric throttle control actuator and go to next
step.
4. Perform EC-90, "
Throttle Valve Closed Position Learning" .
5. Perform EC-91, "
Idle Air Volume Learning" .
Electric throttle control
actuator terminal
ECM terminal Continuity
5
5 Should not exist
4 Should exist
6
5 Should exist
4 Should not exist
BBIA0371E
Resistance: Approximately 1 - 15 Ω [at 25 °C (77°F)]
PBIB2066E
EC-414
Revision: October 2005
DTC P1128 THROTTLE CONTROL MOTOR
2005 QX56
Removal and Installation UBS00H81
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
DTC P1146, P1166 HO2S2
EC-415
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DTC P1146, P1166 HO2S2 PFP:226A0
Component Description UBS00H82
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor Mode UBS00H83
Specification data are reference values.
On Board Diagnosis Logic UBS00H84
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the minimum voltage of sensor is
sufficiently low during the various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
● Warm-up condition
● After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.
Revving engine from idle to 3,000 rpm
quickly.
0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
LEAN ←→ RICH
PBIB2376E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1146
1146
(Bank 1)
Heated oxygen sensor
2 minimum voltage
monitoring
The minimum voltage from the sensor is not
reached to the specified voltage.
● Harness or connectors
(The sensor circuit is open or shorted)
● Heated oxygen sensor 2
● Fuel pressure
● Fuel injector
P1166
1166
(Bank 2)
EC-416
Revision: October 2005
DTC P1146, P1166 HO2S2
2005 QX56
DTC Confirmation Procedure UBS00H85
NOTE:
If DTC confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70°C
(158°F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70°C (158°F).
7. Open engine hood.
8. Select “HO2S2 (B1) P1146” or “HO2S2 (B2) P1166” of “HO2S2” in “DTC WORK SUPPORT” mode with
CONSULT-II.
9. Start engine and following the instruction of CONSULT-II.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”.
If “NG” is displayed, refer to EC-421, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function Check UBS00H86
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
SEF174Y
PBIB2372E
DTC P1146, P1166 HO2S2
EC-417
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Revision: October 2005 2005 QX56
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be below 0.18V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, go to EC-421, "
Diagnostic Procedure" .
PBIB2054E
EC-418
Revision: October 2005
DTC P1146, P1166 HO2S2
2005 QX56
Wiring Diagram UBS00H87
BANK 1
BBWA1678E
DTC P1146, P1166 HO2S2
EC-419
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EC
Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
55 R
Heated oxygen sensor 2
(bank 1)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
EC-420
Revision: October 2005
DTC P1146, P1166 HO2S2
2005 QX56
BANK 2
BBWA1679E
DTC P1146, P1166 HO2S2
EC-421
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EC
Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H88
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
74 L
Heated oxygen sensor 2
(bank 2)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
BBIA0354E
EC-422
Revision: October 2005
DTC P1146, P1166 HO2S2
2005 QX56
2. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode
with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart
and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0172 or P0175. Refer to EC-245, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 3.
SEF968Y
BBIA0368E
DTC P1146, P1166 HO2S2
EC-423
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Revision: October 2005 2005 QX56
3. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Continuity should exist.
BBIA0435E
DTC
Terminals
Bank
ECM Sensor
P1146 55 1 1
P1166 74 1 2
Continuity should exist.
DTC
Terminals
Bank
ECM Sensor
P1146 55 1 1
P1166 74 1 2
Continuity should not exist.
EC-424
Revision: October 2005
DTC P1146, P1166 HO2S2
2005 QX56
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-424, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H89
HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.
7. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.58V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18V at least once when the “FUEL INJECTION” is −25%.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
SEF174Y
PBIB1672E
PBIB2636E
DTC P1146, P1166 HO2S2
EC-425
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Revision: October 2005 2005 QX56
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage is above 0.58V at step 6, step 7 is not neces-
sary.
7. Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and Installation UBS00H8A
HEATED OXYGEN SENSOR 2
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
PBIB2054E
EC-426
Revision: October 2005
DTC P1147, P1167 HO2S2
2005 QX56
DTC P1147, P1167 HO2S2 PFP:226A0
Component Description UBS00H8B
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor Mode UBS00H8C
Specification data are reference values.
On Board Diagnosis Logic UBS00H8D
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the maximum voltage of the sensor
is sufficiently high during the various driving condition such as fuel-
cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
● Warm-up condition
● After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.
Revving engine from idle to 3,000 rpm
quickly.
0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
LEAN ←→ RICH
PBIB1154E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1147
1147
(Bank 1)
Heated oxygen sensor
2 maximum voltage
monitoring
The maximum voltage from the sensor is not
reached to the specified voltage.
● Harness or connectors
(The sensor circuit is open or shorted)
● Heated oxygen sensor 2
● Fuel pressure
● Fuel injector
● Intake air leaks
P1167
1167
(Bank 2)
DTC P1147, P1167 HO2S2
EC-427
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Revision: October 2005 2005 QX56
DTC Confirmation Procedure UBS00H8E
NOTE:
If DTC confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70°C
(158°F).
If not, warm up engine and go to next step when “COOLAN
TEMP/S” indication reaches to 70°C (158°F).
7. Open engine hood.
8. Select “HO2S2 (B1) P1147” or “HO2S2 (B2) P1167” of “HO2S2” in “DTC WORK SUPPORT” mode with
CONSULT-II.
9. Start engine and following the instruction of CONSULT-II.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
10. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”.
If “NG” is displayed, refer to EC-432, "
Diagnostic Procedure" .
If “CAN NOT BE DIAGNOSED” is displayed, perform the following.
a. Turn ignition switch OFF and leave the vehicle in a cool place (soak the vehicle).
b. Return to step 1.
Overall Function Check UBS00H8F
Use this procedure to check the overall function of the heated oxygen sensor 2 circuit. During this check, a 1st
trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
SEF174Y
PBIB2373E
EC-428
Revision: October 2005
DTC P1147, P1167 HO2S2
2005 QX56
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage can be confirmed in step 6, step 7 is not nec-
essary.
7. Keep vehicle at idling for 10 minutes, then check the voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be above 0.58V at least once during this
procedure.
8. If NG, go to EC-432, "
Diagnostic Procedure" .
PBIB2054E
DTC P1147, P1167 HO2S2
EC-429
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EC
Revision: October 2005 2005 QX56
Wiring Diagram UBS00H8G
BANK 1
BBWA1678E
EC-430
Revision: October 2005
DTC P1147, P1167 HO2S2
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
55 R
Heated oxygen sensor 2
(bank 1)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
DTC P1147, P1167 HO2S2
EC-431
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Revision: October 2005 2005 QX56
BANK 2
BBWA1679E
EC-432
Revision: October 2005
DTC P1147, P1167 HO2S2
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H8H
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
74 L
Heated oxygen sensor 2
(bank 2)
[Engine is running]
● Warm-up condition
● Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
– After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load
0 - Approximately 1.0V
78 B/W
Sensor ground
(Heated oxygen sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
BBIA0354E
DTC P1147, P1167 HO2S2
EC-433
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EC
Revision: October 2005 2005 QX56
2. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode
with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector, and restart
and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Make sure DTC P0102 is displayed.
6. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
7. Make sure DTC P0000 is displayed.
8. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0171 or P0174. Refer to EC-236, "DTC P0171, P0174 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 3.
SEF968Y
BBIA0368E
EC-434
Revision: October 2005
DTC P1147, P1167 HO2S2
2005 QX56
3. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminal 78 and HO2S2 terminal 4.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Continuity should exist.
BBIA0435E
DTC
Te r mi na ls
Bank
ECM Sensor
P1147 55 1 1
P1167 74 1 2
Continuity should exist.
DTC
Te r mi na ls
Bank
ECM Sensor
P1147 55 1 1
P1167 74 1 2
Continuity should not exist.
DTC P1147, P1167 HO2S2
EC-435
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Revision: October 2005 2005 QX56
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-435, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00H8I
HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.
7. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.58V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18V at least once when the “FUEL INJECTION” is −25%.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
SEF174Y
PBIB1672E
PBIB2636E
EC-436
Revision: October 2005
DTC P1147, P1167 HO2S2
2005 QX56
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 55 [HO2S2 (B1) signal] or 74 [HO2S2 (B2) signal] and
ground.
6. Check the voltage when revving up to 4,000 rpm under no load
at least 10 times.
(Depress and release accelerator pedal as soon as possible.)
The voltage should be above 0.58V at least once during this
procedure.
If the voltage is above 0.58V at step 6, step 7 is not neces-
sary.
7. Keep vehicle at idling for 10 minutes, then check voltage. Or
check the voltage when coasting from 80 km/h (50 MPH) in D
position.
The voltage should be below 0.18V at least once during this
procedure.
8. If NG, replace heated oxygen sensor 2.
CAUTION:
● Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and Installation UBS00H8J
HEATED OXYGEN SENSOR 2
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
PBIB2054E
DTC P1148, P1168 CLOSED LOOP CONTROL
EC-437
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Revision: October 2005 2005 QX56
DTC P1148, P1168 CLOSED LOOP CONTROL PFP:22690
On Board Diagnosis Logic UBS00H8K
These self-diagnoses have the one trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
1148
(Bank 1)
Closed loop control
function
The closed loop control function for bank 1
does not operate even when vehicle is driving
in the specified condition.
● Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]
● Air fuel ratio (A/F) sensor 1
● Air fuel ratio (A/F) sensor 1 heater
P1168
1168
(Bank 2)
The closed loop control function for bank 2
does not operate even when vehicle is driving
in the specified condition.
EC-438
Revision: October 2005
DTC P1211 TCS CONTROL UNIT
2005 QX56
DTC P1211 TCS CONTROL UNIT PFP:47850
Description UBS00H8L
The malfunction information related to TCS is transferred through the CAN communication line from “ABS
actuator and electric unit (control unit)” to ECM.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagnosis Logic UBS00H8M
Freeze frame data is not stored in the ECM for this self-diagnosis.
The MIL will not light up for this self-diagnosis.
DTC Confirmation Procedure UBS00H8N
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 60 seconds.
4. If 1st trip DTC is detected, go to EC-438, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00H8O
Go to BRC-11, "TROUBLE DIAGNOSIS" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1211
1211
TCS control unit
ECM receives a malfunction information from
“ABS actuator electric unit (control unit)”
● ABS actuator and electric unit (control
unit)
● TCS related parts
SEF058Y
DTC P1212 TCS COMMUNICATION LINE
EC-439
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Revision: October 2005 2005 QX56
DTC P1212 TCS COMMUNICATION LINE PFP:47850
Description UBS00H8P
NOTE:
If DTC P1212 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
This CAN communication line is used to control the smooth engine operation during the TCS operation. Pulse
signals are exchanged between ECM and “ABS actuator and electric unit (control unit)”.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagnosis Logic UBS00H8Q
Freeze frame data is not stored in the ECM for this self-diagnosis.
The MIL will not light up for this self-diagnosis.
DTC Confirmation Procedure UBS00H8R
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 10 seconds.
4. If 1st trip DTC is detected, go to EC-439, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00H8S
Go to BRC-11, "TROUBLE DIAGNOSIS" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1212
1212
TCS communication
line
ECM can not receive the information
from “ABS actuator and electric unit (con-
trol unit)” continuously.
● Harness or connectors
(The CAN communication line is open or
shorted.)
● ABS actuator and electric unit (control unit)
● Dead (Weak) battery
SEF058Y
EC-440
Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
DTC P1217 ENGINE OVER TEMPERATURE PFP:00000
Description UBS00H8T
SYSTEM DESCRIPTION
NOTE:
If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC U1000,
U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
Cooling Fan Control
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM through CAN communication line.
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 2-step control [HI/OFF].
Cooling Fan Operation
CONSULT-II Reference Value in Data Monitor Mode UBS00H8U
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*
1
Cooling fan
control
IPDM E/R
(Cooling fan relay)
Battery
Battery voltage*
1
Wheel sensor*
2
Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch
Air conditioner ON signal*
2
Refrigerant pressure sensor Refrigerant pressure
PBIB2060E
MONITOR ITEM CONDITION SPECIFICATION
COOLING FAN
● Engine: After warming up, idle
the engine
Engine coolant temperature: 99°C
(210°F) or less
OFF
Engine coolant temperature: 100°C
(212°F) or more
HI
DTC P1217 ENGINE OVER TEMPERATURE
EC-441
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On Board Diagnosis Logic UBS00H8V
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
This self-diagnosis has the one trip detection logic.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant. Refer to CO-10, "
Changing Engine
Coolant" . Also, replace the engine oil. Refer to LU-8, "Changing Engine Oil" .
1. Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to
use coolant with the proper mixture ratio. Refer to MA-12, "
ANTI-FREEZE COOLANT MIXTURE
RATIO" .
2. After refilling coolant, run engine to ensure that no water-flow noise is emitted.
Overall Function Check UBS00H8W
Use this procedure to check the overall function of the cooling fan. During this check, a DTC might not be con-
firmed.
WARNING:
Never remove the radiator cap when the engine is hot. Serious burns could be caused by high pres-
sure fluid escaping from the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by turning it a quarter turn to allow built-up
pressure to escape. Then turn the cap all the way off.
WITH CONSULT-II
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to EC-445,
"Diagnostic Procedure" .
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-445,
"Diagnostic Procedure" .
3. Turn ignition switch ON.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1217
1217
Engine over tempera-
ture (Overheat)
● Cooling fan does not operate properly (Over-
heat).
● Cooling fan system does not operate prop-
erly (Overheat).
● Engine coolant was not added to the system
using the proper filling method.
● Engine coolant is not within the specified
range.
● Harness or connectors
(The cooling fan circuit is open or
shorted.)
● Cooling fan
● IPDM E/R (Cooling fan relay)
● Radiator hose
● Radiator
● Radiator cap
● Water pump
● Thermostat
For more information, refer to EC-448,
"Main 12 Causes of Overheating" .
SEF621W
EC-442
Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
4. Perform “COOLING FAN” in “ACTIVE TEST” mode with CON-
SULT-II.
5. If the results are NG, go to EC-445, "
Diagnostic Procedure" .
WITH GST
1. Check the coolant level in the reservoir tank and radiator.
Allow engine to cool before checking coolant level.
If the coolant level in the reservoir tank and/or radiator is below
the proper range, skip the following steps and go to EC-445,
"Diagnostic Procedure" .
2. Confirm whether customer filled the coolant or not. If customer
filled the coolant, skip the following steps and go to EC-445,
"Diagnostic Procedure" .
3. Disconnect engine coolant temperature sensor harness connec-
tor.
4. Connect 150Ω resistor to engine coolant temperature sensor
harness connector.
5. Start engine and make sure that cooling fan operates.
CAUTION:
Be careful not to overheat engine.
6. If NG, go to EC-445, "
Diagnostic Procedure" .
SEF646X
SEF621W
SEF882V
DTC P1217 ENGINE OVER TEMPERATURE
EC-443
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Wiring Diagram UBS00H8X
BBWA1697E
EC-444
Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
BBWA1698E
DTC P1217 ENGINE OVER TEMPERATURE
EC-445
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Diagnostic Procedure UBS00H8Y
1. INSPECTION START
Do you have CONSULT-II?
Yes or No
Yes >> GO TO 2.
No >> GO TO 3.
2. CHECK COOLING FAN MOTOR OPERATION
With CONSULT-II
1. Start engine and let it idle.
2. Select “COOLING FAN” in “ACTIVE TEST” mode with CON-
SULT-II.
3. Make sure that cooling fan operates.
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to EC-447, "
PRO-
CEDURE A" .)
3. CHECK COOLING FAN MOTOR OPERATION
Without CONSULT-II
1. Disconnect engine coolant temperature sensor harness connector.
2. Connect 150Ω resistor to engine coolant temperature sensor harness connector.
3. Start engine and let it idle.
4. Make sure that cooling fan operates.
OK or NG
OK >> GO TO 4.
NG >> Check cooling fan control circuit. (Go to EC-447, "
PRO-
CEDURE A" .)
SEF646X
SEF882V
EC-446
Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
4. CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the
pressure drops.
CAUTION:
Higher than the specified pressure may cause radiator damage.
Pressure should not drop.
OK or NG
OK >> GO TO 5.
NG >> Check the following for leak. Refer to CO-10, "
CHECK-
ING COOLING SYSTEM FOR LEAKS" .
● Hose
● Radiator
● Water pump
5. CHECK RADIATOR CAP
Apply pressure to cap with a tester.
OK or NG
OK >> GO TO 6.
NG >> Replace radiator cap.
6. CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve lift.
3. Check if valve is closed at 5°C (9°F) below valve opening tem-
perature.
For details, refer to CO-19, "
THERMOSTAT AND WATER PIP-
ING" .
OK or NG
OK >> GO TO 7.
NG >> Replace thermostat
7. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-199, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace engine coolant temperature sensor.
Testing pressure: 157 kPa (1.6 kg/cm
2
, 23 psi)
PBIC1528E
Radiator cap relief
pressure:
59 - 98 kPa (0.6 - 1.0 kg/cm
2
, 9 - 14 psi)
SLC755A
Valve opening temperature: 82°C (180°F) [standard]
Valve lift: More than 10.0 mm/95°C
(0.394 in/203°F)
SLC343
DTC P1217 ENGINE OVER TEMPERATURE
EC-447
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8. CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to EC-448, "
Main 12 Causes of Overheating" .
>> INSPECTION END
PROCEDURE A
1. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector E120.
3. Check voltage between IPDM E/R terminal 22 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.
● 40A fusible link
● Harness for open or short between IPDM E/R and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK COOLING FAN MOTOR CIRCUIT FOR OPEN OR SHORT
1. Disconnect cooling fan motor harness connector.
2. Check harness continuity between cooling fan motor terminal 1
and IPDM E/R terminal 24, cooling fan motor terminal 2 and
ground.
Refer to wiring diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
4. CHECK COOLING FAN MOTOR
Refer to EC-449, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace cooling fan motor.
Voltage: Battery voltage
PBIB2067E
Continuity should exist.
BBIA0446E
EC-448
Revision: October 2005
DTC P1217 ENGINE OVER TEMPERATURE
2005 QX56
5. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R. Refer to PG-17, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MOD-
ULE ENGINE ROOM)" .
NG >> Repair or replace harness connectors.
Main 12 Causes of Overheating UBS00H8Z
*1: Turn the ignition switch ON.
*2: Engine running at 3,000 rpm for 10 minutes.
*3: Drive at 90 km/h (55 MPH) for 30 minutes and then let idle for 10 minutes.
*4: After 60 minutes of cool down time.
For more information, refer to CO-6, "
OVERHEATING CAUSE ANALYSIS" .
Engine Step Inspection item Equipment Standard Reference page
OFF 1
● Blocked radiator
● Blocked condenser
● Blocked radiator grille
● Blocked bumper
● Visual No blocking —
2
● Coolant mixture ● Coolant tester 50 - 50% coolant mixture MA-11, "RECOM-
MENDED FLUIDS AND
LUBRICANTS"
3 ● Coolant level ● Visual Coolant up to MAX level
in reservoir tank and radi-
ator filler neck
CO-10, "
Changing
Engine Coolant"
4 ● Radiator cap ● Pressure tester 59 - 98 kPa
(0.6 - 1.0 kg/cm
2
, 9 - 14
psi) (Limit)
CO-10, "
CHECKING
RESERVOIR CAP"
ON*
2
5 ● Coolant leaks ● Visual No leaks CO-10, "CHECKING
COOLING SYSTEM FOR
LEAKS"
ON*
2
6 ● Thermostat ● Touch the upper and
lower radiator hoses
Both hoses should be hot CO-19, "THERMOSTAT
AND WATER PIPING"
ON*
1
7 ● Cooling fan ● CONSULT-II Operating See trouble diagnosis for
DTC P1217 (EC-440,
"DTC P1217 ENGINE
OVER TEMPERATURE"
).
OFF 8
● Combustion gas leak ● Color checker chemical
tester 4 Gas analyzer
Negative —
ON*
3
9 ● Coolant temperature
gauge
● Visual Gauge less than 3/4
when driving
—
● Coolant overflow to
reservoir tank
● Visual No overflow during driving
and idling
CO-10, "Changing
Engine Coolant"
OFF*
4
10 ● Coolant return from
reservoir tank to radia-
tor
● Visual Should be initial level in
reservoir tank
CO-10, "Changing
Engine Coolant"
OFF 11 ● Cylinder head ● Straight gauge feeler
gauge
0.1 mm (0.004 in) Maxi-
mum distortion (warping)
EM-63, "Inspection After
Disassembly"
12 ● Cylinder block and pis-
tons
● Visual No scuffing on cylinder
walls or piston
EM-89, "Inspection After
Disassembly"
DTC P1217 ENGINE OVER TEMPERATURE
EC-449
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Component Inspection UBS00H90
COOLING FAN MOTOR
1. Disconnect cooling fan motor harness connector.
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Cooling fan motor should operate.
If NG, replace cooling fan motor.
SEF888V
EC-450
Revision: October 2005
DTC P1225 TP SENSOR
2005 QX56
DTC P1225 TP SENSOR PFP:16119
Component Description UBS00H91
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagnosis Logic UBS00H92
The MIL will not light up for this diagnosis.
DTC Confirmation Procedure UBS00H93
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. If 1st trip DTC is detected, go to EC-451, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1225
1225
Closed throttle position learning
performance problem
Closed throttle position learning value is
excessively low.
● Electric throttle control actuator
(TP sensor 1 and 2)
SEF058Y
DTC P1225 TP SENSOR
EC-451
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Diagnostic Procedure UBS00H94
1. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
2. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
Removal and Installation UBS00H95
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
BBIA0364E
EC-452
Revision: October 2005
DTC P1226 TP SENSOR
2005 QX56
DTC P1226 TP SENSOR PFP:16119
Component Description UBS00H96
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagnosis Logic UBS00H97
The MIL will not light up for this diagnosis.
DTC Confirmation Procedure UBS00H98
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Repeat steps 3 and 4 for 32 times.
6. If 1st trip DTC is detected, go to EC-453, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1226
1226
Closed throttle position learning
performance problem
Closed throttle position learning is not performed
successfully, repeatedly.
● Electric throttle control actuator
(TP sensor 1 and 2)
SEF058Y
DTC P1226 TP SENSOR
EC-453
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Diagnostic Procedure UBS00H99
1. CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
2. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
Removal and Installation UBS00H9A
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
BBIA0364E
EC-454
Revision: October 2005
DTC P1229 SENSOR POWER SUPPLY
2005 QX56
DTC P1229 SENSOR POWER SUPPLY PFP:16119
On Board Diagnosis Logic UBS00H9B
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation Procedure UBS00H9C
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-456, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1229
1229
Sensor power supply circuit
short
ECM detects a voltage of power source
for sensor is excessively low or high.
● Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
(EVAP control system pressure sensor circuit
is shorted.)
● Accelerator pedal position sensor
● Power steering pressure sensor
● Refrigerant pressure sensor
● EVAP control system pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y
DTC P1229 SENSOR POWER SUPPLY
EC-455
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Wiring Diagram UBS00H9D
BBWA1699E
EC-456
Revision: October 2005
DTC P1229 SENSOR POWER SUPPLY
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H9E
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
48 SB
Sensor power supply
(EVAP control system
pressure sensor)
[Ignition switch: ON] Approximately 5V
49 R/Y
Sensor power supply
(Refrigerant pressure
sensor)
[Ignition switch: ON] Approximately 5V
68 W/L
Sensor power supply
(Power steering pressure
sensor)
[Ignition switch: ON] Approximately 5V
90 L
Sensor power supply
(APP sensor 1)
[Ignition switch: ON] Approximately 5V
BBIA0354E
DTC P1229 SENSOR POWER SUPPLY
EC-457
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2. CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 7 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3. CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4. CHECK COMPONENTS
Check the following.
● EVAP control system pressure sensor (Refer to EC-340, "Component Inspection" .)
● Power steering pressure sensor (Refer to EC-382, "Component Inspection" .)
● Refrigerant pressure sensor (Refer to EC-643, "REFRIGERANT PRESSURE SENSOR" .)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning components.
5. CHECK ACCELERATOR PEEDAL POSITION SENSOR
Refer to EC-618, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
BBIA0361E
Voltage: Approximately 5V
PBIB2070E
ECM terminal Sensor terminal Reference Wiring Diagram
48 EVAP control system pressure sensor terminal 3 EC-337
49 Refrigerant pressure sensor terminal 1 EC-644
68 Power steering pressure sensor terminal 1 EC-379
90 APP sensor terminal 7 EC-455
EC-458
Revision: October 2005
DTC P1229 SENSOR POWER SUPPLY
2005 QX56
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal position assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
DTC P1271, P1281 A/F SENSOR 1
EC-459
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DTC P1271, P1281 A/F SENSOR 1 PFP:22693
Component Description UBS00H9F
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00H9G
Specification data are reference values.
On Board Diagnosis Logic UBS00H9H
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately low.
DTC Confirmation Procedure UBS00H9I
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1271
1271
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit no activity detected
● The A/F signal computed by ECM from the
A/F sensor 1 signal is constantly approx. 0V.
● Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
● Air fuel ratio (A/F) sensor 1
P1281
1281
(Bank 2)
EC-460
Revision: October 2005
DTC P1271, P1281 A/F SENSOR 1
2005 QX56
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 0V, go to EC-464, "
Diag-
nostic Procedure" .
If the indication is not constantly approx. 0V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then
restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH)
within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive sec-
onds.
NOTE:
● Keep the accelerator pedal as steady as possible during the cruising.
● If this procedure is not completed within 1 minute after restarting engine at step 4, return to step
4.
7. If 1st trip DTC is displayed, go to EC-464, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
SEF581Z
DTC P1271, P1281 A/F SENSOR 1
EC-461
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H9J
BANK 1
BBWA1700E
EC-462
Revision: October 2005
DTC P1271, P1281 A/F SENSOR 1
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
DTC P1271, P1281 A/F SENSOR 1
EC-463
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Revision: October 2005 2005 QX56
BANK 2
BBWA1701E
EC-464
Revision: October 2005
DTC P1271, P1281 A/F SENSOR 1
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H9K
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
DTC P1271, P1281 A/F SENSOR 1
EC-465
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Revision: October 2005 2005 QX56
2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
EC-466
Revision: October 2005
DTC P1271, P1281 A/F SENSOR 1
2005 QX56
4. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace.
6. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
DTC P1271, P1281 A/F SENSOR 1
EC-467
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Revision: October 2005 2005 QX56
Removal and Installation UBS00H9L
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
EC-468
Revision: October 2005
DTC P1272, P1282 A/F SENSOR 1
2005 QX56
DTC P1272, P1282 A/F SENSOR 1 PFP:22693
Component Description UBS00H9M
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00H9N
Specification data are reference values.
On Board Diagnosis Logic UBS00H9O
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately high.
DTC Confirmation Procedure UBS00H9P
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1272
1272
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit no activity detected
● The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 5V.
● Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
● Air fuel ratio (A/F) sensor 1
P1282
1282
(Bank 2)
DTC P1272, P1282 A/F SENSOR 1
EC-469
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Revision: October 2005 2005 QX56
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 5V, go to EC-473, "
Diag-
nostic Procedure" .
If the indication is not constantly approx. 5V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then
restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH)
within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive sec-
onds.
NOTE:
● Keep the accelerator pedal as steady as possible during the cruising.
● If this procedure is not completed within 1 minute after restarting engine at step 4, return to step
4.
7. If 1st trip DTC is displayed, go to EC-473, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
SEF581Z
EC-470
Revision: October 2005
DTC P1272, P1282 A/F SENSOR 1
2005 QX56
Wiring Diagram UBS00H9Q
BANK 1
BBWA1700E
DTC P1272, P1282 A/F SENSOR 1
EC-471
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
EC-472
Revision: October 2005
DTC P1272, P1282 A/F SENSOR 1
2005 QX56
BANK 2
BBWA1701E
DTC P1272, P1282 A/F SENSOR 1
EC-473
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H9R
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
EC-474
Revision: October 2005
DTC P1272, P1282 A/F SENSOR 1
2005 QX56
2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
DTC P1272, P1282 A/F SENSOR 1
EC-475
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Revision: October 2005 2005 QX56
4. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace.
6. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
EC-476
Revision: October 2005
DTC P1272, P1282 A/F SENSOR 1
2005 QX56
Removal and Installation UBS00H9S
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
DTC P1273, P1283 A/F SENSOR 1
EC-477
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Revision: October 2005 2005 QX56
DTC P1273, P1283 A/F SENSOR 1 PFP:22693
Component Description UBS00H9T
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00H9U
Specification data are reference values.
On Board Diagnosis Logic UBS00H9V
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation Procedure UBS00H9W
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1273
1273
(Bank 1)
Air fuel ratio (A/F) sensor 1
lean shift monitoring
● The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side
for a specified period.
● Air fuel ratio (A/F) sensor 1
● Air fuel ratio (A/F) sensor 1 heater
● Fuel pressure
● Fuel injector
● Intake air leaks
P1283
1283
(Bank 2)
EC-478
Revision: October 2005
DTC P1273, P1283 A/F SENSOR 1
2005 QX56
4. Clear the self-learning coefficient by touching “CLEAR”.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Start engine and keep the engine speed between 3,500 and
4,000 rpm for 1 minute under no load.
7. Let engine idle for 1 minute.
8. Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.
9. If 1st trip DTC is detected, go to EC-482, "
Diagnostic Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Start engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST and make sure that DTC P0102 is
detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine and keep the engine speed between 3,500 and
4,000 rpm for 1 minute under no load.
9. Let engine idle for 1 minute.
10. Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.
11. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-482, "
Diagnostic Procedure" .
SEF968Y
BBIA0368E
DTC P1273, P1283 A/F SENSOR 1
EC-479
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00H9X
BANK 1
BBWA1700E
EC-480
Revision: October 2005
DTC P1273, P1283 A/F SENSOR 1
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
DTC P1273, P1283 A/F SENSOR 1
EC-481
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Revision: October 2005 2005 QX56
BANK 2
BBWA1701E
EC-482
Revision: October 2005
DTC P1273, P1283 A/F SENSOR 1
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00H9Y
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
BBIA0375E
DTC P1273, P1283 A/F SENSOR 1
EC-483
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Revision: October 2005 2005 QX56
3. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0171 or P0174. Refer to EC-236, "DTC P0171, P0174 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 4.
SEF968Y
BBIA0368E
EC-484
Revision: October 2005
DTC P1273, P1283 A/F SENSOR 1
2005 QX56
4. CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Turn ignition switch ON.
4. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
DTC P1273, P1283 A/F SENSOR 1
EC-485
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Revision: October 2005 2005 QX56
6. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK A/F SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 9.
8. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace.
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
EC-486
Revision: October 2005
DTC P1273, P1283 A/F SENSOR 1
2005 QX56
9. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
Removal and Installation UBS00H9Z
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
DTC P1274, P1284 A/F SENSOR 1
EC-487
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DTC P1274, P1284 A/F SENSOR 1 PFP:22693
Component Description UBS00HA0
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00HA1
Specification data are reference values.
On Board Diagnosis Logic UBS00HA2
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation Procedure UBS00HA3
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1274
1274
(Bank 1)
Air fuel ratio (A/F) sensor 1
rich shift monitoring
● The A/F signal computed by ECM from the
A/F sensor 1 signal is shifted to the rich side
for a specified period.
● Air fuel ratio (A/F) sensor 1
● Air fuel ratio (A/F) sensor 1 heater
● Fuel pressure
● Fuel injector
P1284
1244
(Bank 2)
EC-488
Revision: October 2005
DTC P1274, P1284 A/F SENSOR 1
2005 QX56
4. Clear the self-learning coefficient by touching “CLEAR”.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Start engine and keep the engine speed between 3,500 and
4,000 rpm for 1 minute under no load.
7. Let engine idle for 1 minute.
8. Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.
9. If 1st trip DTC is detected, go to EC-492, "
Diagnostic Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Start engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST and make sure that DTC P0102 is
detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine and keep the engine speed between 3,500 and
4,000 rpm for 1 minute under no load.
9. Let engine idle for 1 minute.
10. Keep engine speed between 2,500 and 3,000 rpm for 20 min-
utes.
11. Select Service $07 with GST.
If 1st trip DTC is detected, go to EC-492, "
Diagnostic Procedure" .
SEF968Y
PBIB1077E
DTC P1274, P1284 A/F SENSOR 1
EC-489
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Wiring Diagram UBS00HA4
BANK 1
BBWA1700E
EC-490
Revision: October 2005
DTC P1274, P1284 A/F SENSOR 1
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
DTC P1274, P1284 A/F SENSOR 1
EC-491
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Revision: October 2005 2005 QX56
BANK 2
BBWA1701E
EC-492
Revision: October 2005
DTC P1274, P1284 A/F SENSOR 1
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HA5
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
BBIA0375E
DTC P1274, P1284 A/F SENSOR 1
EC-493
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3. CLEAR THE SELF-LEARNING DATA.
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0172 or P0175. Refer to EC-245, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 4.
SEF968Y
BBIA0368E
EC-494
Revision: October 2005
DTC P1274, P1284 A/F SENSOR 1
2005 QX56
4. CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water.
Water should not exit.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness connector.
5. CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
BBIA0376E
Voltage: Battery voltage
PBIB1683E
DTC P1274, P1284 A/F SENSOR 1
EC-495
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7. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK A/F SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> GO TO 10.
9. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 10.
NG >> Repair or replace.
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
EC-496
Revision: October 2005
DTC P1274, P1284 A/F SENSOR 1
2005 QX56
10. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
Removal and Installation UBS00HA6
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
DTC P1276, P1286 A/F SENSOR 1
EC-497
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DTC P1276, P1286 A/F SENSOR 1 PFP:22693
Component Description UBS00HA7
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00HA8
Specification data are reference values.
On Board Diagnosis Logic UBS00HA9
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
DTC Confirmation Procedure UBS00HAA
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1276
1276
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit high voltage
● The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 1.5V.
● Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
● Air fuel ratio (A/F) sensor 1
P1286
1286
(Bank 2)
EC-498
Revision: October 2005
DTC P1276, P1286 A/F SENSOR 1
2005 QX56
If the indication is constantly approx. 1.5V and does not fluctuates, go to EC-503, "Diagnostic Procedure" .
If the indication fluctuates around 1.5V, go to next step.
4. Select “A/F SEN1 (B1) P1276” or “A/F SEN1 (B2) P1286” of “A/F SEN1” in “DTC WORK SUPPORT”
mode with CONSULT-II.
5. Touch “START”.
6. When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen.
If “TESTING” is not displayed after 20 seconds, retry from
step 2.
7. Release accelerator pedal fully.
NOTE:
Never apply brake during releasing the accelerator pedal.
8. Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, retry from
step 6.
9. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to EC-503, "
Diagnostic Procedure" .
Overall Function Check UBS00HAB
Use this procedure to check the overall function of the A/F sensor 1 circuit. During this check, a 1st trip DTC
might not be confirmed.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.
3. Set D position, then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30
MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
4. Repeat steps 2 to 3 for five times.
5. Stop the vehicle and turn ignition switch OFF.
6. Wait at least 10 seconds and restart engine.
7. Repeat steps 2 to 3 for five times.
ENG SPEED 850 - 3,200 rpm
Vehicle speed More than 64 km/h (40 MPH)
B/FUEL SCHDL 1.0 - 8.0 msec
Selector lever D position with “OD” ON
SEF576Z
SEF577Z
SEF578Z
EC-500
Revision: October 2005
DTC P1276, P1286 A/F SENSOR 1
2005 QX56
Wiring Diagram UBS00HAC
BANK 1
BBWA1700E
DTC P1276, P1286 A/F SENSOR 1
EC-501
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
EC-502
Revision: October 2005
DTC P1276, P1286 A/F SENSOR 1
2005 QX56
BANK 2
BBWA1701E
DTC P1276, P1286 A/F SENSOR 1
EC-503
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HAD
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
EC-504
Revision: October 2005
DTC P1276, P1286 A/F SENSOR 1
2005 QX56
2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
DTC P1276, P1286 A/F SENSOR 1
EC-505
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4. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace.
6. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
EC-506
Revision: October 2005
DTC P1276, P1286 A/F SENSOR 1
2005 QX56
Removal and Installation UBS00HAE
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
DTC P1278, P1288 A/F SENSOR 1
EC-507
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DTC P1278, P1288 A/F SENSOR 1 PFP:22693
Component Description UBS00HAF
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00HAG
Specification data are reference values.
On Board Diagnosis Logic UBS00HAH
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1278
1278
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response
● The response (from RICH to LEAN) of the A/F
signal computed by ECM from A/F sensor 1
signal takes more than the specified time.
● Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
● Air fuel ratio (A/F) sensor 1
● Air fuel ratio (A/F) sensor 1 heater
● Fuel pressure
● Fuel injector
● Intake air leaks
● Exhaust gas leaks
● PCV
● Mass air flow sensor
P1288
1288
(Bank 2)
EC-508
Revision: October 2005
DTC P1278, P1288 A/F SENSOR 1
2005 QX56
DTC Confirmation Procedure UBS00HAI
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279” or “A/F SEN1(B1) P1288/P1289” of “A/F SEN1” in “DTC WORK
SUPPORT” mode with CONSULT-II.
6. Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED” does not appear on CONSULT-II screen, go to
the following step.
7. After perform the following procedure, “TESTING” will be dis-
played on the CONSULT-II screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it
for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about
10 seconds.
If “TESTING” is not displayed after 10 seconds, refer to EC-
146, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
8. Wait for about 20 seconds at idle at under the condition that
“TESTING” is displayed on the CONSULT-II screen.
9. Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, refer to
EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
10. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to EC-513, "
Diagnostic Procedure" .
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
PBIB0756E
PBIB1925E
PBIB0758E
DTC P1278, P1288 A/F SENSOR 1
EC-509
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● Intake air leaks
● Exhaust gas leaks
● Incorrect fuel pressure
● Lack of fuel
● Fuel injector
● Incorrect PCV hose connection
● PCV valve
● Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST.
If the 1st trip DTC is displayed, go to EC-513, "
Diagnostic Procedure" .
EC-510
Revision: October 2005
DTC P1278, P1288 A/F SENSOR 1
2005 QX56
Wiring Diagram UBS00HAJ
BANK 1
BBWA1700E
DTC P1278, P1288 A/F SENSOR 1
EC-511
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
EC-512
Revision: October 2005
DTC P1278, P1288 A/F SENSOR 1
2005 QX56
BANK 2
BBWA1701E
DTC P1278, P1288 A/F SENSOR 1
EC-513
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HAK
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
BBIA0375E
EC-514
Revision: October 2005
DTC P1278, P1288 A/F SENSOR 1
2005 QX56
3. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace.
PBIB1216E
DTC P1278, P1288 A/F SENSOR 1
EC-515
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5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”
or “START”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-236, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-245, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 6.
SEF968Y
BBIA0368E
EC-516
Revision: October 2005
DTC P1278, P1288 A/F SENSOR 1
2005 QX56
6. CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Turn ignition switch ON.
4. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
DTC P1278, P1288 A/F SENSOR 1
EC-517
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8. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 13.
10. CHECK MASS AIR FLOW SENSOR
Refer to EC-181, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
EC-518
Revision: October 2005
DTC P1278, P1288 A/F SENSOR 1
2005 QX56
11. CHECK PCV VALVE
Refer to EC-45, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> Repair or replace PCV valve.
12. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 13.
NG >> Repair or replace.
13. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
Removal and Installation UBS00HAL
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
DTC P1279, P1289 A/F SENSOR 1
EC-519
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DTC P1279, P1289 A/F SENSOR 1 PFP:22693
Component Description UBS00HAM
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor Mode UBS00HAN
Specification data are reference values.
On Board Diagnosis Logic UBS00HAO
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
● Engine: After warming up
Maintaining engine speed at
2,000 rpm
Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1279
1279
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response
● The response (from LEAN to RICH) of the A/F
signal computed by ECM from A/F sensor 1
signal takes more than the specified time.
● Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
● Air fuel ratio (A/F) sensor 1
● Air fuel ratio (A/F) sensor 1 heater
● Fuel pressure
● Fuel injector
● Intake air leaks
● Exhaust gas leaks
● PCV
● Mass air flow sensor
P1289
1289
(Bank 2)
EC-520
Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
DTC Confirmation Procedure UBS00HAP
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279” or “A/F SEN1(B1) P1288/P1289” of “A/F SEN1” in “DTC WORK
SUPPORT” mode with CONSULT-II.
6. Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED” does not appear on CONSULT-II screen, go to
the following step.
7. After perform the following procedure, “TESTING” will be dis-
played on the CONSULT-II screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it
for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about
10 seconds.
If “TESTING” is not displayed after 10 seconds, refer to EC-
146, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
8. Wait for about 20 seconds at idle at under the condition that
“TESTING” is displayed on the CONSULT-II screen.
9. Make sure that “TESTING” changes to “COMPLETED”.
If “TESTING” changed to “OUT OF CONDITION”, refer to
EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
10. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT”.
If “NG” is displayed, go to EC-525, "
Diagnostic Procedure" .
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Calculate the total value of “Short term fuel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
PBIB0756E
PBIB1925E
PBIB0758E
DTC P1279, P1289 A/F SENSOR 1
EC-521
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● Intake air leaks
● Exhaust gas leaks
● Incorrect fuel pressure
● Lack of fuel
● Fuel injector
● Incorrect PCV hose connection
● PCV valve
● Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST.
If the 1st trip DTC is displayed, go to EC-525, "
Diagnostic Procedure" .
EC-522
Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
Wiring Diagram UBS00HAQ
BANK 1
BBWA1700E
DTC P1279, P1289 A/F SENSOR 1
EC-523
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
16 BR/R
A/F sensor 1 (bank 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
EC-524
Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
BANK 2
BBWA1701E
DTC P1279, P1289 A/F SENSOR 1
EC-525
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HAR
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
57 L/P
A/F sensor 1 (bank 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
BBIA0354E
Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
BBIA0375E
EC-526
Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
3. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (Manifold).
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace.
PBIB1216E
DTC P1279, P1289 A/F SENSOR 1
EC-527
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5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR”
or “START”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-62, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Yes or No
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-236, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-245, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 6.
SEF968Y
BBIA0368E
EC-528
Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
6. CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Turn ignition switch ON.
4. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● IPDM E/R harness connector E119
● 10A fuse
● Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
BBIA0376E
PBIB1683E
DTC P1279, P1289 A/F SENSOR 1
EC-529
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8. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
5. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 13.
10. CHECK MASS AIR FLOW SENSOR
Refer to EC-181, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace mass air flow sensor.
A/F sensor 1 terminal ECM terminal
Bank1
116
275
535
656
Bank 2
176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
EC-530
Revision: October 2005
DTC P1279, P1289 A/F SENSOR 1
2005 QX56
11. CHECK PCV VALVE
Refer to EC-45, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> Repair or replace PCV valve.
12. CHECK INTERMITTENT INCIDENT
Perform EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 13.
NG >> Repair or replace.
13. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
● Discard any air fuel ratio (A/F) sensor which has been dropped from a height of more than 0.5 m
(19.7 in) onto a hard surface such as a concrete floor; use a new one.
● Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads (using Oxygen Sen-
sor Thread Cleaner tool J-43897-18 or J-43897-12) and approved anti-seize lubricant.
>> INSPECTION END
Removal and Installation UBS00HAS
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-531
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DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
PFP:14920
Description UBS00HAT
SYSTEM DESCRIPTION
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM through CAN communication line.
This system controls flow rate of fuel vapor from the EVAP canister. The opening of the vapor by-pass pas-
sage in the EVAP canister purge volume control solenoid valve changes to control the flow rate. The EVAP
canister purge volume control solenoid valve repeats ON/OFF operation according to the signal sent from the
ECM. The opening of the valve varies for optimum engine control. The optimum value stored in the ECM is
determined by considering various engine conditions. When the engine is operating, the flow rate of fuel vapor
from the EVAP canister is regulated as the air flow changes.
COMPONENT DESCRIPTION
The EVAP canister purge volume control solenoid valve uses a ON/
OFF duty to control the flow rate of fuel vapor from the EVAP canis-
ter. The EVAP canister purge volume control solenoid valve is
moved by ON/OFF pulses from the ECM. The longer the ON pulse,
the greater the amount of fuel vapor that will flow through the valve.
CONSULT-II Reference Value in Data Monitor Mode UBS00HAU
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*
1
EVAP canister
purge flow control
EVAP canister purge vol-
ume control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1
Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
Wheel sensor*
2
Vehicle speed
PBIB2057E
MONITOR ITEM CONDITION SPECIFICATION
PURG VOL C/V
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle
(Accelerator pedal: Not depressed
even slightly, after starting engine)
0%
2,000 rpm —
EC-532
Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
On Board Diagnosis Logic UBS00HAV
DTC Confirmation Procedure UBS00HAW
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Always perform test at a temperature of 5°C (41°F) or more.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Select “PURG VOL CN/V P1444” of “EVAPORATIVE SYSTEM” in “DTC WORK SUPPORT” mode with
CONSULT-II.
5. Touch “START”.
6. Start engine and let it idle until “TESTING” on CONSULT-II changes to “COMPLETED”. (It will take
approximately 10 seconds.)
If “TESTING” is not displayed after 5 minutes, retry from step 2.
7. Make sure that “OK” is displayed after touching “SELF-DIAG RESULTS”. If “NG” is displayed, refer to EC-
535, "Diagnostic Procedure" .
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and let it idle for at least 20 seconds.
4. Select Service $07 with GST.
5. If 1st trip DTC is detected, go to EC-535, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1444
1444
EVAP canister purge
volume control solenoid
valve
The canister purge flow is detected during the
specified driving conditions, even when EVAP
canister purge volume control solenoid valve is
completely closed.
● EVAP control system pressure sensor
● EVAP canister purge volume control
solenoid valve
(The valve is stuck open.)
● EVAP canister vent control valve
● EVAP canister
● Hoses
(Hoses are connected incorrectly or
clogged.)
PBIB0839E
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-533
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Wiring Diagram UBS00HAX
BBWA1687E
EC-534
Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
45 L/Y
EVAP canister purge vol-
ume control solenoid valve
[Engine is running]
● Idle speed
● Accelerator pedal: Not depressed even
slightly, after starting engine
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
● Engine speed: About 2,000 rpm (More than
100 seconds after starting engine)
11 - 14V
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
PBIB0050E
PBIB0051E
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-535
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Diagnostic Procedure UBS00HAY
1. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE POWER SUPPLY CIR-
CUIT
1. Turn ignition switch OFF.
2. Disconnect EVAP canister purge volume control solenoid valve
harness connector.
3. Turn ignition switch ON.
4. Check voltage between EVAP canister purge volume control
solenoid valve terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● IPDM E/R harness connector E119
● Harness for open or short between EVAP canister purge volume control solenoid valve and IPDM E/R
● Harness for open or short between EVAP canister purge volume control solenoid valve and ECM
>> Repair harness or connectors.
3. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE OUTPUT SIGNAL CIR-
CUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 45 and EVAP canister purge volume control solenoid
valve terminal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0366E
Voltage: Battery voltage
PBIB2245E
Continuity should exist.
EC-536
Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
4. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Replace EVAP control system pressure sensor.
5. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK (With CONSULT-II)>>GO TO 6.
OK (Without CONSULT-II)>>GO TO 7.
NG >> Replace EVAP control system pressure sensor.
6. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine.
4. Perform “PURG VOL CONT/V” in “ACTIVE TEST” mode with
CONSULT-II. Check that engine speed varies according to the
valve opening.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7. CHECK EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-538, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP canister purge volume control solenoid valve.
8. CHECK RUBBER TUBE FOR CLOGGING
1. Disconnect rubber tube connected to EVAP canister vent control valve.
2. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 9.
NG >> Clean the rubber tube using an air blower.
9. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-543, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace EVAP canister vent control valve.
Water should not exist.
PBIB1678E
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
EC-537
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10. CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Check if water will drain from the EVAP canister.
Yes or No
Yes >> GO TO 11.
No >> GO TO 13.
11. CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 13.
NG >> GO TO 12.
12. DETECT MALFUNCTIONING PART
Check the following.
● EVAP canister for damage
● EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
13. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
BBIA0351E
EC-538
Revision: October 2005
DTC P1444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
2005 QX56
Component Inspection UBS00HAZ
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
With CONSULT-II
Check air passage continuity of EVAP canister purge volume control
solenoid valve under the following conditions.
Without CONSULT-II
Check air passage continuity of EVAP canister purge volume control
solenoid valve under the following conditions.
Removal and Installation UBS00HB0
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EM-15, "INTAKE MANIFOLD" .
Condition
(PURG VOL CONT/V value)
Air passage continuity
between A and B
100% Yes
0% No
PBIB2058E
Condition
Air passage continuity
between A and B
12V direct current supply between
terminals 1 and 2
Yes
No supply No
PBIB2059E
DTC P1446 EVAP CANISTER VENT CONTROL VALVE
EC-539
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DTC P1446 EVAP CANISTER VENT CONTROL VALVE PFP:14935
Component Description UBS00HB1
The EVAP canister vent control valve is located on the EVAP canis-
ter and is used to seal the canister vent.
This solenoid valve responds to signals from the ECM. When the
ECM sends an ON signal, the coil in the solenoid valve is energized.
A plunger will then move to seal the canister vent. The ability to seal
the vent is necessary for the on board diagnosis of other evaporative
emission control system components.
This solenoid valve is used only for diagnosis, and usually remains
opened.
When the vent is closed, under normal purge conditions, the evapo-
rative emission control system is depressurized and allows EVAP
Control System diagnosis.
CONSULT-II Reference Value in Data Monitor Mode UBS00HB2
Specification data are reference values.
On Board Diagnosis Logic UBS00HB3
PBIB1263E
BBIA0443E
MONITOR ITEM CONDITION SPECIFICATION
VENT CONT/V
● Ignition switch: ON OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1446
1446
EVAP canister vent con-
trol valve close
EVAP canister vent control valve remains
closed under specified driving conditions.
● EVAP canister vent control valve
● EVAP control system pressure sensor
and the circuit
● Blocked rubber tube to EVAP canister
vent control valve
● EVAP canister is saturated with water
EC-540
Revision: October 2005
DTC P1446 EVAP CANISTER VENT CONTROL VALVE
2005 QX56
DTC Confirmation Procedure UBS00HB4
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON and wait at least 5 seconds.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
4. Start engine and let it idle for at least 1 minute.
5. Repeat next procedures 3 times.
a. Increase the engine speed up to 3,000 to 3,500 rpm and keep it
for 2 minutes and 50 seconds to 3 minutes.
Never exceed 3 minutes.
b. Fully released accelerator pedal and keep engine idle for about
5 seconds.
6. If 1st trip DTC is detected, go to EC-542, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to the next step.
7. Repeat next procedure 20 times.
a. Quickly increase the engine speed up to 4,000 to 4,500 rpm or more and keep it for 25 to 30 seconds.
b. Fully released accelerator pedal and keep engine idle for at least 35 seconds.
8. If 1st trip DTC is detected, go to EC-542, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
PBIB0972E
DTC P1446 EVAP CANISTER VENT CONTROL VALVE
EC-541
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Wiring Diagram UBS00HB5
BBWA1688E
EC-542
Revision: October 2005
DTC P1446 EVAP CANISTER VENT CONTROL VALVE
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HB6
1. CHECK RUBBER TUBE
1. Turn ignition switch OFF.
2. Disconnect rubber tube connected to EVAP canister vent control valve.
3. Check the rubber tube for clogging.
OK or NG
OK >> GO TO 2.
NG >> Clean rubber tube using an air blower.
2. CHECK EVAP CANISTER VENT CONTROL VALVE
Refer to EC-543, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace EVAP canister vent control valve.
3. CHECK IF EVAP CANISTER SATURATED WITH WATER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Check if water will drain from the EVAP canister.
Yes or No
Yes >> GO TO 4.
No >> GO TO 6.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
117 L/Y
EVAP canister vent control
valve
[Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
BBIA0443E
BBIA0351E
DTC P1446 EVAP CANISTER VENT CONTROL VALVE
EC-543
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4. CHECK EVAP CANISTER
Weigh the EVAP canister with the EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● EVAP canister for damage
● EVAP hose between EVAP canister and vehicle frame for clogging or poor connection
>> Repair hose or replace EVAP canister.
6. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR CONNECTOR
1. Disconnect EVAP control system pressure sensor harness connector.
2. Check connectors for water.
OK or NG
OK >> GO TO 7.
NG >> Replace EVAP control system pressure sensor.
7. CHECK EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-334, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace EVAP control system pressure sensor.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00HB7
EVAP CANISTER VENT CONTROL VALVE
With CONSULT-II
1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
3. Reconnect harness connectors disconnected.
4. Turn ignition switch ON.
Water should not exist.
PBIB1033E
EC-544
Revision: October 2005
DTC P1446 EVAP CANISTER VENT CONTROL VALVE
2005 QX56
5. Perform “VENT CONTROL/V” in “ACTIVE TEST” mode.
6. Check air passage continuity and operation delay time.
Make sure that new O-ring is installed properly.
Operation takes less than 1 second.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
7. Clean the air passage (Portion A to B ) of EVAP canister vent control valve using an air blower.
8. Perform step 6 again.
Without CONSULT-II
1. Remove EVAP canister vent control valve from EVAP canister.
2. Check portion B of EVAP canister vent control valve for being
rusted.
3. Check air passage continuity and operation delay time under the
following conditions.
Make sure that new O-ring is installed properly.
Operation takes less than 1 second.
If NG, replace EVAP canister vent control valve.
If OK, go to next step.
4. Clean the air passage (Portion A to B ) of EVAP canister vent control valve using an air blower.
5. Perform step 3 again.
Condition VENT CONTROL/V Air passage continuity between A and B
ON No
OFF Yes
PBIB1679E
PBIB1033E
Condition Air passage continuity between A and B
12V direct current supply between
terminals 1 and 2
No
OFF Yes
PBIB1034E
DTC P1564 ICC STEERING SWITCH
EC-545
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DTC P1564 ICC STEERING SWITCH PFP:25551
Component Description UBS00L1M
ICC steering switch has variant values of electrical resistance for each button. ECM reads voltage variation of
switch, and determines which button is operated.
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor Mode UBS00L1N
Specification data are reference values.
On Board Diagnosis Logic UBS00L1O
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to
EC-383, "
DTC P0605 ECM" .
PBIB2640E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW
● Ignition switch: ON
MAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW
● Ignition switch: ON
CANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW
● Ignition switch: ON
RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch:
Released
OFF
SET SW
● Ignition switch: ON
SET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DIST SW
● Ignition switch: ON
DISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
DTC No.
Trouble diagnosis
name
DTC detecting condition Possible cause
P1564
1564
ICC steering switch
● An excessively high voltage signal from the
ICC steering switch is sent to ECM.
● ECM detects that input signal from the ICC
steering switch is out of the specified range.
● ECM detects that the ICC steering switch is
stuck ON.
● Harness or connectors
(The switch circuit is open or shorted.)
● ICC steering switch
● Combination switch (spiral cable)
● ECM
EC-546
Revision: October 2005
DTC P1564 ICC STEERING SWITCH
2005 QX56
DTC Confirmation Procedure UBS00L1P
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 10 seconds.
4. Press MAIN switch for at least 10 seconds, then release it and
wait at least 10 seconds.
5. Press CANCEL switch for at least 10 seconds, then release it
and wait at least 10 seconds.
6. Press RESUME/ACCELERATE switch for at least 10 seconds,
then release it and wait at least 10 seconds.
7. Press SET/COAST switch for at least 10 seconds, then release
it and wait at least 10 seconds.
8. Press DISTANCE switch for at least 10 seconds, then release it
and wait at least 10 seconds.
9. If DTC is detected, go to EC-548, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P1564 ICC STEERING SWITCH
EC-547
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00L1Q
BBWA1785E
EC-548
Revision: October 2005
DTC P1564 ICC STEERING SWITCH
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00L1R
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
99 G/Y ICC steering switch
[Ignition switch: ON]
● ICC steering switch: OFF
Approximately 4.3V
[Ignition switch: ON]
● MAIN switch: Pressed
Approximately 0V
[Ignition switch: ON]
● CANCEL switch: Pressed
Approximately 1.3V
[Ignition switch: ON]
● RESUME/ACCELERATE switch: Pressed
Approximately 3.7V
[Ignition switch: ON]
● SET/COAST switch: Pressed
Approximately 3V
[Ignition switch: ON]
● DISTANCE switch: Pressed
Approximately 2.2V
BBIA0354E
DTC P1564 ICC STEERING SWITCH
EC-549
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2. CHECK ICC STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, “RESUME/ACC SW”, “SET
SW” and “DIST SW” in “DATA MONITOR” mode with CON-
SULT-II.
3. Check each item indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press-
ing each button.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
Switch Monitor item Condition Indication
MAIN switch MAIN SW
Pressed ON
Released OFF
CANCEL switch CANCEL SW
Pressed ON
Released OFF
RESUME/ACCELERATE
switch
RESUME/ACC SW
Pressed ON
Released OFF
SET/COAST switch SET SW
Pressed ON
Released OFF
DISTANCE switch DIST SW
Pressed ON
Released OFF
MBIB0064E
Switch Condition Voltage [V]
MAIN switch
Pressed Approx. 0
Released Approx. 4.3
CANCEL switch
Pressed Approx. 1.3
Released Approx. 4.3
RESUME/ACCELERATE
switch
Pressed Approx. 3.7
Released Approx. 4.3
SET/COAST switch
Pressed Approx. 3.0
Released Approx. 4.3
DISTANCE switch
Pressed Approx. 2.2
Released Approx. 4.3
PBIB0311E
EC-550
Revision: October 2005
DTC P1564 ICC STEERING SWITCH
2005 QX56
3. CHECK ICC STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector.
4. Check harness continuity between combination switch terminal 15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Harness connectors E19, F33
● Combination switch (spiral cable)
● Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK ICC STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Combination switch (spiral cable)
● Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK ICC STEERING SWITCH
Refer to EC-551, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace ICC steering switch.
Continuity should exist.
Continuity should exist.
DTC P1564 ICC STEERING SWITCH
EC-551
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8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00L1S
ICC STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.
2. Check continuity between ICC steering switch terminals 1 and 2
with pushing each switch.
If NG, replace ICC steering switch.
Switch Condition Resistance [Ω]
MAIN switch
Pressed Approx. 0
Released Approx. 5,500
CANCEL switch
Pressed Approx. 310
Released Approx. 5,500
RESUME/ACCELERATE
switch
Pressed Approx. 2,600
Released Approx. 5,500
SET/COAST switch
Pressed Approx. 1,400
Released Approx. 5,500
DISTANCE switch
Pressed Approx. 740
Released Approx. 5,500
PBIB1673E
EC-552
Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
DTC P1564 ASCD STEERING SWITCH PFP:25551
Component Description UBS00L0W
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor Mode UBS00L0X
Specification data are reference values.
On Board Diagnosis Logic UBS00L0Y
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
If DTC P1564 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer to
EC-383, "
DTC P0605 ECM".
PBIB2640E
MONITOR ITEM CONDITION SPECIFICATION
MAIN SW
● Ignition switch: ON
MAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW
● Ignition switch: ON
CANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW
● Ignition switch: ON
RESUME/ACCELERATE switch: Pressed ON
RESUME/ACCELERATE switch: Released OFF
SET SW
● Ignition switch: ON
SET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1564
1564
ASCD steering switch
● An excessively high voltage signal from the ASCD
steering switch is sent to ECM.
● ECM detects that input signal from the ASCD
steering switch is out of the specified range.
● ECM detects that the ASCD steering switch is
stuck ON.
● Harness or connectors
(The switch circuit is open or
shorted.)
● ASCD steering switch
● Combination meter (spiral
cable)
● ECM
DTC P1564 ASCD STEERING SWITCH
EC-553
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DTC Confirmation Procedure UBS00L0Z
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 10 seconds.
4. Press MAIN switch for at least 10 seconds, then release it and wait at least 10 seconds.
5. Press CANCEL switch for at least 10 seconds, then release it and wait at least 10 seconds.
6. Press RESUME/ACCELERATE switch for at least 10 seconds, then release it and wait at least 10 sec-
onds.
7. Press SET/COAST switch for at least 10 seconds, then release it and wait at least 10 seconds.
8. If DTC is detected, go to EC-555, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
EC-554
Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
Wiring Diagram UBS00L10
BBWA2486E
DTC P1564 ASCD STEERING SWITCH
EC-555
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00L11
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
99 G/Y ASCD steering switch
[Ignition switch: ON]
● ASCD steering switch: OFF
Approximately 4V
[Ignition switch: ON]
● MAIN switch: ON
Approximately 0V
[Ignition switch: ON]
● CANCEL switch: ON
Approximately 1V
[Ignition switch: ON]
● RESUME/ACCELERATTTE switch: ON
Approximately 3V
[Ignition switch: ON]
● SET/COAST switch: ON
Approximately 2V
BBIA0354E
EC-556
Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
2. CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “CANCEL SW”, RESUME/ACC SW” and “SET SW” in “DATA MONITOR” mode with
CONSULT-II.
3. Check each item indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press-
ing each button.
OK or NG
OK >> GO TO 8.
NG >> GO TO 3.
3. CHECK ASCD STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination switch harness connector M102.
3. Disconnect ECM harness connector.
4. Check harness continuity between combination switch terminal
15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
Switch Monitor item Condition Indication
MAIN switch MAIN SW
Pressed ON
Released OFF
CANCEL switch CANCEL SW
Pressed ON
Released OFF
RESUME/ACCELERATE
switch
RESUME/ACC SW
Pressed ON
Released OFF
SET/COAST switch SET SW
Pressed ON
Released OFF
SEC006D
Switch Condition Voltage [V]
MAIN switch
Pressed Approx. 0
Released Approx. 4
CANCEL switch
Pressed Approx. 1
Released Approx. 4
RESUME/ACCELERATE
switch
Pressed Approx. 3
Released Approx. 4
SET/COAST switch
Pressed Approx. 2
Released Approx. 4
PBIB0311E
Continuity should exist.
BBIA0362E
DTC P1564 ASCD STEERING SWITCH
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4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Harness connectors E19, F33
● Combination switch (spiral cable)
● Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK ASCD STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Combination switch (spiral cable)
● Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK ASCD STEERING SWITCH
Refer to EC-558, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace ASCD steering switch. Refer to AV-47, "
Removal and Installation of Steering Wheel
Audio Control Switches" .
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
EC-558
Revision: October 2005
DTC P1564 ASCD STEERING SWITCH
2005 QX56
Component Inspection UBS00L12
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102.
2. Check continuity between combination switch (spiral cable) ter-
minals 14 and 15 with pushing each switch.
Switch Condition Resistance [Ω]
MAIN switch
Pressed Approx. 0
Released Approx. 4,000
CANCEL switch
Pressed Approx. 250
Released Approx. 4,000
RESUME/ACCELERATE
switch
Pressed Approx. 1,480
Released Approx. 4,000
SET/COAST switch
Pressed Approx. 660
Released Approx. 4,000
PBIB1673E
DTC P1568 ICC FUNCTION
EC-559
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DTC P1568 ICC FUNCTION PFP:18995
On Board Diagnosis Logic UBS00L1T
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
● If DTC P1568 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
● If DTC P1568 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM".
DTC Confirmation Procedure UBS00L1U
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 4 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch on ICC steering switch.
4. Drive the vehicle at more than 40 km/h (25 MPH).
5. Press SET/COAST switch.
6. If DTC is detected, go to EC-559, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic Procedure UBS00L1V
1. REPLACE ICC UNIT
1. Replace ICC unit.
2. Perform ACS-9, "
ACTION TEST" .
3. Check DTC of ICC unit. Refer to ACS-36, "
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS" .
>> INSPECTION END
DTC No.
Trouble Diagnosis
Name
DTC Detecting Condition Possible Cause
P1568
1568
ICC function
ECM detects a difference between signals
from ICC unit is out of specified range.
● Harness or connectors
(The CAN communication line is open or
shorted.)
● ICC unit
● ECM
SEF058Y
EC-560
Revision: October 2005
DTC P1572 ICC BRAKE SWITCH
2005 QX56
DTC P1572 ICC BRAKE SWITCH PFP:25320
Component Description UBS00L1W
When the brake pedal is depressed, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal).
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor Mode UBS00L1X
Specification data are reference values.
On Board Diagnosis Logic UBS00L1Y
This diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
● If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM" .
● This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
BBIA0470E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW1
(ICC brake switch)
● Ignition switch: ON
Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2
(stop lamp switch)
● Ignition switch: ON
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No.
Trouble diagnosis
name
DTC detecting condition Possible cause
P1572
1572
ICC brake switch
A)
When vehicle speed is above 30 km/h (19
MPH), ON signals from the stop lamp
switch and the ICC brake switch are sent
to ECM at the same time.
● Harness or connectors
(The stop lamp switch circuit is shorted.)
● Harness or connectors
(The ICC brake switch circuit is shorted.)
● Stop lamp switch
● ICC brake switch
● ICC brake hold relay
● Incorrect stop lamp switch installation
● Incorrect ICC brake switch installation
● ECM
B)
ICC brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving
DTC P1572 ICC BRAKE SWITCH
EC-561
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DTC Confirmation Procedure UBS00L1Z
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
● Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
TESTING CONDITION:
Steps 4 and 5 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch and make sure that CRUISE lamp lights up.
4. Drive the vehicle for at least 5 consecutive seconds under the
following conditions.
If 1st trip DTC is detected, go to EC-563, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to the following step.
5. Drive the vehicle for at least 5 consecutive seconds under the following conditions.
6. If 1st trip DTC is detected, go to EC-563, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
PBIB2386E
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location
Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.
EC-562
Revision: October 2005
DTC P1572 ICC BRAKE SWITCH
2005 QX56
Wiring Diagram UBS00L20
BBWA2487E
DTC P1572 ICC BRAKE SWITCH
EC-563
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00L21
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CON-
SULT-II.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch
[Ignition switch: OFF]
● Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
● Brake pedal: Slightly depressed
BATTERY VOLTAGE
(11 - 14V)
108 BR/W ICC brake switch
[Ignition switch: ON]
● Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
● Brake pedal: Fully released
BATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
EC-564
Revision: October 2005
DTC P1572 ICC BRAKE SWITCH
2005 QX56
2. CHECK OVERALL FUNCTION-II
With CONSULT-II
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-II
Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >> GO TO 14.
NG >> GO TO 10.
3. CHECK DTC WITH ICC UNIT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
SEC013D
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
DTC P1572 ICC BRAKE SWITCH
EC-565
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4. CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Turn ignition switch ON.
4. Check voltage between ICC brake hold relay terminal 4 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M4
● 10A fuse
● Harness for open or short between ICC brake hold relay and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check harness continuity between ICC brake hold relay terminal
3 and ICC brake switch terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
BBIA0471E
Voltage: Battery voltage
MBIB0059E
Continuity should exist.
BBIA0470E
EC-566
Revision: October 2005
DTC P1572 ICC BRAKE SWITCH
2005 QX56
7. CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108.
Refer Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK ICC BRAKE HOLD RELAY
Refer to EC-567, "
Component Inspection" .
OK >> GO TO 9.
NG >> Replace ICC brake hold relay.
9. CHECK ICC BRAKE SWITCH
Refer to EC-567, "
Component Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Replace ICC brake switch.
10. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -II or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
Continuity should exist.
BBIA0470E
Voltage: Battery voltage
PBIB2102E
DTC P1572 ICC BRAKE SWITCH
EC-567
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11. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) No. 1 connector M60
● 10A fuse
● Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
13. CHECK STOP LAMP SWITCH
Refer to EC-567, "
Component Inspection"
OK or NG
OK >> GO TO 14.
NG >> Replace stop lamp switch.
14. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00L22
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check continuity between ICC brake switch terminals 1 and 2
under the following conditions.
If NG, adjust ICC brake switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
Continuity should exist.
Condition Continuity
Brake pedal: Fully released. Should exist.
Brake pedal: Slightly depressed. Should not exist.
PBIB1536E
EC-568
Revision: October 2005
DTC P1572 ICC BRAKE SWITCH
2005 QX56
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check continuity between stop lamp switch terminals 3 and 4
under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
ICC BRAKE HOLD RELAY
1. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 4, 6 and 7 under
the following conditions.
3. If NG, replace ICC brake hold relay.
Condition Continuity
Brake pedal: Fully released. Should not exist.
Brake pedal: Slightly depressed. Should exist.
PBIB2103E
Condition Between terminals Continuity
12V direct current supply
between terminals 1 and 2
3 and 4 Should not exist
6 and 7 Should exist
No current supply
3 and 4 Should exist
6 and 7 Should not exist
MBIB0063E
DTC P1572 ASCD BRAKE SWITCH
EC-569
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DTC P1572 ASCD BRAKE SWITCH PFP:25320
Component Description UBS00L13
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)"
for the ASCD function.
CONSULT-II Reference Value in Data Monitor Mode UBS00L14
Specification data are reference values.
On Board Diagnosis Logic UBS00L15
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
● If DTC P 1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM" .
● This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
BBIA0373E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW 1
(ASCD brake switch)
● Ignition switch: ON
Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW 2
(Stop lamp switch)
● Ignition switch: ON
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No.
Trouble Diagnosis
Name
DTC Detecting Condition Possible Cause
P1572
1572
ASCD brake switch
A)
When the vehicle speed is above 30km/h
(19 MPH), ON signals from the stop lamp
switch and the ASCD brake switch are sent
to ECM at the same time.
● Harness or connectors
(The stop lamp switch circuit is shorted.)
● Harness or connectors
(The ASCD brake switch circuit is shorted.)
● Stop lamp switch
● ASCD brake switch
● Incorrect stop lamp switch installation
● Incorrect ASCD brake switch installation
● ECM
B)
ASCD brake switch signal is not sent to
ECM for extremely long time while the vehi-
cle is driving
EC-570
Revision: October 2005
DTC P1572 ASCD BRAKE SWITCH
2005 QX56
DTC confirmation Procedure UBS00L16
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
● If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
● Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
TESTING CONDITION:
Steps 3 and 4 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Press MAIN switch and make sure that CRUISE indicator lights
up.
4. Drive the vehicle for at least 5 consecutive seconds under the
following condition.
If DTC is detected, go to EC-572, "
Diagnostic Procedure" .
If DTC is not detected, go to the following step.
5. Drive the vehicle for at least 5 consecutive seconds under the
following condition.
6. If DTC is detected, go to EC-572, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location
Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned condition.
PBIB2386E
DTC P1572 ASCD BRAKE SWITCH
EC-571
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00L17
BBWA1703E
EC-572
Revision: October 2005
DTC P1572 ASCD BRAKE SWITCH
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00L18
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-II.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch
[Ignition switch: OFF]
● Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
● Brake pedal: Slightly depressed
BATTERY VOLTAGE
(11 - 14V)
108 BR/W ASCD brake switch
[Ignition switch: ON]
● Brake pedal: Fully released
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]
● Brake pedal: Slightly depressed
Approximately 0V
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
DTC P1572 ASCD BRAKE SWITCH
EC-573
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2. CHECK OVERALL FUNCTION-II
With CONSULT-II
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-II
Check voltage between ECM terminal 101 and ground under the following conditions.
OK or NG
OK >> GO TO 11.
NG >> GO TO 7.
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
SEC013D
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
EC-574
Revision: October 2005
DTC P1572 ASCD BRAKE SWITCH
2005 QX56
3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD brake switch terminal 1 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M4
● 10A fuse
● Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ASCD BRAKE SWITCH
Refer to EC-576, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace ASCD brake switch.
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
DTC P1572 ASCD BRAKE SWITCH
EC-575
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7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M60
● 10A fuse
● Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
10. CHECK STOP LAMP SWITCH
Refer to EC-576, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace stop lamp switch.
BBIA0373E
Voltage: Battery voltage
PBIB2102E
Continuity should exist.
EC-576
Revision: October 2005
DTC P1572 ASCD BRAKE SWITCH
2005 QX56
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00L19
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between stop lamp switch terminals 1
and 2 under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
Condition Continuity
Brake pedal: Fully released Should exist.
Brake pedal: Slightly depressed Should not exist.
SEC023D
Condition Continuity
Brake pedal: Fully released Should not exist.
Brake pedal: Slightly depressed Should exist.
PBIB2103E
DTC P1574 ICC VEHICLE SPEED SENSOR
EC-577
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DTC P1574 ICC VEHICLE SPEED SENSOR PFP:31036
Component Description UBS00HZ6
The ECM receives two vehicle speed signals via CAN communication line. One is sent from “unified meter and
A/C amp.”, and the other is from TCM (Transmission control module). The ECM uses these signals for ICC
control. Refer to ACS-6, "
DESCRIPTION" for ICC functions.
On Board Diagnosis Logic UBS00HZ7
● This self-diagnosis has the one trip detection logic.
● The MIL will not light up for this self-diagnosis.
NOTE:
● If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
● If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-372, "
DTC P0500 VSS" .
● If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM" .
DTC Confirmation Procedure UBS00HZ8
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25MPH).
4. If DTC is detected, go to EC-578, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble Diagnosis Name DTC Detecting Condition Possible Cause
P1574
1574
ICC vehicle speed sensor
ECM detects a difference between two vehicle
speed signals is out of the specified range.
● Harness or connectors
(The CAN communication line is open or
shorted.)
● Combination meter
● ABS actuator and electric unit (control unit)
● Wheel sensor
● TCM
● ECM
SEF058Y
EC-578
Revision: October 2005
DTC P1574 ICC VEHICLE SPEED SENSOR
2005 QX56
Diagnostic Procedure UBS00HZ9
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT-37, "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
>> INSPECTION END
DTC P1574 ASCD VEHICLE SPEED SENSOR
EC-579
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DTC P1574 ASCD VEHICLE SPEED SENSOR PFP:31036
Component Description UBS00HBM
The ECM receives two vehicle speed sensor signals via CAN communication line. One is sent from combina-
tion meter and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD
control. Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for ASCD functions.
On Board Diagnosis Logic UBS00HBN
This self-diagnosis has the one trip detection logic.
The MIL will not light up for this diagnosis.
NOTE:
● If DTC P1574 is displayed with DTC U1000, U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN COMMUNICATION LINE" .
● If DTC P1574 is displayed with DTC P0500, first perform the trouble diagnosis for DTC P0500.
Refer to EC-372, "
DTC P0500 VSS".
● If DTC P1574 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605.
Refer to EC-383, "
DTC P0605 ECM".
DTC Confirmation Procedure UBS00HBO
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Step 3 may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road test
is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Drive the vehicle at more than 40 km/h (25 MPH).
4. If DTC is detected, go to EC-580, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.
Trouble Diagnosis
Name
DTC Detecting Condition Possible Cause
P1574
1574
ASCD vehicle speed
sensor
ECM detects a difference between two vehicle
speed signals is out of the specified range.
● Harness or connectors
(The CAN communication line is open or
shorted.)
● Combination meter
● ABS actuator and electric unit (control unit)
● Wheel sensor
● TCM
● ECM
SEF058Y
EC-580
Revision: October 2005
DTC P1574 ASCD VEHICLE SPEED SENSOR
2005 QX56
Diagnostic Procedure UBS00HBP
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT-37, "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK COMBINATION METER FUNCTION
Check combination meter function.
Refer to DI-5, "
COMBINATION METERS" .
>> INSPECTION END
DTC P1706 PNP SWITCH
EC-581
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DTC P1706 PNP SWITCH PFP:32006
Component Description UBS00HBQ
When the gear position is P or N, park/neutral position (PNP) switch is ON.
TCM detects the position because the continuity of the line (the ON signal) exists.
Then the TCM sends the PNP switch signal to the ECM via combination meter.
CONSULT-II Reference Value in Data Monitor Mode UBS00HBR
Specification data are reference values.
On Board Diagnosis Logic UBS00HBS
DTC Confirmation Procedure UBS00HBT
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CON-
SULT-II. Then check the “P/N POSI SW” signal under the follow-
ing conditions.
If NG, go to EC-584, "
Diagnostic Procedure" .
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive sec-
onds.
6. If 1st trip DTC is detected, go to EC-584, "
Diagnostic Procedure" .
MONITOR ITEM CONDITION SPECIFICATION
P/N POSI SW
● Ignition switch: ON
Selector lever: P or N ON
Selector lever: Except above OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1706
1706
Park/neutral position
switch
The signal of the park/neutral position (PNP)
switch is not changed in the process of engine
starting and driving.
● Harness or connectors
[The park/neutral position (PNP) switch
circuit is open or shorted.]
● Park/neutral position (PNP) switch
● Combination meter
● TCM
Position (Selector lever) Known-good signal
N or P position ON
Except the above position OFF
SEF212Y
ENG SPEED More than 1,000 rpm
COOLAN TEMP/S More than 70°C (158°F)
B/FUEL SCHDL More than 2.0 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
SEF213Y
EC-582
Revision: October 2005
DTC P1706 PNP SWITCH
2005 QX56
Overall Function Check UBS00HBU
Use this procedure to check the overall function of the park/neutral position (PNP) switch circuit. During this
check, a 1st trip DTC might not be confirmed.
WITH GST
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 102 (PNP switch signal)
and ground under the following conditions.
3. If NG, go to EC-584, "
Diagnostic Procedure" .
Condition (Gear position) Voltage V (Known-good data)
P or N position Approx. 0
Except the above position
BATTERY VOLTAGE
(11 - 14V)
MBIB0043E
DTC P1706 PNP SWITCH
EC-583
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Wiring Diagram UBS00HBV
BBWA1704E
EC-584
Revision: October 2005
DTC P1706 PNP SWITCH
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HBW
1. CHECK DTC WITH TCM
Refer to AT-37, "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2. CHECK STARTING SYSTEM
Turn ignition switch OFF, then turn it to START.
Does starter motor operate?
Yes or No
Yes >> GO TO 3.
No >> Refer to SC-10, "
STARTING SYSTEM" .
3. CHECK PNP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch OFF.
2. Disconnect A/T assembly harness connector.
3. Disconnect combination meter harness connector.
4. Check harness continuity between A/T assembly terminal 9 and combination meter terminal 39.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors F14, E5
● Harness connectors E152, M31
● Harness for open or short between A/T assembly and combination meter
>> Repair open circuit or short to ground or short to power in harness or connectors.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
102 GR/R PNP switch
[Ignition switch: ON]
● Selector lever: P or N
Approximately 0V
[Ignition switch: ON]
● Except the above gear position
BATTERY VOLTAGE
(11 - 14V)
Continuity should exist.
DTC P1706 PNP SWITCH
EC-585
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5. CHECK PNP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 102 and combination meter terminal 40.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Harness for open or short between ECM and combination meter
>> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK PNP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-III
1. Disconnect TCM harness connector.
2. Check harness continuity between TCM terminal 102 and A/T assembly terminal 9.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace.
9. REPLACE COMBINATION METER
Refer to DI-5, "
COMBINATION METERS" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
EC-586
Revision: October 2005
DTC P1805 BRAKE SWITCH
2005 QX56
DTC P1805 BRAKE SWITCH PFP:25320
Description UBS00HBX
Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.
This signal is used mainly to decrease the engine speed when the vehicle is driving.
CONSULT-II Reference Value in Data Monitor Mode UBS00HBY
Specification data are reference values.
On Board Diagnosis Logic UBS00HBZ
The MIL will not light up for this diagnosis.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode.
DTC Confirmation Procedure UBS00HC0
WITH CONSULT-II
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC with CONSULT-II.
4. Select “DATA MONITOR” mode with CONSULT-II.
5. If 1st trip DTC is detected, go to EC-588, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW
● Ignition switch: ON
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1805
1805
Brake switch
A brake switch signal is not sent to ECM for an
extremely long time while the vehicle is driving.
● Harness or connectors
(Stop lamp switch circuit is open or
shorted.)
● Stop lamp switch
Engine operating condition in fail-safe mode
ECM controls the electric throttle control actuator by regulating the throttle opening to a small range.
Therefore, acceleration will be poor.
Vehicle condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration
SEF058Y
DTC P1805 BRAKE SWITCH
EC-587
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Wiring Diagram UBS00HC1
BBWA1705E
EC-588
Revision: October 2005
DTC P1805 BRAKE SWITCH
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HC2
1. CHECK STOP LAMP SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Check the stop lamp when depressing and releasing the brake pedal.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Disconnect stop lamp switch harness connector.
2. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch
[Ignition switch: OFF]
● Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
● Brake pedal: Slightly depressed
BATTERY VOLTAGE
(11 - 14V)
Brake pedal Stop lamp
Fully released Not illuminated
Slightly depressed Illuminated
BBIA0373E
Voltage: Battery voltage
PBIB2102E
DTC P1805 BRAKE SWITCH
EC-589
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3. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M60
● 10A fuse
● Harness for open and short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK STOP LAMP SWITCH
Refer to EC-590, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace stop lamp switch.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
EC-590
Revision: October 2005
DTC P1805 BRAKE SWITCH
2005 QX56
Component Inspection UBS00HC3
STOP LAMP SWITCH
1. Disconnect stop lamp switch harness connector.
2. Check continuity between stop lamp switch terminals 3 and 4
under the following conditions.
3. If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 2 again.
BBIA0373E
Conditions Continuity
Brake pedal: Fully released Should not exist.
Brake pedal: Slightly depressed Should exist.
PBIB2103E
DTC P2122, P2123 APP SENSOR
EC-591
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DTC P2122, P2123 APP SENSOR PFP:18002
Component Description UBS00HC4
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor Mode UBS00HC5
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis Logic UBS00HC6
These self-diagnoses have the one trip detection logic.
NOTE:
If DTC P2122 or P2123 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229.
Refer to EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
CLSD THL POS
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2122
2122
Accelerator pedal position
sensor 1 circuit low input
An excessively low voltage from the APP sen-
sor 1 is sent to ECM.
● Harness or connectors
(The APP sensor 1 circuit is open or
shorted.)
● Accelerator pedal position sensor
(Accelerator pedal position sensor 1)
P2123
2123
Accelerator pedal position
sensor 1 circuit high input
An excessively high voltage from the APP sen-
sor 1 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
EC-592
Revision: October 2005
DTC P2122, P2123 APP SENSOR
2005 QX56
DTC Confirmation Procedure UBS00HC7
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-594, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P2122, P2123 APP SENSOR
EC-593
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Wiring Diagram UBS00HC8
BBWA1706E
EC-594
Revision: October 2005
DTC P2122, P2123 APP SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HC9
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
82 B/R
Sensor ground
(APP sensor 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
83 G/W
Sensor ground
(APP sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
90 L
Sensor power supply
(APP sensor 1)
[Ignition switch: ON] Approximately 5V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
98 G/R
Accelerator pedal position
sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.25 - 0.50V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
2.0 - 2.5V
106 BR/W
Accelerator pedal position
sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
4.2 - 4.8V
BBIA0354E
DTC P2122, P2123 APP SENSOR
EC-595
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2. CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 7 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. CHECK APP SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 82 and APP sensor terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 106 and APP sensor terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK APP SENSOR
Refer to EC-596, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
BBIA0361E
Voltage: Approximately 5V
PBIB2070E
Continuity should exist.
Continuity should exist.
EC-596
Revision: October 2005
DTC P2122, P2123 APP SENSOR
2005 QX56
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00HCA
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig-
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-90, "
Throttle Valve Closed Position Learning" .
7. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00HCB
ACCELERATOR PEDAL
Refer to ACC-2, "ACCELERATOR CONTROL SYSTEM" .
Terminal Accelerator pedal Voltage
106
(Accelerator pedal position
sensor 1)
Fully released 0.5 - 1.0V
Fully depressed 4.2 - 4.8V
98
(Accelerator pedal position
sensor 2)
Fully released 0.25 - 0.5V
Fully depressed 2.0 - 2.5V
MBIB0023E
DTC P2127, P2128 APP SENSOR
EC-597
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Revision: October 2005 2005 QX56
DTC P2127, P2128 APP SENSOR PFP:18002
Component Description UBS00HCC
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor Mode UBS00HCD
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis Logic UBS00HCE
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
CLSD THL POS
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2127
2127
Accelerator pedal position
sensor 2 circuit low input
An excessively low voltage from the APP
sensor 2 is sent to ECM.
● Harness or connectors
(APP sensor 2 circuit is open or shorted.)
(TP sensor circuit is shorted.)
● Accelerator pedal position sensor
(Accelerator pedal position sensor 2)
● Electric throttle control actuator
(TP sensor)
P2128
2128
Accelerator pedal position
sensor 2 circuit high input
An excessively high voltage from the APP
sensor 2 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
EC-598
Revision: October 2005
DTC P2127, P2128 APP SENSOR
2005 QX56
DTC Confirmation Procedure UBS00HCF
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-600, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P2127, P2128 APP SENSOR
EC-599
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00HCG
BBWA1707E
EC-600
Revision: October 2005
DTC P2127, P2128 APP SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HCH
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
47 Y
Sensor power supply
(TP sensor)
[Ignition switch: ON] Approximately 5V
82 B/R
Sensor ground
(APP sensor 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
83 G/W
Sensor ground
(APP sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
90 L
Sensor power supply
(APP sensor 1)
[Ignition switch: ON] Approximately 5V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
98 G/R
Accelerator pedal position
sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.25 - 0.50V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
2.0 - 2.5V
106 BR/W
Accelerator pedal position
sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
4.2 - 4.8V
BBIA0354E
DTC P2127, P2128 APP SENSOR
EC-601
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Revision: October 2005 2005 QX56
2. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 6 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between APP sensor terminal 6 and ECM terminal 91.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace open circuit.
4. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5. CHECK THROTTLE POSITION SENSOR
Refer to EC-610, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
BBIA0361E
Voltage: Approximately 5V
PBIB2069E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-606
91 APP sensor terminal 6 EC-599
EC-602
Revision: October 2005
DTC P2127, P2128 APP SENSOR
2005 QX56
6. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK APP SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 83 and APP sensor terminal 3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK APP SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 98 and APP sensor terminal 5.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK APP SENSOR
Refer to EC-603, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
DTC P2127, P2128 APP SENSOR
EC-603
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Revision: October 2005 2005 QX56
Component Inspection UBS00HCI
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig-
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-90, "
Throttle Valve Closed Position Learning" .
7. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00HCJ
ACCELERATOR PEDAL
Refer to ACC-2, "ACCELERATOR CONTROL SYSTEM" .
Terminal Accelerator pedal Voltage
106
(Accelerator pedal position
sensor 1)
Fully released 0.5 - 1.0V
Fully depressed 4.2 - 4.8V
98
(Accelerator pedal position
sensor 2)
Fully released 0.25 - 0.5V
Fully depressed 2.0 - 2.5V
MBIB0023E
EC-604
Revision: October 2005
DTC P2135 TP SENSOR
2005 QX56
DTC P2135 TP SENSOR PFP:16119
Component Description UBS00HCK
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
CONSULT-II Reference Value in Data Monitor Mode UBS00HCL
Specification data are reference values.
*: Throttle position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage signal.
On Board Diagnosis Logic UBS00HCM
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
PBIB0145E
MONITOR ITEM CONDITION SPECIFICATION
THRTL SEN 1
THRTL SEN 2*
● Ignition switch: ON
(Engine stopped)
● Selector lever: D
Accelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2135
2135
Throttle position sensor
circuit range/performance
problem
Rationally incorrect voltage is sent to ECM
compared with the signals from TP sensor 1
and TP sensor 2.
● Harness or connector
(TP sensor 1 and 2 circuit is open or
shorted.)
(APP sensor 2 circuit is shorted.)
● Electric throttle control actuator
(TP sensor 1 and 2)
● Accelerator pedal position sensor
Engine operation condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
DTC P2135 TP SENSOR
EC-605
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Revision: October 2005 2005 QX56
DTC Confirmation Procedure UBS00HCN
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-607, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
EC-606
Revision: October 2005
DTC P2135 TP SENSOR
2005 QX56
Wiring Diagram UBS00HCO
BBWA1708E
DTC P2135 TP SENSOR
EC-607
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HCP
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
47 Y
Sensor power supply
(Throttle position sensor)
[Ignition switch: ON] Approximately 5V
50 B Throttle position sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
More than 0.36V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
Less than 4.75V
66 R
Sensor ground
(Throttle position sensor)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
69 W Throttle position sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
● Engine: Stopped
● Selector lever: D
● Accelerator pedal: Fully depressed
More than 0.36V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
BBIA0354E
EC-608
Revision: October 2005
DTC P2135 TP SENSOR
2005 QX56
2. CHECK THROTTLE POSITION SENSOR POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator terminal
2 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3. CHECK THROTTLE POSITION SENSOR POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 2 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace open circuit.
4. CHECK THROTTLE POSITION SENSOR POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5. CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-618, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
BBIA0371E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-606
91 APP sensor terminal 6 EC-613
DTC P2135 TP SENSOR
EC-609
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Revision: October 2005 2005 QX56
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
7. CHECK THROTTLE POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric throttle control actuator terminal 4 and ECM terminal 66.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK THROTTLE POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 50 and electric throttle control actuator terminal 1, ECM
terminal 69 and electric throttle control actuator terminal 3.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK THROTTLE POSITION SENSOR
Refer to EC-610, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
Continuity should exist.
EC-610
Revision: October 2005
DTC P2135 TP SENSOR
2005 QX56
Component Inspection UBS00HCQ
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Turn ignition switch ON.
4. Set selector lever to D position.
5. Check voltage between ECM terminals 50 (TP sensor 1 signal),
69 (TP sensor 2 signal) and ground under the following condi-
tions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. Perform EC-90, "
Throttle Valve Closed Position Learning" .
8. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00HCR
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-15, "INTAKE MANIFOLD" .
Terminal Accelerator pedal Voltage
50
(Throttle position sensor 1)
Fully released More than 0.36V
Fully depressed Less than 4.75V
69
(Throttle position sensor 2)
Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB1530E
DTC P2138 APP SENSOR
EC-611
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Revision: October 2005 2005 QX56
DTC P2138 APP SENSOR PFP:18002
Component Description UBS00HCS
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor Mode UBS00HCT
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis Logic UBS00HCU
This self-diagnosis has the one trip detection logic.
NOTE:
If DTC P2138 is displayed with DTC P1229, first perform the trouble diagnosis for DTC P1229. Refer to
EC-454, "
DTC P1229 SENSOR POWER SUPPLY" .
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
CLSD THL POS
● Ignition switch: ON
(Engine stopped)
Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2138
2138
Accelerator pedal position
sensor circuit range/per-
formance problem
Rationally incorrect voltage is sent to ECM
compared with the signals from APP sensor 1
and APP sensor 2.
● Harness or connector
(APP sensor 1 and 2 circuit is open or
shorted.)
(TP sensor circuit is shorted.)
● Accelerator pedal position sensor 1 and 2
● Electric throttle control actuator
(TP sensor)
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.
EC-612
Revision: October 2005
DTC P2138 APP SENSOR
2005 QX56
DTC Confirmation Procedure UBS00HCV
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-614, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y
DTC P2138 APP SENSOR
EC-613
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00HCW
BBWA1709E
EC-614
Revision: October 2005
DTC P2138 APP SENSOR
2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HCX
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
47 Y
Sensor power supply
(TP sensor)
[Ignition switch: ON] Approximately 5V
82 B/R
Sensor ground
(APP sensor 1)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
83 G/W
Sensor ground
(APP sensor 2)
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
90 L
Sensor power supply
(APP sensor 1)
[Ignition switch: ON] Approximately 5V
91 W/R
Sensor power supply
(APP sensor 2)
[Ignition switch: ON] Approximately 5V
98 G/R
Accelerator pedal position
sensor 2
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.25 - 0.50V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
2.0 - 2.5V
106 BR/W
Accelerator pedal position
sensor 1
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
● Engine: Stopped
● Accelerator pedal: Fully depressed
4.2 - 4.8V
BBIA0354E
DTC P2138 APP SENSOR
EC-615
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Revision: October 2005 2005 QX56
2. CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 7 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ON.
2. Check voltage between APP sensor terminal 6 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 4.
4. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between APP sensor terminal 6 and ECM terminal 91.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit in harness or connectors.
BBIA0361E
Voltage: Approximately 5V
PBIB2070E
Voltage: Approximately 5V
PBIB2069E
Continuity should exist.
EC-616
Revision: October 2005
DTC P2138 APP SENSOR
2005 QX56
5. CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals
OK or NG
OK >> GO TO 6.
NG >> Repair short to ground or short to power in harness connectors.
6. CHECK THROTTLE POSITION SENSOR
Refer to EC-610, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 7.
7. REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-90, "
Throttle Valve Closed Position Learning" .
3. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
8. CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 82 and APP sensor terminal 1, ECM terminal 83 and
APP sensor terminal 3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 106 and APP sensor terminal 2, ECM terminal 98 and
APP sensor terminal 5.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-606
91 APP sensor terminal 6 EC-613
Continuity should exist.
Continuity should exist.
DTC P2138 APP SENSOR
EC-617
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10. CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-618, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-90, "
Throttle Valve Closed Position Learning" .
4. Perform EC-91, "
Idle Air Volume Learning" .
>> INSPECTION END
12. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
EC-618
Revision: October 2005
DTC P2138 APP SENSOR
2005 QX56
Component Inspection UBS00HCY
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig-
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-90, "
Accelerator Pedal Released Position Learning" .
6. Perform EC-90, "
Throttle Valve Closed Position Learning" .
7. Perform EC-91, "
Idle Air Volume Learning" .
Removal and Installation UBS00HCZ
ACCELERATOR PEDAL
Refer to ACC-2, "ACCELERATOR CONTROL SYSTEM" .
Terminal Accelerator pedal Voltage
106
(Accelerator pedal position
sensor 1)
Fully released 0.5 - 1.0V
Fully depressed 4.2 - 4.8V
98
(Accelerator pedal position
sensor 2)
Fully released 0.25 - 0.5V
Fully depressed 2.0 - 2.5V
MBIB0023E
IGNITION SIGNAL
EC-619
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IGNITION SIGNAL PFP:22448
Component Description UBS00L1A
IGNITION COIL & POWER TRANSISTOR
The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns
ON and OFF the ignition coil primary circuit. This ON/OFF operation induces the proper high voltage in the coil
secondary circuit.
BBIA0359E
EC-620
Revision: October 2005
IGNITION SIGNAL
2005 QX56
Wiring Diagram UBS00L1B
BBWA1710E
IGNITION SIGNAL
EC-621
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
111 W/B
ECM relay
(Self shut-off)
[Engine is running]
[Ignition switch: OFF]
● For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]
● More than a few seconds after turning igni-
tion switch OFF
BATTERY VOLTAGE
(11 - 14V)
119
120
BR
BR
Power supply for ECM [Ignition switch: ON]
BATTERY VOLTAGE
(11 - 14V)
EC-622
Revision: October 2005
IGNITION SIGNAL
2005 QX56
BBWA2488E
IGNITION SIGNAL
EC-623
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
46
60
61
62
L/R
GR/R
O/W
Y/R
Ignition signal No. 7
Ignition signal No. 5
Ignition signal No. 3
Ignition signal No. 1
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.
0 - 0.2V
[Engine is running]
● Warm-up condition
● Engine speed: 2,000 rpm.
0.1 - 0.4V
PBIB0044E
PBIB0045E
EC-624
Revision: October 2005
IGNITION SIGNAL
2005 QX56
BBWA1712E
IGNITION SIGNAL
EC-625
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00L1C
1. CHECK ENGINE START
Turn ignition switch OFF, and restart engine.
Is engine running?
Yes or No
Yes (With CONSULT-II)>>GO TO 2.
Yes (Without CONSULT-II)>>GO TO 3.
No >> GO TO 4.
2. CHECK OVERALL FUNCTION
With CONSULT-II
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
2. Make sure that each circuit produces a momentary engine
speed drop.
OK or NG
OK >> INSPECTION END
NG >> GO TO 10.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
65
79
80
81
G/R
V/W
W/R
W/G
Ignition signal No. 8
Ignition signal No. 6
Ignition signal No. 4
Ignition signal No. 2
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle.
0 - 0.2V
[Engine is running]
● Warm-up condition
● Engine speed: 2,000 rpm.
0.1 - 0.4V
PBIB0044E
PBIB0045E
PBIB0133E
EC-626
Revision: October 2005
IGNITION SIGNAL
2005 QX56
3. CHECK OVERALL FUNCTION
Without CONSULT-II
1. Let engine idle.
2. Read the voltage signal between ECM terminals 46, 60, 61, 62,
65, 79, 80, 81 and ground with an oscilloscope.
3. Verify that the oscilloscope screen shows the signal wave as
shown below.
NOTE:
The pulse cycle changes depending on rpm at idle.
OK or NG
OK >> INSPECTION END
NG >> GO TO 10.
4. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
2. Check voltage between ECM terminals 119, 120 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> Go to EC-157, "
POWER SUPPLY AND GROUND CIR-
CUIT" .
PBIB2094E
PBIB0044E
Voltage: Battery voltage
MBIB0034E
IGNITION SIGNAL
EC-627
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5. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Turn ignition switch ON.
4. Check voltage between condenser terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector E119.
3. Check harness continuity between IPDM E/R terminal 4 and condenser terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> Go to EC-157, "POWER SUPPLY AND GROUND CIRCUIT" .
NG >> GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between ignition coil and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0358E
Voltage: Battery voltage
PBIB0624E
Continuity should exist.
EC-628
Revision: October 2005
IGNITION SIGNAL
2005 QX56
8. CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between condenser terminal 2 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to power in harness or connectors.
9. CHECK CONDENSER
Refer to EC-629, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace condenser.
10. CHECK IGNITION COIL POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Disconnect ignition coil harness connector.
4. Turn ignition switch ON.
5. Check voltage between ignition coil terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● Harness for open or short between ignition coil and harness connector F32
>> Repair or replace harness or connectors.
Continuity should exist.
Voltage: Battery voltage
BBIA0359E
PBIB0138E
IGNITION SIGNAL
EC-629
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12. CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between ignition coil terminal 2 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to power in harness or connectors.
13. CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 46, 60, 61, 62, 65, 79, 80, 81 and ignition coil terminal
1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14. CHECK IGNITION COIL WITH POWER TRANSISTOR
Refer to EC-629, "
Component Inspection" .
OK or NG
OK >> GO TO 15.
NG >> Replace ignition coil with power transistor.
15. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00L1D
IGNITION COIL WITH POWER TRANSISTOR
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Disconnect ignition coil harness connector.
3. Check resistance between ignition coil terminals as follows.
4. If NG, replace ignition coil with power transistor.
If OK, go to next step.
5. Turn ignition switch OFF.
6. Reconnect all harness connectors disconnected.
Continuity should exist.
Continuity should exist.
Terminal No. (Polarity) Resistance Ω [at 25°C (77°F)]
1 and 2 Except 0 or ∞
1 and 3
Except 0
2 and 3
PBIB0847E
EC-630
Revision: October 2005
IGNITION SIGNAL
2005 QX56
7. Remove fuel pump fuse in fuse block No. 1 to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
8. Start engine.
9. After engine stalls, crank it two or three times to release all fuel
pressure.
10. Turn ignition switch OFF.
11. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
12. Remove ignition coil and spark plug of the cylinder to be checked.
13. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
14. Connect spark plug and harness connector to ignition coil.
15. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
16. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
● Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
● It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
17. If NG, replace ignition coil with power transistor.
CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Check resistance between condenser terminals 1 and 2.
Removal and Installation UBS00L1E
IGNITION COIL WITH POWER TRANSISTOR
Refer to EM-26, "IGNITION COIL" .
Spark should be generated.
BBIA0380E
PBIB2325E
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E
INJECTOR CIRCUIT
EC-631
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INJECTOR CIRCUIT PFP:16600
Component Description UBS00L1F
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the injector circuit, the coil in the injector is
energized. The energized coil pulls the ball valve back and allows
fuel to flow through the injector into the intake manifold. The amount
of fuel injected depends upon the injection pulse duration. Pulse
duration is the length of time the injector remains open. The ECM
controls the injection pulse duration based on engine fuel needs.
CONSULT-II Reference Value in Data Monitor Mode UBS00L1G
Specification data are reference values.
SEF375Z
MONITOR ITEM CONDITION SPECIFICATION
B/FUEL SCHDL See EC-146, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
INJ PULSE-B1
INJ PULSE-B2
● Engine: After warming up
● Air conditioner switch: OFF
● Selector lever: P or N
● No load
Idle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
EC-632
Revision: October 2005
INJECTOR CIRCUIT
2005 QX56
Wiring Diagram UBS00L1H
BBWA1713E
INJECTOR CIRCUIT
EC-633
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic Procedure UBS00L1I
1. INSPECTION START
Turn ignition switch to START.
Is any cylinder ignited?
Yes or No
Yes >> GO TO 2.
No >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
21
22
23
40
41
42
44
63
O/L
BR
GR/W
Y/G
P
L
O
G
Injector No. 5
Injector No. 3
Injector No. 1
Injector No. 6
Injector No. 4
Injector No. 2
Injector No. 7
Injector No. 8
[Engine is running]
● Warm-up condition
● Idle speed
NOTE:
The pulse cycle changes depending on rpm at idle.
BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
● Warm-up condition
● Engine speed: 2,000 rpm
BATTERY VOLTAGE
(11 - 14V)
PBIB0042E
PBIB0043E
EC-634
Revision: October 2005
INJECTOR CIRCUIT
2005 QX56
2. CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
Clicking noise should be heard.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
PBIB0133E
PBIB1986E
INJECTOR CIRCUIT
EC-635
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3. CHECK INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between injector terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E2, F32
● IPDM E/R connector E119
● 15A fuse
● Harness for open or short between injector and fuse
>> Repair harness or connectors.
5. CHECK INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.
EC-636
Revision: October 2005
INJECTOR CIRCUIT
2005 QX56
6. CHECK INJECTOR
Refer to EC-636, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace injector.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00L1J
INJECTOR
1. Disconnect injector harness connector.
2. Check resistance between terminals as shown in the figure.
Removal and Installation UBS00L1K
INJECTOR
Refer to EM-29, "FUEL INJECTOR AND FUEL TUBE" .
Resistance: 11.1 - 14.5Ω [at 10 - 60°C (50 - 140°F)]
PBIB1727E
FUEL PUMP CIRCUIT
EC-637
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FUEL PUMP CIRCUIT PFP:17042
Description UBS00HDB
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
CONSULT-II Reference Value in Data Monitor Mode UBS00HDC
Specification data are reference values.
Sensor Input signal to ECM ECM Function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Stops.
BBIA0402E
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLY
● For 1 second after turning ignition switch ON
● Engine running or cranking
ON
● Except above conditions OFF
EC-638
Revision: October 2005
FUEL PUMP CIRCUIT
2005 QX56
Wiring Diagram UBS00HDD
BBWA1714E
FUEL PUMP CIRCUIT
EC-639
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EC
Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HDE
1. CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
4. Check voltage between ECM terminal 113 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
113 GR Fuel pump relay
[Ignition switch: ON]
● For 1 second after turning ignition switch ON
[Engine is running]
0 - 1.5V
[Ignition switch: ON]
● More than 1 second after turning ignition
switch ON.
BATTERY VOLTAGE
(11 - 14V)
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after ignition switch is turned ON.
BBIA0357E
Voltage: Battery voltage
PBIB1187E
EC-640
Revision: October 2005
FUEL PUMP CIRCUIT
2005 QX56
3. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R harness connector E122.
3. Turn ignition switch ON.
4. Check voltage between IPDM E/R terminal 46 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 13.
4. DETECT MALFUNCTIONING PART
Check harness for open or short between IPDM E/R and ECM.
>> Repair harness or connectors.
5. CHECK CONDENSER POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Disconnect condenser harness connector.
4. Turn ignition switch ON.
5. Check voltage between condenser terminal 1 and ground with
CONSULT-II or tester.
6. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
Voltage: Battery voltage
PBIB2084E
BBIA0388E
Voltage: Battery voltage should exist for 1 sec-
ond after ignition switch is turned ON.
PBIB0624E
FUEL PUMP CIRCUIT
EC-641
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6. CHECK 15A FUSE
1. Turn ignition switch OFF.
2. Disconnect 15A fuse.
3. Check 15A fuse.
OK or NG
OK >> GO TO 7.
NG >> Replace fuse.
7. CHECK CONDENSER POWER SUPPLY CIRCUIT-II FOR OPEN AND SHORT
1. Disconnect IPDM E/R harness connector E119.
2. Check harness continuity between IPDM E/R terminal 13 and condenser terminal 1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between condenser terminal 2 and ground.
Refer to Wiring Diagram.
2. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to power in harness or connectors.
9. CHECK CONDENSER
Refer to EC-642, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace condenser.
10. CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
3. Disconnect IPDM E/R harness connector E119.
4. Check harness continuity between IPDM E/R terminal 13 and
“fuel level sensor unit and fuel pump” terminal 1, “fuel level sen-
sor unit and fuel pump” terminal 3 and ground.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
Continuity should exist.
Continuity should exist.
Continuity should exist.
BBIA0583E
EC-642
Revision: October 2005
FUEL PUMP CIRCUIT
2005 QX56
11. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E41, C1
● Harness for open or short between fuel pump and IPDM E/R
● Harness for open or short between fuel pump and ground
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK FUEL PUMP
Refer to EC-642, "
Component Inspection" .
OK or NG
OK >> GO TO 13.
NG >> Replace “fuel level sensor unit and fuel pump”.
13. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair or replace harness or connectors.
Component Inspection UBS00HDF
FUEL PUMP
1. Disconnect “fuel level sensor unit and fuel pump” harness connector.
2. Check resistance between fuel level sensor unit and fuel pump
terminals 1 and 3.
CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Check resistance between condenser terminals as 1 and 2.
Removal and Installation UBS00HDG
FUEL PUMP
Refer to FL-5, "FUEL LEVEL SENSOR UNIT, FUEL FILTER AND FUEL PUMP ASSEMBLY" .
Resistance: 0.2 - 5.0Ω [at 25°C (77°F)]
SEC918C
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E
REFRIGERANT PRESSURE SENSOR
EC-643
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Revision: October 2005 2005 QX56
REFRIGERANT PRESSURE SENSOR PFP:92136
Component Description UBS00HDH
The refrigerant pressure sensor is installed at the liquid tank of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan system.
BBIA0445E
SEF099XA
EC-644
Revision: October 2005
REFRIGERANT PRESSURE SENSOR
2005 QX56
Wiring Diagram UBS00HDI
BBWA1715E
REFRIGERANT PRESSURE SENSOR
EC-645
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HDJ
1. CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2. CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
49 R/Y
Sensor power supply
(Refrigerant pressure sen-
sor)
[Ignition switch: ON] Approximately 5V
67 B Sensor ground
[Engine is running]
● Warm-up condition
● Idle speed
Approximately 0V
70 B/W Refrigerant pressure sensor
[Engine is running]
● Warm-up condition
● Both A/C switch and blower switch: ON
(Compressor: Operates)
1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB1188E
BBIA0354E
EC-646
Revision: October 2005
REFRIGERANT PRESSURE SENSOR
2005 QX56
3. CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect refrigerant pressure sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between refrigerant pressure sensor terminal 1
and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● Harness for open or short between ECM and refrigerant pressure sensor
>> Repair harness or connectors.
5. CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between refrigerant pressure sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0445E
Voltage: Approximately 5V
PBIB0188E
Continuity should exist.
REFRIGERANT PRESSURE SENSOR
EC-647
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7. CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 70 and refrigerant pressure sensor terminal 2.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors E5, F14
● Harness for open or short between ECM and refrigerant pressure sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace refrigerant pressure sensor.
NG >> Repair or replace.
Removal and Installation UBS00HDK
REFRIGERANT PRESSURE SENSOR
Refer to ATC-185, "Removal and Installation for Refrigerant Pressure Sensor" .
Continuity should exist.
EC-648
Revision: October 2005
ELECTRICAL LOAD SIGNAL
2005 QX56
ELECTRICAL LOAD SIGNAL PFP:25350
Description UBS00HDL
The electrical load signal (Headlamp switch signal, rear window defogger switch signal, etc.) is transferred
through the CAN communication line from BCM to ECM via IPDM E/R.
CONSULT-II Reference Value in Data Monitor Mode UBS00HDM
Specification data are reference values.
Diagnostic Procedure UBS00HDN
1. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
1. Turn ignition switch ON.
2. Connect CONSULT-II and select “DATA MONITOR” mode.
3. Select “LOAD SIGNAL” and check indication under the following
conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Check “LOAD SIGNAL” indication under the following conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 4.
3. CHECK REAR WINDOW DEFOGGER SYSTEM
Refer to GW-77, "
REAR WINDOW DEFOGGER" .
>> INSPECTION END
4. CHECK HEADLAMP SYSTEM
Refer to LT-6, "
HEADLAMP (FOR USA)" , or LT-33, "HEADLAMP (FOR CANADA) - DAYTIME LIGHT SYS-
TEM -" .
>> INSPECTION END
MONITOR ITEM CONDITION SPECIFICATION
LOAD SIGNAL
● Ignition switch: ON
Rear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF.
OFF
Condition Indication
Rear window defogger switch: ON ON
Rear window defogger switch: OFF OFF
PBIB0103E
Condition Indication
Lighting switch: ON at 2nd position ON
Lighting switch: OFF OFF
PBIB0103E
ICC BRAKE SWITCH
EC-649
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Revision: October 2005 2005 QX56
ICC BRAKE SWITCH PFP:25320
Component Description UBS00L23
When depress on the brake pedal, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal)
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor Mode UBS00L24
Specification data are reference values.
BBIA0470E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW 1
(ICC brake switch)
● Ignition switch: ON
Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW 2
(Stop lamp switch)
● Ignition switch: ON
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
EC-650
Revision: October 2005
ICC BRAKE SWITCH
2005 QX56
Wiring Diagram UBS00L25
BBWA1786E
ICC BRAKE SWITCH
EC-651
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Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00L26
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CON-
SULT-II.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch
[Ignition switch: OFF]
● Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
● Brake pedal: Slightly depressed
BATTERY VOLTAGE
(11 - 14V)
108 BR/W ICC brake switch
[Ignition switch: ON]
● Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
● Brake pedal: Fully released
BATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
EC-652
Revision: October 2005
ICC BRAKE SWITCH
2005 QX56
2. CHECK OVERALL FUNCTION-II
With CONSULT-II
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-II
Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 10.
3. CHECK DTC WITH ICC UNIT
Refer to ACS-36, "
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
SEC013D
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
ICC BRAKE SWITCH
EC-653
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4. CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Turn ignition switch ON.
4. Check voltage between ICC brake hold relay terminal 4 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M4
● 10A fuse
● Harness for open or short between ICC brake hold relay and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check harness continuity between ICC brake hold relay terminal
3 and ICC brake switch terminal 1.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
BBIA0471E
Voltage: Battery voltage
MBIB0059E
Continuity should exist.
BBIA0470E
EC-654
Revision: October 2005
ICC BRAKE SWITCH
2005 QX56
7. CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108.
Refer Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK ICC BRAKE HOLD RELAY
Refer to EC-656, "
Component Inspection" .
OK >> GO TO 9.
NG >> Replace ICC brake hold relay.
9. CHECK ICC BRAKE SWITCH
Refer to EC-656, "
Component Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Replace ICC brake switch.
10. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -II or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
Continuity should exist.
BBIA0470E
Voltage: Battery voltage
PBIB2102E
ICC BRAKE SWITCH
EC-655
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11. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) No. 1 connector M60
● 10A fuse
● Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
12. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
13. CHECK STOP LAMP SWITCH
Refer to EC-656, "
Component Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Replace stop lamp switch.
14. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Continuity should exist.
EC-656
Revision: October 2005
ICC BRAKE SWITCH
2005 QX56
Component Inspection UBS00L27
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check continuity between ICC brake switch terminals 1 and 2
under the following conditions.
If NG, adjust ICC brake switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check continuity between stop lamp switch terminals 3 and 4
under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
ICC BRAKE HOLD RELAY
1. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 4, 6 and 7 under
the following conditions.
3. If NG, replace ICC brake hold relay.
Condition Continuity
Brake pedal: Fully released. Should exist.
Brake pedal: Slightly depressed. Should not exist.
PBIB1536E
Condition Continuity
Brake pedal: Fully released. Should not exist.
Brake pedal: Slightly depressed. Should exist.
PBIB2103E
Condition Between terminals Continuity
12V direct current supply
between terminals 1 and 2
3 and 4 Should not exist
6 and 7 Should exist
No current supply
3 and 4 Should exist
6 and 7 Should not exist
MBIB0063E
ASCD BRAKE SWITCH
EC-657
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Revision: October 2005 2005 QX56
ASCD BRAKE SWITCH PFP:25320
Component Description UBS00HDO
When the brake pedal is depressed, ASCD brake switch is turned
OFF and stop lamp switch is turned ON. ECM detects the state of
the brake pedal by this input of two kinds (ON/OFF signal).
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)"
for the ASCD function.
CONSULT-II Reference Value in Data Monitor Mode UBS00HDP
Specification data are reference values.
BBIA0373E
MONITOR ITEM CONDITION SPECIFICATION
BRAKE SW 1
(ASCD brake switch)
● Ignition switch: ON
● Brake pedal: Fully released ON
● Brake pedal: Slightly depressed OFF
BRAKE SW 2
(Stop lamp switch)
● Ignition switch: ON
● Brake pedal: Fully released OFF
● Brake pedal: Slightly depressed ON
EC-658
Revision: October 2005
ASCD BRAKE SWITCH
2005 QX56
Wiring Diagram UBS00HDQ
BBWA1716E
ASCD BRAKE SWITCH
EC-659
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EC
Revision: October 2005 2005 QX56
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic Procedure UBS00HDR
1. CHECK OVERALL FUNCTION-I
With CONSULT-II
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-II.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
TER-
MINAL
NO.
WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
101 R/W Stop lamp switch
[Ignition switch: OFF]
● Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
● Brake pedal: Slightly depressed
BATTERY VOLTAGE
(11 - 14V)
108 BR/W ASCD brake switch
[Ignition switch: ON]
● Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
● Brake pedal: Fully released
BATTERY VOLTAGE
(11 - 14V)
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
SEC011D
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
EC-660
Revision: October 2005
ASCD BRAKE SWITCH
2005 QX56
2. CHECK OVERALL FUNCTION-II
With CONSULT-II
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-II
Check voltage between ECM terminal 101 and ground under the following conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 7.
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
SEC013D
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
ASCD BRAKE SWITCH
EC-661
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3. CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check voltage between ASCD brake switch terminal 1 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M4
● 10A fuse
● Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
5. CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 108 and ASCD brake switch terminal 2.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ASCD BRAKE SWITCH
Refer to EC-663, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace ASCD brake switch.
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
EC-662
Revision: October 2005
ASCD BRAKE SWITCH
2005 QX56
7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
● Harness connectors M31, E152
● Fuse block (J/B) connector M60
● 10A fuse
● Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
10. CHECK STOP LAMP SWITCH
Refer to EC-663, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace stop lamp switch.
BBIA0373E
Voltage: Battery voltage
PBIB2102E
Continuity should exist.
ASCD BRAKE SWITCH
EC-663
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Revision: October 2005 2005 QX56
11. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
Component Inspection UBS00HDS
ASCD BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check harness continuity between ASCD brake switch terminals
1 and 2 under the following conditions.
If NG, adjust ASCD brake switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
STOP LAMP SWITCH
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check harness continuity between stop lamp switch terminals 3
and 4 under the following conditions.
If NG, adjust stop lamp switch installation, refer to BR-6,
"BRAKE PEDAL" , and perform step 3 again.
Condition Continuity
Brake pedal: Fully released Should exist.
Brake pedal: Slightly depressed Should not exist.
PBIB1536E
Condition Continuity
Brake pedal: Fully released Should not exist.
Brake pedal: Slightly depressed Should exist.
PBIB2103E
EC-664
Revision: October 2005
ASCD INDICATOR
2005 QX56
ASCD INDICATOR PFP:24814
Component Description UBS00HDT
ASCD indicator lamp illuminates to indicate ASCD operation status. Lamp has two indicators, CRUISE and
SET, and is integrated in combination meter.
CRUISE indicator illuminates when MAIN switch on ASCD steering switch is turned ON to indicate that ASCD
system is ready for operation.
SET indicator illuminates when following conditions are met.
● CRUISE indicator is illuminated.
● SET/COAST switch on ASCD steering switch is turned ON while vehicle speed is within the range of
ASCD setting.
SET indicator remains lit during ASCD control.
Refer to EC-29, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD)" for the ASCD function.
CONSULT-II Reference Value in Data Monitor Mode UBS00HDU
Specification data are reference value.
MONITOR ITEM CONDITION SPECIFICATION
CRUISE LAMP
● Ignition switch: ON
● MAIN switch: Pressed at the 1st
time → at the 2nd time
ON → OFF
SET LAMP
● MAIN switch: ON
● When vehicle speed is
between 40 km/h (25 MPH)
and 144 km/h (89 MPH)
● ASCD: Operating ON
● ASCD: Not operating OFF
ASCD INDICATOR
EC-665
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Revision: October 2005 2005 QX56
Wiring Diagram UBS00HDV
BBWA1717E
EC-666
Revision: October 2005
ASCD INDICATOR
2005 QX56
Diagnostic Procedure UBS00HDW
1. CHECK OVERALL FUNCTION
Check ASCD indicator under the following conditions.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2. CHECK DTC
Check that DTC U1000 or U1001 is not displayed.
OK or NG
OK >> GO TO 3.
NG >> Perform trouble diagnosis for DTC U1000, U1001. Refer to EC-163, "
DTC U1000, U1001 CAN
COMMUNICATION LINE" .
3. CHECK COMBINATION METER FUNCTION
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 4.
NG >> Go to DI-5, "
COMBINATION METERS" .
4. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
ASCD INDICATOR CONDITION SPECIFICATION
CRUISE LAMP
● Ignition switch: ON
● MAIN switch: Pressed at the 1st
time → at the 2nd time
ON → OFF
SET LAMP
● MAIN switch: ON
● When vehicle speed is between
40 km/h (25 MPH) and 144 km/h
(89 MPH)
● ASCD: Operating ON
● ASCD: Not operating OFF
MIL AND DATA LINK CONNECTOR
EC-667
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Revision: October 2005 2005 QX56
MIL AND DATA LINK CONNECTOR PFP:24814
Wiring Diagram UBS00HDX
BBWA1718E
EC-668
Revision: October 2005
MIL AND DATA LINK CONNECTOR
2005 QX56
BBWA1719E
SERVICE DATA AND SPECIFICATIONS (SDS)
EC-669
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EC
Revision: October 2005 2005 QX56
SERVICE DATA AND SPECIFICATIONS (SDS) PFP:00030
Fuel Pressure UBS00HE9
Idle Speed and Ignition Timing UBS00HEA
*: Under the following conditions:
● Air conditioner switch: OFF
● Electric load: OFF (Lights and heater fan)
● Steering wheel: Kept in straight-ahead position
Calculated Load Value UBS00HEB
Mass Air Flow Sensor UBS00HEC
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature Sensor UBS00HED
Engine Coolant Temperature Sensor UBS00HEE
A/F Sensor 1 Heater UBS00HEF
Heated Oxygen sensor 2 Heater UBS00HEG
Crankshaft Position Sensor (POS) UBS00HEH
Refer to EC-290, "Component Inspection" .
Camshaft Position Sensor (PHASE) UBS00HEI
Refer to EC-297, "Component Inspection" .
Throttle Control Motor UBS00HEJ
Fuel pressure at idling kPa (kg/cm
2
, psi)
Approximately 350 (3.57, 51)
Target idle speed
No-load*
(in P or N position)
650±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15° ± 5° BTDC
Condition Calculated load value % (Using CONSULT-II or GST)
At idle 14.0 - 33.0
At 2,500 rpm 12.0 - 25.0
Supply voltage Battery voltage (11 - 14V)
Output voltage at idle 1.0 - 1.3V*
Mass air flow (Using CONSULT-II or GST)
3.0 - 9.0 g·m/sec at idle*
9.0 - 28.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77) 1.94 - 2.06
80 (176) 0.295 - 0.349
Temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Resistance [at 25°C (77°F)] 2.3 - 4.3Ω
Resistance [at 25°C (77°F)] 5.0 - 7.0Ω
Resistance [at 25°C (77°F)] Approximately 1 - 15Ω
EC-670
Revision: October 2005
SERVICE DATA AND SPECIFICATIONS (SDS)
2005 QX56
Injector UBS00HEK
Fuel Pump UBS00HEL
Resistance [at 10 - 60°C (50 - 140°F)] 11.1 - 14.5Ω
Resistance [at 25°C (77°F)] 0.2 - 5.0Ω
