Loading ...
Loading ...
Loading ...
SEF327R
Component Description
NFEC0896
The heated oxygen sensor 2, after three way catalyst, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen 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
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 is not used
for engine control operation.
CONSULT-II Reference Value in Data Monitor
Mode
NFEC0897
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)
I Engine: After warming up
Revving engine from idle up to
2,000 rpm
0 - 0.3V +, Approx. 0.6 - 1.0V
HO2S2 MNTR
(B1)
HO2S2 MNTR
(B2)
LEAN +, RICH
SEF305UA
On Board Diagnosis Logic
NFEC0899
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxy-
gen storage capacity before the three way catalyst 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.
DTC No.
Trouble diagnosis
name
DTC Detecting Condition Possible Cause
P0138
0138
(Bank 1)
P0158
0158
(Bank 2)
Heated oxygen sen-
sor 2 circuit high volt-
age
An excessively high voltage from the sensor is
sent to ECM.
I Harness or connectors
(The sensor circuit is open or
shorted.)
I Heated oxygen sensor 2
GI
MA
EM
LC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0138, P0158 HO2S2
Component Description
EC-249
Loading ...
Loading ...
Loading ...