Loading ...
Loading ...
Loading ...
On Board Diagnosis Logic
NGEC0690
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 heated oxygen
sensors 1 (front). The ECM calculates 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 condi-
tion as the fuel injection system malfunction and light up the MIL
(2 trip detection logic).
Sensor Input Signal to ECM
ECM func-
tion
Actuator
Heated oxygen sensors 1 (front)
Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel injec-
tion control
Injectors
Malfunction is detected when fuel injection system does not oper-
ate properly, the amount of mixture ratio compensation is too large.
(The mixture ratio is too lean.)
POSSIBLE CAUSE
NGEC0690S01
쐌 Intake air leaks
쐌 Heated oxygen sensor 1 (front)
쐌 Injectors
쐌 Exhaust gas leaks
쐌 Incorrect fuel pressure
쐌 Lack of fuel
쐌 Mass air flow sensor
DTC P0171 (RIGHT, -B1), P0174 (LEFT, -B2) FUEL INJECTION
SYSTEM FUNCTION (LEAN)
VG33E
On Board Diagnosis Logic
EC-884
Loading ...
Loading ...
Loading ...