DTC Description
DTC DETECTION LOGIC
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 A/F sensor 1. 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 condition as the fuel injection system malfunction and illuminates the MIL (2 trip detection logic).
| 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. | CONSULT screen terms (Trouble diagnosis content) |
DTC detecting condition |
|---|---|---|
| P0171 | FUEL SYS-LEAN-B1 (System too lean bank 1) |
|
POSSIBLE CAUSE
- 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
FAIL-SAFE
| Fail safe mode | Vehicle behavior |
|---|---|
| Traveling control mode | ECM controls the accelerator pedal depression speed to make it slower than actual speed. This causes a drop in accelerating performance and encourages the driver to repair malfunction.
NOTE:
ECM does not control the accelerator pedal releasing speed.
|
| Combustion control mode |
|