DTC Description
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 DETECTION LOGIC
| DTC | CONSULT screen terms (Trouble diagnosis content) | DTC detection condition | |
| P0171 | FUEL SYS-LEAN-B1 (System too lean bank 1) | Diagnosis condition | - |
| Signal (terminal) | - | ||
| Threshold |
|
||
| Diagnosis delay time | - | ||
POSSIBLE CAUSE
- Intake air leakage
- A/F sensor 1
- Fuel injector
- Exhaust gas leakage
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor
- Incorrect PCV hose connection
FAIL-SAFE
| Engine operating condition in fail-safe mode | ||
|---|---|---|
| Fail safe mode | Vehicle behavior | |
| Traveling control mode | Accelerator angle variation control | 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:
|
| Combustion control mode | Stratified charge combustion control at starting | No stratified charge combustion at starting (cold start). |
| Idle speed control | Stops feedback control of idle speed and controls with specified speed. | |
| Recovery speed control at decelerating | Stops recovery speed control by the fuel cut at decelerating and controls with specified speed. | |
| Idle neutral control | Stops idle neutral control. | |