DTC P2178 [L3]: Notes
DTC P2178 (L3) DETECTION CONDITION & POSSIBLE CAUSES
| DTC P2178 |
Fuel system too rich at off idle |
| DETECTION CONDITION |
- PCM monitors short term fuel trim (SHRTFT) and long term fuel trim (LONGFT) during closed loop fuel control at off-idle. If the LONGFT and the sum total of these fuel trims or SHRTFT exceed pre programmed criteria. PCM determines that fuel system is too rich at off-idle.
Diagnostic support note
- This is a continuous monitor. (Fuel system)
- MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
- PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
- FREEZE FRAME DATA is available.
- DTC is stored in the PCM memory.
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| POSSIBLE CAUSE |
- Erratic signal to PCM
- ECT sensor
- MAF sensor
- TP sensor
- Related connector or terminal malfunction
- Related wiring harness malfunction
- Leakage exhaust system
- A/F sensor deterioration
- A/F sensor heater malfunction
- MAF sensor malfunction
- Air suction in intake air system
- Purge solenoid valve improper operation
- Purge solenoid valve malfunction (stuck open)
- Purge solenoid hoses improper connection
- EGR valve improper operation
- VTCS improper operation
- Variable valve timing control system improper operation
- Pressure regulator (built-in fuel injection pump) malfunction
- Fuel pump malfunction
- PCV valve malfunction
- Misfire
- PCM malfunction
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