DTC P2178: Notes
DTC P2178 DETECTION CONDITION AND POSSIBLE CAUSES
| DTC P2178 |
Fuel system too rich at off idle |
| DETECTION CONDITION |
- PCM monitors short term fuel trim (SHRTFT), long term fuel trim (LONGFT) during closed loop fuel control at off-idle. If the LONGFT and the sum total of these fuel trims exceed preprogrammed 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 |
- Misfire
- Front HO2S deterioration
- Front HO2S heater malfunction
- MAF sensor malfunction
- Pressure regulator (built-in fuel injection pump) malfunction
- Fuel pump malfunction
- EGR valve improper operation
- VTCS improper operation
- Purge solenoid valve improper operation
- Purge solenoid valve malfunction (stuck open)
- Purge solenoid hoses improper connection
- PCV valve malfunction
- Variable valve timing control system improper operation
- PCM malfunction
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