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 PCM detects above malfunction condition in two consecutive drive cycles or in one drive cycle while DTC for the same malfunction has been stored in PCM.
- PENDING CODE is available if PCM detects the above malfunction condition during first drive cycle.
- FREEZE FRAME DATA is available.
- DTC is stored in the PCM memory.
|
| 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
|