DTC P0172: Notes
DTC P0172 DETECTION CONDITION AND POSSIBLE CAUSES
| DTC P0172 |
Fuel trim system too rich |
| DETECTION CONDITION |
- PCM monitors short fuel trim (SHRTFT) and long fuel trim (LONGFT) values when closed loop fuel control. If the LONGFT and the sum total of these fuel trims exceed preprogrammed criteria, PCM determines that the fuel system is too rich.
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.
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| POSSIBLE CAUSE |
- Misfire
- Front HO2S deterioration
- Front HO2S heater malfunction
- MAF sensor malfunction
- EGR valve improper operation
- Variable tumble solenoid valve improper operation
- Purge solenoid valve improper operation
- Pressure regulator malfunction
- Fuel pump malfunction
- Fuel return hose clogged
- Purge solenoid valve malfunction
- Purge solenoid hoses improper connection
- PCV valve malfunction
- PCM malfunction
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