DTC P0172:00: Notes
DTC P0172:00 (LF, L5) DETECTION CONDITION AND POSSIBLE CAUSE
| DTC P0172:00 |
Fuel trim system too rich |
| DETECTION CONDITION |
- The 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, the PCM determines that the fuel system is too rich.
Diagnostic support note
- This is a continuous monitor (fuel system).
- The 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 (Mode 2)/Snapshot data is available.
- The DTC is stored in the PCM memory.
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| POSSIBLE CAUSE |
- Misfire
- Erratic signal to PCM
- APP sensor signal malfunction
- ECT sensor signal malfunction
- MAF sensor signal malfunction
- TP sensor signal malfunction
- VSS signal malfunction
- A/F sensor heater malfunction
- A/F sensor malfunction
- Looseness A/F sensor
- A/F sensor deterioration
- MAF sensor malfunction
- Fuel supply system malfunction or improper fuel line pressure
- Pressure regulator malfunction
- Fuel pump unit malfunction
- Fuel leakage on fuel line from fuel delivery pipe and fuel pump
- Fuel filter clogged or restricted
- Fuel return hose clogged
- Improper connection of purge control system
- Improper operation of EGR valve system
- Improper operation of variable tumble solenoid valve
- Improper operation of PCV valve PCM malfunction
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