P0172

Tests 1 - 4:

Tests 5 - 7:

Tests 8 - 11:

Tests 12 - 16:

Tests 17 - 19:

SYMPTOM
P0172 - 1/1 FUEL SYSTEM RICH

WHEN MONITORED
With the engine running in closed loop mode, the ambient/battery temperature above 20 °F and altitude below 8000 ft.

SET CONDITION
If the PCM multiplies short term compensation by long term adaptive and the result is below a certain value for two trips, a freeze frame is stored, the MIL illuminates and a trouble code is stored.

POSSIBLE CAUSES
- Engine mechanical problem
- Fuel filter/pressure regulator (high)
- Fuel pump capacity (volume) out of specs
- High resistance in the fuel pump relay output circuit
- Fuel pump inlet strainer plugged
- TPS voltage change not smooth
- TPS voltage greater than 0.92 volts with throttle closed
- High resistance in the fuel pump ground circuit
- Fuel pump module
- Kinked/restricted fuel supply line
- ECT sensor (out of calibration)
- MAP sensor (out of calibration)