P0174

Test 1 - 4:

Test 5 - 8:

Test 9 - 11:

Test 12 - 14:

SYMPTOM
P0174-FUEL SYSTEM 2/1 LEAN

TEST NOTE
This symptom is diagnosed using the test P0171-FUEL SYSTEM 1/1 LEAN.

WHEN MONITORED
With the engine running in closed loop mode, the ambient/battery temperature above (-7° C) 20° F, altitude below 8500 ft and fuel level greater than 15%.

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

POSSIBLE CAUSES
- Good trip equal to zero
- Restricted fuel supply line
- Fuel pump inlet strainer plugged
- Fuel pump module
- O2 sensor
- O2 signal circuit
- O2 return circuit
- O2 sensor heater operation
- Throttle position sensor sweep
- MAP sensor operation
- ECT sensor operation
- Engine mechanical problem
- Fuel contamination/exhaust leak