P0171

Tests 1 - 4:

Tests 5 - 8:

Tests 9 - 12:

Tests 13 - 15:

Test 16:

SYMPTOM
P0171-1/1 FUEL SYSTEM LEAN

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

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
- Intermittent Condition
- Restricted Fuel Supply Line
- Fuel Pump Inlet Strainer Plugged
- Fuel Pump Module
- O(2) Sensor
- O(2) Sensor Signal Circuit Shorted To Ground
- O(2) Sensor Heater Operation
- Throttle Position Sensor Voltage Greater Than 0.92 Volts With Throttle Closed
- Throttle Position Sensor Sweep
- MAP Sensor Operation
- ECT Sensor Operation
- Engine Mechanical Problem
- Fuel Filter/Pressure Regulator (High)
- PCM