System Lean, L-Idle Adap at Rich Limit

NAME OF CODE
System Lean. L-Idle Adap at Rich Limit

SET CONDITION
Engine running lean; Powertrain Control Module (PCM) trying to adapt fuel/air mixture rich.

THEORY OF OPERATION
This trouble code can be caused by several things not related to PCM electronics. Idle adaptive memory is designed to aid in fuel/air control. Its function is to adapt the fuel/air mixture to correct for fuel pressure differences and other mechanical changes such as engine wear and mechanical malfunctions.

The fuel control system goes to open loop mode when the oxygen sensor has indicated a continuous lean mixture of exhaust gas.

POSSIBLE CAUSES
- Ignition system
- Fuel pump/filter
- Injectors
- Fuel pressure
- Manifold Absolute Pressure (MAP) sensor
- O2 sensor
- Vacuum leak
- Mechanical engine problem
- Wiring harness/connectors