Idle Speed: Adjustments

RELEARN PROCEDURE
Whenever an Idle Air Control (IAC) component is replaced or cleaned or a service affecting idle is performed, it is recommended that Keep Alive RAM be cleared. This is necessary so the idle strategy does not use the previously learned Idle Air Trim values.

To clear Keep Alive RAM, refer to Computer and Control Systems / System Diagnosis / Powertrain Control Module (PCM) Reset (Clearing DTCs). It is important to note that erasing DTCs with a scan tool does not reset the Idle Air Trim table.

Idle Air Trim Learning Modes Chart:

Once Keep Alive RAM has been reset, the engine must idle for 15 minutes (actual time varies between strategies) to learn new idle air trim values. Idle quality will improve as the strategy adapts. Adaptation occurs in four separate modes shown in the table provided.