Idle Control System: Notes

NOTE: Fast idle is actuated by fast idle cam. For fast idle cam adjustment procedure, see IDLE SPEED & MIXTURE in ADJUSTMENTS article.

Idle speed is controlled by PCM through IAC valve. PCM controls idle speed components based upon signals received from various input devices. If idle speed components test correctly but idle speed is not being regulated properly, check the following input signals to PCM.

A/C Operation
Closed Throttle Position Switch
Crankshaft Position Sensor
Engine Coolant Temperature
Ignition (Start) Signal
Mass Airflow Sensor
Park/Neutral Switch
Power Steering Pressure Switch
Throttle Position Sensor
Vehicle Speed Sensor