Idle Air Control Valve

An air passage by-passing throttle valve is provided to route intake air directly into intake manifold. ECM-energized IAC valve regulates airflow through this passage. IAC valve is located on side of throttle body.

Air is allowed to pass through IAC valve when it is energized. Solenoid portion of valve is energized whenever idle speed drops to less than desired RPM due to engine load (i.e., electrical, A/C, P/S, automatic transmission in Drive, etc.). IAC valve is also energized each time engine is started and during periods of deceleration (to compensate for rich mixtures caused by a fully closed throttle). Duration of IAC valve operation is dependent on coolant temperature.