Idle Speed/Throttle Actuator - Electronic: Description and Operation

Idle Air Control
Idle Air Control Valve (IAC Valve)
When the engine is cold, the A/C compressor is on, the transmission is in gear, the brake pedal is depressed, the P/S load is high, or the alternator Is charging, the ECM/PCM controls current to the IAC Valve to maintain the correct idle speed.