The Idle Air Control (IAC) Valve is an engine component that regulates the amount of air entering the engine when the accelerator pedal is not being pressed.
Main functions
Controls engine idle speed.
Helps maintain a stable engine RPM when the vehicle is stationary.
Adjusts airflow when the air conditioner is switched on.
Helps prevent the engine from stalling at idle.
Supports smooth engine operation during cold starts.
Common signs of a faulty IAC valve
Irregular or fluctuating engine idle.
Engine idling too high or too low.
Engine stalling when stopping.
Rough idling when the AC is switched on.
Difficulty maintaining a steady idle