Like the idle speed actuator and automatic choke on a carburetor, the idle air controller (IAC) helps warm up the engine quickly with a fast idle and restricted air flow (for a richer mixture), then maintains a consistent idle speed when the engine's at operating temperature. A failed IAC can cause a rough idle and Check Engine light. If you've narrowed it down to the idle air control valve on your vehicle, shop Advance to find the part you're looking for!
Back in the days of carbureted engines, the automatic choke and fast-idle cam were responsible for restricting airflow into the carb and keeping idle speed up until the engine reached operating temperature. Today, that's taken care of by the idle air controller. A failed IAC can result in a high idle, lumpy idle or an idle speed that's too low. It can also lead to stalling as the engine can't take in enough air. In extreme cases, your vehicle won't start. Shop Advance to find the correct OEM-quality idle air controller for your ride.