Circuit Description

ECM operates IAC valve to perform idle-up and provide feedback for target idling speed. DTC is set when idle speed continues to vary greatly from target speed. Possible causes are:

• Idle Air Control (IAC) valve stuck, or closed.
• IAC valve circuit is open or shorted.
• A/C switch circuit is open or shorted.
• Air induction system malfunction.
• Defective ECM.