Possible Causes
WARNING: This page is about a different car, the 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when idle speed continues to vary greatly from target speed. Possible causes are:
- Defective Positive Crankcase Ventilation (PCV) valve hose or connection.
- IAC valve is stuck or remains closed.
- IAC valve circuit is open or shorted.
- A/C signal circuit is open or shorted.
- Air induction system malfunction.
- Defective ECM.