Common Symptoms
- Engine idle speed lower than normal
- Engine stalls when coming to a stop
- Rough or unstable idle
- Check Engine Light illuminated
- Engine dies after cold start
- Difficulty keeping engine running at idle
Most Likely Root Causes
- Dirty or carbon-fouled throttle body
- Vacuum leak at intake manifold or hoses
- Faulty idle air control valve or actuator
- Intake air leak after MAF sensor
- Faulty throttle position sensor
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Component Location
Idle air control valve is typically mounted on or near the throttle body assembly on the intake manifold.
Manufacturer Notes
Some manufacturers use electronic throttle control systems without traditional idle air control valves requiring different diagnostic approaches.
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