Common Symptoms
- Engine idle speed is excessively high
- Idle speed does not decrease when engine warms up
- Check Engine Light illuminated
- Engine may stall when decelerating to a stop
- Rough or unstable idle quality
- Increased fuel consumption at idle
Most Likely Root Causes
- Faulty idle air control valve or motor
- Carbon buildup in throttle body restricting airflow control
- Wiring harness short to voltage in idle control circuit
- Vacuum leak downstream of throttle body
- Failed powertrain control module
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Component Location
The 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 that replace traditional idle air control valves with throttle motor control.
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