Diagnostic Aids
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Inspect for the following conditions:
- High resistance in an IAC circuit.
- Restricted air intake system.
- Proper operation and installation of all air intake components.
- Collapsed, clogged, or loosed air intake ducts.
- A clogged air filter.
- Proper operating of the Mass Airflow (MAF) sensor, if equipped.
- A tampered with or damaged throttle stop screw.
- A tampered with or damaged throttle plate, throttle shaft, or throttle linkage.
- Objects blocking the IAC passage or throttle bore.
- Excessive deposits in the throttle bore or on the throttle plate.
- Vacuum leaks.
- A low or unstable idle condition could be caused by a non-IAC system problem that can not be overcome by the IAC valve.
If the problem is intermittent, See INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.