Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Inspect for the following conditions:
- A high resistance in an IAC circuit.
- A restricted air intake system.
- Proper operation and installation of all air intake components.
- Any collapsed, clogged, or loose air intake ducts.
- A clogged air filter.
- Proper operation 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.
- Any objects blocking the IAC passage or throttle bore.
- Any excessive deposits in the IAC passage or on the IAC pintle.
- Any excessive deposits in the throttle bore or on the throttle plate.
- Any 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 determined to be intermittent, refer to INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.