Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Montana, 2002 Oldsmobile Silhouette, and 2002 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
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 loose air intake ducts.
- A clogged air filter.
- Proper operation of the Mass Air Flow (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 IAC passage or on the IAC pintle.
- 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 determined to be intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.