Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. 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 valve control circuit.
- Restricted air intake system.
- Proper operating and installation of all air intake components.
- Collapsed, clogged, or loose air intake ducts.
- A clogged air filter.
- Proper operating 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 in the throttle plat.
- Vacuum leaks.
- A low or unstable idle condition could be caused be a non-IAC valve.
- For an intermittent condition, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.