Diagnostic Aids
WARNING: This page is about a different car, the 2002 GMC Sonoma and 2002 Chevrolet S10 Pickup. 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.
- The correct PCV valve, properly installed and proper operation of the PCV valve.
- Proper operation and installation of all air intake components.
- Proper installation and operation of MAF, if equipped.
- A tampered with or damaged throttle stop screw.
- A tampered with or damaged throttle plate, throttle shaft, throttle linkage, or cruise control linkage, if equipped.
- A skewed high Throttle Position (TP) sensor.
- Excessive deposits in IAC passage or on IAC pintle.
- Excessive deposits in throttle bore or on throttle plate.
- Vacuum leaks.
- A high 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.