Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Sonoma and 2003 Chevrolet S10 Pickup. However, it is still accessible from the selected car via links, so may be relevant.
- High resistance in IAC valve control circuit.
- The correct PCV valve, properly installed and proper operation of PCV valve.
- Proper operation and installation of all air intake components.
- Proper installation and operation of the MAF sensor, 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 TP sensor.
- Excessive deposits in IAC passage or on IAC pintle.
- Excessive deposits in the 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.