Diagnostic Aids
Inspect for the following conditions:
- High resistance in an IAC valve control 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 the MAF sensor.
- 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 the throttle plate.
- Vacuum leaks.
- A high or unstable idle condition could be caused by a non-IAC system problem that cannot be overcome by the IAC valve.
- An intermittent condition.