Diagnostic Aids
Inspect for the following conditions:
- High resistance in an IAC valve control circuit.
- Correct Positive Crankcase Ventilation (PCV) valve, properly installed and proper operation of PCV valve (if equipped).
- Proper operation and installation of all air intake components.
- Proper installation and operation of the Mass Air Flow (MAF) sensor, if equipped.
- Tampered with or damaged throttle stop screw.
- A misadjusted throttle cable.
- A skewed high Throttle Position (TP) sensor.
- 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 high or unstable idle condition could be caused by a non-IAC system condition that can not be overcome by the IAC valve.
- If the condition is determined to be intermittent, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L SATURN "L" SERIES article.