Diagnostic Aids
WARNING: This page is about a different car, the 2003 Pontiac Sunfire, 2003 Pontiac Grand Am, 2003 Oldsmobile Alero, and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
Check for the following conditions:
- High resistance in an IAC valve control circuit.
- The correct Positive Crankcase Ventilation (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 Mass Air Flow (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.
- Tampered with or damaged throttle stop screw.
- 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 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.
- High or unstable idle condition caused by a non-IAC system problem that can not be overcome by IAC valve.
- If the problem is determined to be intermittent, see INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L ALERO, CAVALIER, GRAND AM & SUNFIRE - GASOLINE article or INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L CAVALIER - BI-FUEL - CNG/GASOLINE article.