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.
Inspect for the following conditions:
- High resistance in an IAC circuit.
- Restricted air intake system.
- Proper operation and installation of all air intake components.
- Collapsed, clogged, or loose air intake ducts.
- A clogged air filter.
- Proper operation of the MAF sensor, if equipped.
- A tampered with or damaged throttle stop screw.
- A tampered with or damaged throttle plate, throttle shaft, or throttle linkage.
- Objects blocking the IAC passage or throttle bore.
- Excessive deposits in IAC passage or on IAC pintle.
- Excessive deposits in throttle bore or on throttle plate.
- Vacuum leaks.
- A low or unstable idle condition could be caused by a non-IAC system problem that cannot be overcome by the IAC valve.
If problem is determined to be intermittent, refer to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L SONOMA & S10 PICKUP article.