Applicable Systems
OBD-II
Symptoms
The idle air control system is not maintaining the correct idle speed. Engine idle may be too high or too low.
Possible Causes
- Idle air control valve stuck or failed
- Vacuum leak affecting idle airflow
- IAC control circuit wiring faulty
Troubleshooting Steps
- Step 1: Test idle air control valve operation
Valve responds to commands - Step 2: Inspect for vacuum leaks at intake manifold
No vacuum leaks found - Step 3: Check IAC control circuit wiring and connector
Wiring and connector intact
How to Reset
To reset: Clear the DTC after restoring proper idle speed control.
Source: SAE J2012 OBD-II Diagnostic Trouble Codes, SAE International
Category: OBD-II