1. After starting the engine, the IAC valve opens for a while. The air consumption increases, increasing the speed x.x. approximately 150-300 rpm (min').
2. When the coolant temperature is low, the IAC valve opens and the desired fast idle speed is reached. Thus, the flow rate of bypassed air is adjusted depending on the temperature of the engine coolant.
3. When the speed x.x. different from normal, but the malfunction indicator lamp (MIL) does not generate a diagnostic trouble code (DTC) 14, check the following items:
- Signal from the air conditioner
- Signal from ALT FR
- Stoplight switch signal
- starter signal
- PSP switch signal
- Signal from the automatic transmission selector switch
- Hoses and fittings
- IAC valve and its O-rings
4. If the items listed are OK but the MIL does not generate DTC14 after replacing the IAC valve, substitute a known-good ECM/PCM and recheck. If symptom goes away, replace original ECM/PCM.
1. black and yellow; 2. from the PGM-FI main relay; 3. various sensors; 4. ECM/PCM module; 5. blue-black; 6. orange; 7. black; 8. intake manifold; 9. engine coolant; 10. iac valve