Idle Air Control (IAC) Valve: Notes
- Check idle speed following procedures in ADJUSTMENTS article. If idle speed is as specified, go to next step. If idle speed is not as specified, follow procedures in DTC P0505 in TESTS W/CODES article.
- With engine running, turn headlights on. If idle remains at specified idle speed, system is okay. If idle speed is not within specification, go to next step.
- Turn ignition off. Disconnect IAC valve hose from air intake pipe. Turn ignition on. Blow through end of hose and ensure air does not pass through valve. Turn ignition off. On models with 3-speed automatic or manual transmission, connect a fused jumper wire (backprobe) between PCM harness connector "B", terminal No. 12, (Light Green/Black wire) to ground. On models with 4-speed automatic transmission, connect a fused jumper wire (backprobe) between PCM harness connector "A", terminal No. 12, (Light Green/Black wire) to ground. Turn ignition on. Blow through end of hose and ensure air passes through valve. If operation is not as specified, go to next step. If operation is as specified, replace PCM. Retest system.
- Turn ignition off. Disconnect IAC valve harness connector. Using an ohmmeter, measure resistance between terminals of IAC valve. If resistance is 11-14 ohms at 68°F (20°C), go to next step. If resistance is not as specified, replace IAC valve. Retest system.
- Blow into disconnected IAC valve hose. Ensure air does not pass through. Using fused jumper wires, connect battery voltage and ground to IAC valve terminals. Air should now pass through valve. Replace IAC valve if operation is not as specified. If IAC valve is okay, check IAC valve harness for open or short. Repair as necessary.
ISC DUTY SPECIFICATION
| Engine Load | ISC Duty Increase Percentage |
|---|---|
| Electrical Load | About 3.5 |
| Radiator Fan | About 3.5 |
| A/C | About 10 |
NOTE:
DO NOT
remove ISC actuator from throttle body; it is adjusted by manufacturer.