EuroVan (2.5L)
- Check Idle Air Control (IAC) valve using OUTPUT DIAGNOSTIC TEST MODE. See the TESTS W/CODES article. Turn ignition on. IAC valve must vibrate or hum. If IAC valve does not vibrate or hum, turn ignition off and disconnect IAC valve.
- Connect Digital Volt-Ohmmeter (DVOM) to IAC valve using test leads from Adapter Kit (VW 1594). IAC valve resistance should be 2-10 ohms. If resistance is incorrect, replace IAC valve.NOTE: IAC valve control current amperage may vary between 400-1000 milliamps depending on engine load (A/C on, power steering at full lock, incorrect ignition timing).
- If IAC valve is working properly, ensure engine coolant temperature is at least 176°F (80°C). Ensure idle speed is correctly set and no air leaks exist in air intake system.
- With IAC valve disconnected, install Test Harness (VAG 1315A/2) between IAC valve and wiring harness connector. See Fig 1 . Using test leads from adapter kit, connect DVOM to test harness.
- Start engine and allow it to idle. With engine at 775-825 RPM, IAC valve control current must be 500-600 milliamps. With throttle closed, disconnect Blue Engine Coolant Temperature (ECT) sensor.
- With ECT sensor disconnected, IAC valve control current must remain at 500-600 milliamps. If IAC valve control current is not as specified, repair circuit or replace ECM as necessary.
NOTE:
If engine stalls, reconnect ECT before re-starting engine. This will prevent ECM from entering "limp home" mode, making IAC control current measurements inaccurate.