Oxygen Sensor (O2S) Heating Element
- Disconnect O2S heating element connector. See the ELECTRICAL COMPONENT LOCATIONS table at beginning of article. Connect voltmeter between harness connector terminals. Start engine and let idle. If battery voltage is not present, check for faulty circuit breaker, wiring or fuel pump relay.
- If battery voltage is present, connect Test Cable (VAG 1315 A/1) to O2S heating element connector. Run engine at idle. Set ammeter on 10-amp scale. Check amperage at test cable terminals. If 0.5-3.0 amps is present, heating element is okay. If 0.5-3.0 amps is not present, replace O2S.
NOTE:
To check O2S control function, read individual measuring values in channels 2 and 3. See READING INDIVIDUAL MEASURING VALUES in G - TESTS W/ CODES article in the ENGINE PERFORMANCE Section.