Oxygen Sensor Heater after Catalytic Converter, Checking

Oxygen Sensor Heater After Catalytic Converter, Checking

NOTE: When servicing terminals in harness connector of Heated Oxygen Sensor (H02S), use only gold-plated terminals.

Recommended Special Tools, Workshop Equipment, Testers, Measuring Instruments and Auxiliary Items
- V.A.G 1526 portable multimeter or V.A.G 1715 multimeter
- Adapter set V.A.G 1594
- Wiring diagram

Test Conditions
- Corresponding Oxygen Sensor O2S Behind Three Way Catalytic Converter (TWC) -G130- must be OK
- Ignition switched off.

Engine Codes AMU, ATC







- Disconnect 4-pin connector to Oxygen Sensor O2S Behind Three Way Catalytic Converter (TWC) -G130-.
- Set multimeter to resistance measurement and connect to terminals 1 +2 on oxygen sensor connector. Check sensor heating for continuity.







Specified value: 1 to 5 Ohms ~(at room temperature)

Engine Codes AWP, BEA
- Disconnect 4-pin connector to Oxygen Sensor O2S Behind Three Way Catalytic Converter (TWC) -G130-.
- Set multimeter to resistance measurement and connect to terminals 1 +2 on oxygen sensor connector. Check sensor heating for continuity.







Specified value: 6.4 to 47.5 Ohms ~(at room temperature)

Continuation for All Vehicles

If an open circuit is found in the oxygen sensor heater:
- Replace Oxygen Sensor O2S Behind Three Way Catalytic Converter (TWC) -G130-.

If sensor heating has continuity:
- Check voltage supply and wiring.

Voltage Supply and Wiring, Checking







- Set multimeter to voltage measurement and connect to terminals 1 + 2 at connector to ECM.
- Start engine and run at idle speed.
- Measure voltage supply

Specified value: fluctuation between 0.0 to 12.0 V

If there is no voltage:
- Connect multimeter to terminal 1 of connector and engine Ground (GND) for voltage measurement.
- Briefly operate starter.

Specified value: approx. battery voltage

If there is still no voltage:
- Check wiring harness from terminal 1 to Fuel Pump (FP) Relay -J17- according to wiring diagram

If voltage was approx. battery voltage:
- Switch off ignition.
- Connect test box to ECM wiring harness. Test Box, Connecting For Wiring Test

The Engine Control Module (ECM) remains disconnected.
- Check wiring between test box and 4-pin connector for open circuit according to wiring diagram.
Terminal 2 + Socket 63







Wiring resistance: max. 1.5 Ohms

If no fault is detected in the wiring:
- Replace Engine Control Module (ECM).