Oxygen Sensor Heater For Oxygen Sensors Behind Three Way Catalytic Converter (TWC), Checking

Oxygen Sensor Heater For Oxygen Sensors Behind Three Way Catalytic Converter (TWC), Checking

NOTE: When servicing terminals in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.

Recommended special tools and equipment
- V.A.G 1526 portable multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Test requirements







- The respective fuses of Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- must be OK:
- Ignition switched off.

Vehicles with engine code AEB







- Disconnect 4-pin harness connector to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- (-1-).







- Use adapter cables from VAG1594 to connect multimeter to terminals 1 + 2 of connector to oxygen sensor for resistance measurement.
- Measure resistance value.
Specified value: 0.0 to 19.9 ohms

Vehicles with engine code ATW, AUG, AWM







- Disconnect 4-pin harness connector to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- (-1-).







- Set multimeter for resistance measurement and connect it to terminals 1 + 2 at connector for oxygen sensor. Check oxygen sensor heater for continuity.

Specified value: 0 to 20 ohms

Continued 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-, item 6

If oxygen sensor heater has continuity:
- Check voltage supply and wiring

Checking voltage supply and wiring







- Set multimeter for voltage measurement and connect it to terminals 1 + 2 at connector to control module.
- Start engine, and let run at idle.
- Measure voltage supply
Specified value: oscillating between 0.0 and 12.0 V

If there is no voltage:
- Connect multimeter to terminal 1 of connector and engine Ground (GND) for voltage measurement.
Specified value: 11 to 15 V

If there is no voltage again:
- Check wire connection from terminal 1 to Fuel Pump (FP) Relay -J17- according to wiring diagram.

If voltage was approximately same as battery voltage:
- Switch ignition off.
- Connect test box to control module wiring harness, connect test box for wiring test. Engine Control Module (ECM) is not connected. Test Box, Connecting For Wiring Test

Vehicles with engine code AEB







- Check wire between test box and 4-pin connector for open circuit according to wiring diagram.
Terminal 2+socket 28
Wire resistance: max: 1.5 ohms

Vehicles with engine code ATW, AUG, AWM







- Check wire between test box and 4-pin connector for open circuit according to wiring diagram.
Terminal 2 + socket 63
Wire resistance: max: 1.5 ohms

Continued for all vehicles

If no malfunctions are found in wires:
- Replace Engine Control Module (ECM)