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 oxygen sensor, use only gold-plated terminals.
Recommended special tools and equipment
- V.A.G 1526 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- and Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- must be OK:
- Ignition switched off.
Test sequence
- Disconnect 4-pin harness connector to the respective oxygen sensor:
Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- 4-pin harness connector (green, arrow).
Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131- 4-pin harness connector (brown, arrow).
NOTE:
- Bank 1 = Cylinder bank 1, in direction of travel, right
- Bank 2 = Cylinder bank 2, in direction of travel, left
Vehicles with engine code AHA
- Measure resistance for sensor heater at connector to oxygen sensor terminal 1 +2.
Specified value: 0.0 to 19.9 ohms
Vehicles with engine code ATQ
- Measure resistance for sensor heater at connector to oxygen sensor terminal 1+2. Specified value: max. 200 ohms
Continuation for all vehicles
If specified value is not obtained:
- Replace the respective oxygen sensor:
- Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-
- Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) -G131-.
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If specified value is obtained:
- Check Ground (GND) activation of the respective oxygen sensor heater.
- Connect test box to control module wiring harness. connect test box for wiring test. Test Box, Connecting For Wiring Test
- Check wires between test box and 4-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram.
Wire resistance: max. 1.5 ohms
Vehicles with engine code AHA
Vehicles with engine code ATQ
Continuation for all vehicles
- Also check wires for short circuit to B+ and to Ground (GND).
Specified value: Infinite ohms
- Check wire between 4-pin connector terminal 1 and Fuel Pump (FP) Relay -J17- for open circuit according to wiring diagram.
Wire resistance: max. 1.5 ohms
If no malfunctions are found in wires:
- Replace Motronic Engine Control Module (ECM) -J220-.