Oxygen Sensor Heater For Oxygen Sensor Behind Three Way Catalytic Converter (TWC), Checking
NOTE:
- Vehicle must be raised before connector for oxygen sensor is accessible.
- When servicing terminals 3 and 4 in harness connector of Heated Oxygen Sensor (HO2S), use only gold-plated terminals.
Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 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.
Test sequence
- Unscrew protective cover (arrows) and disconnect 4-pin harness connector (black) -1- to Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-.
- Check resistance for sensor heater at connector to oxygen sensor terminal 1 + 2.
Specified value: 6,4...47,5 Ohm (at room temperature)
If specified value is not obtained:
- Replace Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-:
- Vehicles with engine code AFP, item 9.
- Vehicles with engine code BDF, item 13.
- 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 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.
Terminal 2 + socket 63
Wire resistance: max: 1.5 Ohm
- Also check wires for short circuit to B+ and Ground (GND).
Specified value: infinite Ohm
- 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 Ohm
If no malfunctions are found in wires:
- Replace Motronic Engine Control Module (ECM) -J220-.