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Oxygen Sensor Heater For Oxygen Sensor In Center Catalytic Converter, Checking



Oxygen Sensor Heater For Oxygen Sensor In Center Catalytic Converter, Checking (vehicles With Engine Code BKF, BNU)

NOTE:
- Vehicle must be raised before oxygen sensor connector 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
- 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 Heated Oxygen Sensor (HO2S) -G465- must be OK.
- Fuel Pump (FP) Relay -J17- must be OK, check.
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.

Test sequence







- Remove protective cover (arrows) and disconnect 4-pin harness connector to Oxygen Sensor (O2S) in Center Three Way Catalytic Converter (TWC), Bank 1 -G465-

Checking resistance







- Check resistance for sensor heater at connector to oxygen sensor terminal 1 + 2.

Specified value: 1.0 to 20.0 Ohms (at room temperature)

If specified value is not obtained:
- Replace Oxygen Sensor (O2S) in Center Three Way Catalytic Converter (TWC), Bank 1 -G465-.
- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code.

If specified value is obtained:
- Check Ground (GND) activation of oxygen sensor heater.

Checking Ground (GND) activation of oxygen sensor heater
- Connect test box to control module wiring harness. connect test box 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 Ohms

- 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

- Erase DTC memory of Engine Control Module (ECM). Diagnostic mode 4: Reset/erase diagnostic data.
- Generate readiness code.

If no malfunctions are found in wires:
- Replace Motronic Engine Control Module (ECM) -J220-.