Oxygen Sensor Heating, Checking

Oxygen Sensor Heating, Checking

Only vehicles with engine code BEW

NOTE:
- Vehicle must be raised before connector for oxygen sensor is accessible.
- When servicing terminals in harness connector of oxygen sensor, use only gold-plated terminals.

Recommended special tools and equipment
- V.A.G1526 multimeter or V.A.G1715 multimeter
- V.A.G1594 connector test kit
- Wiring diagram

Test requirements







- The respective fuses of Diesel-Direct fuel injection system must be OK
- Ignition switched off.
- Disconnect 6-pin harness connector to Heated Oxygen Sensor (HO2S) -G39-. Harness connector of oxygen sensor is located at vehicle floor under a synthetic cover.







- Check resistance for sensor heater at connector to oxygen sensor terminal 3 + 4.

Specified value: 2.5 to 4.4 Ohms (at room temperature)

If specified value is not obtained:
- Replace Heated Oxygen Sensor (HO2S) -G39-.
- Erase DTC memory of control module for Diesel-Direct fuel injection system, 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.
- Connect adapter cable (V.A.G 1598/39-2) to test box (V.A.G 1598/42).







- Check wires between test box and 6-pin connector (to control module for Diesel-Direct fuel injection system) for open circuit according to wiring diagram.

Terminal 3 + socket 51

Wire resistance: max. 1.5 Ohms

- Check wires for short circuit to B+ or Ground (GND).

Specified value: Infinite Ohms

If no malfunctions are found in wires:
- Replace Diesel Direct Fuel Injection (DFI) Engine Control Module (ECM) -J248-.
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes