Oxygen Sensor Signal Wiring and Actuation, Checking

Oxygen sensor signal wire and activation, checking

NOTE: The oxygen sensor signal is monitored by the On Board Diagnostic (OBD) system.

- Check DTC memory.
- If malfunction related to oxygen sensor is displayed and oxygen sensor heater is OK, disconnect harness connector for relevant oxygen sensor.

Component location of 4-pin harness connector of oxygen sensor.

- Test voltage by connecting VAG1526 multimeter (measuring range 2 V) between sockets 3 and 4 of harness connector.







- Switch ignition on. Specification: 450 ± 50 mV.

If specification is not obtained: Check oxygen sensor wiring:
- Bank 1, Sensor 1.
- Bank 1, Sensor 2.
- Bank 2, Sensor 1.
- Bank 2, Sensor 2.

If specification is obtained:

- Replace relevant oxygen sensor.

Checking oxygen sensor wiring for Heated Oxygen Sensor (HO2S) -G39.

Component location of 4-pin harness connector of oxygen sensor.

- Disconnect 4-pin connector (black) for Heated Oxygen Sensor (HO2S) -G39.
- Connect VAG1598/31 test box to wiring harness for engine control module. DO NOT connect to engine control module itself. Connecting VAG 1598/31 Test Box

- Check following wiring connections for open circuits:







Connector on wiring VAG 1598/31
harness, socket test box socket
3 51
4 70

Resistance in wiring: max. 1.5 Ohm

- Check wiring on 4-pin connector for short circuits to each other.







Connector on wiring VAG 1598/31
harness, socket test box socket
4 51

Specification: infinity ohm (open circuit)

- Check shield wire for short circuit to sensor wiring.

Connector on wiring VAG 1598/31
harness, socket test box socket
4 32
3 32

Specification: infinity ohm (open circuit)

If no malfunctions are identified in the wiring:
- Replace Motronic Engine Control Module (ECM) -J220.

Checking wiring for Oxygen Sensor (O2S) 2 after Three Way Catalytic Converter (TWC) -G131

Component location of 4-pin harness connector of oxygen sensor.

- Disconnect 4-pin connector for Oxygen Sensor (O2S) 2 after Three Way Catalytic Converter (TWC) -G131

- Connect VAG 1598/31 test box to wiring harness for engine control module. DO NOT connect to engine control module itself. Connecting VAG 1598/31 Test Box

- Check following wiring connections for open circuits:







Connector on wiring VAG 1598/31
harness, socket test box socket
3 10
4 11

Resistance in wiring: max. 1.5 ohm

- Check wires on 4-pin connector for short circuits to each other.







Connector on wiring VAG 1598/31
harness, socket test box socket
4 10

Specification: infinity ohm (open circuit)

- Check shielded wire for short circuit to sensor wiring.

Connector on wiring VAG 1598/31
harness, socket test box socket
4 32
3 32

Specification: infinity ohm (open circuit)

If no malfunctions are identified in the wiring:
- Replace Motronic Engine Control Module (ECM) -J2203.

If no malfunction can be identified in the wiring:
- Replace Motronic Engine Control Module (ECM) -J220.
- Display readiness code. Readiness Code Reading Readiness code must be regenerated if DTC memory was erased. Readiness Code, Generating