Oxygen Sensor Heater after Catalytic Converter, Checking
Oxygen Sensor Heater After Catalytic Converter, Checking
Oxygen Sensor 1 Heater, Checking
NOTE:
- Oxygen Sensor (O2S) 1 (behind Three Way Catalytic Converter (TWC)) Heater Z29 is part of Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 and cannot be replaced separately.
- When servicing electrical harness connector terminals for the Heated Oxygen Sensor (H02S), use only gold-plated terminals.
Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.
Test requirements
- Fuse (on fuse panel) S243 OK.
- Fuel Pump (FP) Relay J17 OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Ignition switched off.
Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis
Start diagnosis
- Remove the retaining screws -1 and 2 - and the cover.
Checking internal resistance
- Disconnect the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 electrical harness connector -1 -.
- Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 terminals 1 to 2 for resistance.
Specified value: 1.0 to 20.0 Ohms (at approx. 20 degrees C)
If the specification was not obtained:
- Replace the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130.
If the specification was obtained:
Checking voltage supply
- Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 electrical harness connector terminal 1 to ground (GND) for voltage.
Specified value: Battery voltage.
If the specification was not obtained:
- Check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 electrical harness connector terminal 1 to the Fuel Pump (FP) Relay J17 socket 23/87 an open circuit, a short circuit to each other, Battery (+), or Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
If the specification was obtained:
Checking Ground (GND) activation
If the manufacturers test box is being used. Perform the following step.
- Install the test box VAG1598/31.
If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J220.
- Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 electrical harness connector to the Motronic Engine Control Module (ECM) J220 electrical harness connector for resistance.
Oxygen Sensor (O2S) Behind Motronic Engine Control Module (ECM)
Three Way Catalytic Converter J220 electrical connector
(TWC) G130 electrical harness terminal or test box
connector terminal socket
2 63
Specified value: 1.5 Ohms max.
If the specification was not obtained:
- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
If no malfunction is detected in the wiring and if the voltage supply was OK:
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.
If the DTC does not return:
Repair complete, Generate readiness code. Readiness Code
- End diagnosis.
If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Motronic Engine Control Module (ECM) J220.
- Assembly is performed in the reverse of the removal.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code.
End of diagnosis
Oxygen Sensor 2 Heater, Checking
NOTE:
- Oxygen Sensor (O2S) 2 (behind Three Way Catalytic Converter (TWC)) Heater Z30 is part of Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 and cannot be replaced separately.
- When servicing electrical harness connector terminals for the Heated Oxygen Sensor (HO2S), use only gold-plated terminals.
Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.
Test requirements
- Fuse (on fuse panel) S243 OK.
- Fuel Pump (FP) Relay J17 OK.
- Battery voltage at least 12.5 volts.
- All electrical consumers such as, lights and rear window defroster, switched off.
- Vehicles with automatic transmission, shift selector lever into position "P" or "N".
- A/C switched off.
- Ground (GND) connections between engine/transmission/chassis OK.
- Ignition switched off.
Test procedure
- Perform a preliminary check to verify the customers complaint. General Diagnosis
Start diagnosis
- Remove the retaining screws -1 and 2 - and the cover.
Checking internal resistance
- Disconnect the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 electrical harness connector - 2 -.
- Using a multimeter, check the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 terminals 1 to 2 for resistance.
Specified value: 1.0 to 20.0 Ohms (at approx. 20 degrees C)
If the specification was not obtained:
- Replace the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131.
If the specification was obtained:
Checking voltage supply
- Using a multimeter, check the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 electrical harness connector terminal 1 to ground (GND) for voltage.
Specified value: Battery voltage.
If the specification was not obtained:
- Check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) G130 electrical harness connector terminal 1 to the Fuel Pump (FP) Relay J17 socket 23/87 an open circuit, a short circuit to each other, Battery (+), or Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
If the specification was obtained:
Checking Ground (GND) activation
If the manufacturers test box is being used. Perform the following step.
- Install the test box VAG1598/31.
If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J220.
- Using a multimeter, check the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 electrical harness connector to the Motronic Engine Control Module (ECM) J220 electrical harness connector for resistance.
Oxygen Sensor (O2S) 2 Behind Motronic Engine Control Module (ECM)
Three Catalytic Converter (TWC) J220 electrical connector
G131 electrical harness terminal or test box
connector terminal socket
2 6
Specified value: 1.5 Ohms max.
If the specification was not obtained:
- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- If necessary, repair the faulty wiring connection.
If no malfunction is detected in the wiring and if the voltage supply was OK:
- Erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
- Perform a road test to verify repair.
If the DTC does not return:
Repair complete, Generate readiness code. Readiness Code
- End diagnosis.
If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:
- Replace the Motronic Engine Control Module (ECM) J220.
- Assembly is performed in the reverse of the removal.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code.
End of diagnosis