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. Refer to --> «General Diagnosis»(ref-276276-S40851803372008010300000) .
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°C)
If the specification was not obtained
- Replace the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000)
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. Refer to --> «24 MULTIPORT FUEL INJECTION (MFI)»(ref-276275-S13244009452008010300000) .
If the manufacturers test box is not being used. Perform the following step.
- Remove the Motronic Engine Control Module (ECM) J220. Refer to --> «Motronic Engine Control Module (ECM) J220, Replacing»(ref-276276-S39982482672008010300000) .
- 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 Three Way Catalytic Converter (TWC) G131 electrical harness connector terminal | Motronic Engine Control Module (ECM) J220 electrical connector terminal or test box 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. Refer to --> «Diagnostic Mode 04: Reset/Delete Diagnostic Data»(ref-276276-S31279847122008010300000)
- Perform a road test to verify repair.
If the DTC does not return
Repair complete, Generate readiness code. Refer to --> 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. Refer to --> «Motronic Engine Control Module (ECM) J220, Replacing»(ref-276276-S39982482672008010300000) .
- 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
- Check the DTC memory.
- If necessary, erase the DTC memory. Refer to «Diagnostic Mode 04: Reset/Delete Diagnostic Data»(ref-276276-S31279847122008010300000) .
- If the DTC memory was erased, generate readiness code. Refer to «Readiness Code»(ref-276276-S05799074302008010300000) .
End of diagnosis