Heated Oxygen Sensor Before Catalytic Converter, Checking
Heated Oxygen Sensor before Catalytic Converter, Checking
Heated Oxygen Sensor 1, Checking
• Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Heated Oxygen Sensor (HO2S) ( G39).
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Test requirements
• Fuse (S243) OK.
• Motronic Engine Control Module (ECM) (J220) fuses 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 => [ Preliminary Check ] Preliminary Check.
Start diagnosis
- Perform the function test in Diagnostic Mode 06. Refer to => [ Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions ] Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions.
If specified values are obtained:
- End diagnosis and switch the ignition off.
If the specified values are not obtained:
Checking primary voltage
- Disconnect the Heated Oxygen Sensor (HO2S) (G39 ) electrical harness connector - 2 -.
- Using a multimeter, check the Heated Oxygen Sensor (HO2S) (G39) electrical harness connector terminals 1 to 5 for voltage.
Specified value: 0.400 to 0.500 V
- Switch the ignition off.
If the specified value was not obtained:
- Replace the Heated Oxygen Sensor (HO2S) (G39). Refer to Fuel Injection and Ignition Repair Information
If the specified value was obtained:
Checking wiring
If the manufacturers test box is being used, perform the following step.
- Install the test box (VAG1598/31). Refer to Fuel Injection and Ignition Repair Information
If the manufacturers test box is not being used, perform the following step.
- Remove the Motronic Engine Control Module (ECM) ( J220). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.
- Using a Multimeter, check the Heated Oxygen Sensor (HO2S) (G39) electrical harness connector terminals to the Motronic Engine Control Module (ECM) ( J220) electrical harness connector terminals for resistance.
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 found in the wiring:
- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase 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. Refer to => [ 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). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.
- 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. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.
End of diagnosis
Heated Oxygen Sensor 2, Checking
• Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Heated Oxygen Sensor (HO2S) 2 ( G108).
Special tools, testers and auxiliary items required
• Multimeter.
• Wiring diagram.
Test requirements
• Fuse (S243) OK.
• Motronic Engine Control Module (ECM) (J220) fuses 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 => [ Preliminary Check ] Preliminary Check.
Start diagnosis
- Perform the function test in Diagnostic Mode 06. Refer to => [ Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions ] Diagnostic Mode 06 - Read Test Results for Specific Diagnostic Functions.
If specified values are obtained:
- End diagnosis and switch the ignition off.
If the specified values are not obtained:
Checking primary voltage
- Disconnect the Heated Oxygen Sensor (HO2S) 2 ( G108) electrical harness connector - 1 -.
- Using a multimeter, check the Heated Oxygen Sensor (HO2S) 2 (G108) electrical harness connector terminals 1 to 5 for voltage.
Specified value: 0.400 to 0.500 V
- Switch the ignition off.
If the specified value was not obtained:
- Replace the Heated Oxygen Sensor (HO2S) 2 (G108 ). Refer to Fuel Injection and Ignition Repair Information
If the specified value was obtained:
Checking wiring
If the manufacturers test box is being used, perform the following step.
- Install the test box (VAG1598/31). Refer to Fuel Injection and Ignition Repair Information
If the manufacturers test box is not being used, perform the following step.
- Remove the Motronic Engine Control Module (ECM) ( J220). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.
- Using a Multimeter, check the Heated Oxygen Sensor (HO2S) 2 (G108) electrical harness connector terminals to the Motronic Engine Control Module (ECM) ( J220) electrical harness connector terminals for resistance.
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 found in the wiring:
- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase 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. Refer to => [ 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). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.
- 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. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.
End of diagnosis