Oxygen Sensor O2S Behind Three Way Catalytic Converter, Checking
Oxygen Sensor O2S Behind Three Way Catalytic Converter, Checking
Observe all safety precautions: => [ Safety Precautions ] Safety Precautions
View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions
For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.
• For connector location, removal and installation procedures. Refer to the appropriate service manual.
• When servicing terminals in the electrical harness connector of the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130) ,and Oxygen Sensor O2S Behind Three Way Catalytic Converter Heater (Z29) use only gold-plated terminals.
Special tools, testers and auxiliary items required
• Generic scan tool
• Multimeter.
• Wiring diagram.
Test requirements
• The Oxygen Sensor O2S Behind Three Way Catalytic Converter Heater (Z29) fuse Ok.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• Vehicles with automatic transmission, selector lever in position "P" or "N".
• A/C switched off.
• Ground (GND) connections between engine/transmission/chassis OK.
• Exhaust system between catalytic converter and cylinder head properly sealed.
• Coolant Temperature at least 80° C.
Test procedure
- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check
Start diagnosis
- Connect scan tool.
- Start the engine and let idle.
- Select "Diagnostic mode 6: Check test results of components that are not continuously monitored".
- Select "Test-ID 02: Oxygen sensor monitoring behind catalytic converter".
- Select following Test-IDs.
- Check the specified values at idle.
- Switch the ignition OFF.
If the specified value was obtained:
- Fault may be intermittent.
- Check for loose or corroded connections and any leaks in the exhaust.
- Check Freeze Frame data for conditions when the DTC set.
- Go to Final procedures
If the specified value was Not obtained:
- For connector location, removal and installation procedures. Refer to the appropriate service manual.
- Remove the engine cover. Refer to the appropriate service manual.
- Disconnect the connector -1- from the Mass airflow sensor (G70) , and remove the Air Filter Housing. Refer to appropriate service manual.
Checking primary voltage
- Disconnect the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130) electrical harness connector - 2 -.
- Switch the ignition ON.
- Using a Multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130) electrical harness connector terminals 3 to 4 for voltage.
Specified value: 0.400 to 0.500 Volts
- Switch the ignition OFF.
If the specified value was obtained:
- Replace the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130). Refer to the appropriate service manual.
- Go to Final procedures
If the specified value was Not obtained:
Checking wiring
- Remove the Motronic Engine Control Module (ECM) (J623). Refer to the appropriate service manual.
- Using a Multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) (G130) electrical harness connector terminals to the Motronic Engine Control Module (ECM) (J623) electrical harness connector T94 terminals for an open circuit according to the wiring diagram.
Specified value: 1.5 ohms Max.
If the specified value was Not obtained:
- Check the circuits for a short to each other, short to battery voltage, and short to ground.
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- Repair the wiring or connection as necessary.
- Go to Final procedures
If the specified value was obtained:
- Replace the Motronic Engine Control Module (ECM) (J623). Refer to the appropriate service manual.
Final procedures
- Reinstall the engine cover and Air Filter Housing, if necessary. Refer to the appropriate service manual.
- For connector location, removal and installation procedures. Refer to the appropriate service manual.
- After the 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 Modes 01 - 0A.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 0A.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Programming and Relearning.