Oxygen Sensor 2 After Catalytic Converter, Checking Heater
Oxygen Sensor 2 After Catalytic Converter, Checking Heater
The following procedure is used to diagnose Oxygen Sensor (O2S) 2 (behind Three Way Catalytic Converter (TWC)) Heater Z30 for Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 which is controlled by the Engine Control Module (ECM) 2 J624.
NOTE: When servicing terminals in harness connector of Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) use only gold-plated terminals.
Special tools, testers and auxiliary items required
- Multimeter.
- Wiring diagram.
Test requirements
- Fuse S73 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
- Raise the vehicle.
- Disconnect the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 electrical harness connector - 3 -.
Checking internal resistance
- 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
- Crank the engine.
- 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.
Oxygen Sensor (O2S) 2 Behind Measure to
Three Way Catalytic Converter
(TWC) G131 electrical harness
connector terminal
1 Ground (GND)
Specified value: Battery voltage.
- Switch the ignition off.
If the specification was not obtained:
- Check the wiring from the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 electrical harness connector terminal 1 to the Engine Component Power Supply Relay J757 socket 2/87 for a short circuit to each other, Ground (GND) or an open circuit.
- Check the electrical harness connector for damage, corrosion, lose 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.
If the manufacturers test box is not being used. Perform the following step.
- Remove the Engine Control Module (ECM) 2 J624.
- Using a multimeter , check the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) G131 electrical harness connector to the Engine Control Module (ECM) 2 J624 electrical harness connector T94a for an open circuit.
Oxygen Sensor (O2S) 2 Behind Engine Control Module (ECM) 2
Three Way Catalytic Converter J624 electrical connector T94a
(TWC) G131 electrical harness terminal or test box socket
connector terminal
2 7
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).
- If necessary, repair the faulty wiring connection.
If no malfunction is detected in the wiring and if the voltage supply was OK:
- Replace the Engine Control Module (ECM) 2 J624.
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. Monitors, Trips, Drive Cycles and Readiness Codes
- End of diagnosis.