Oxygen Sensor Heater Behind Catalytic Converter, Checking

Oxygen Sensor Heater Behind Catalytic Converter, Checking

• Vehicle must be raised before electrical harness connector for the Oxygen Sensor Behind Three Way Catalytic Converter (G130) is accessible.

• When servicing terminals in harness connector of Oxygen Sensor Behind Three Way Catalytic Converter (G130), use only gold-plated terminals.

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• The Oxygen Sensor Behind Three Way Catalytic Converter (G130) fuse is 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 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

- Remove the right vehicle floor cover - arrows -.





Checking internal resistance

- Disconnect the Oxygen Sensor Behind Three Way Catalytic Converter (G130) electrical harness connector - arrow -.





- Using a multimeter, check the Oxygen Sensor Behind Three Way Catalytic Converter (G130) electrical harness connector terminals 1 to 2 for resistance.





Specified value: 1.0 to 20.0 ohms (at approx. 20° C)

If the specified value was Not obtained:

- Replace the Oxygen Sensor Behind Three Way Catalytic Converter (G130). Refer to the Repair Information.

If the specified value was obtained:

Checking voltage supply

- Turn the ignition switch ON

- Using a multimeter, check the Oxygen Sensor Behind Three Way Catalytic Converter (G130) electrical harness connector terminal 1 to engine ground.

- Turn the ignition switch OFF.

Specified value: Battery voltage.

If the specified value was Not obtained:

- Check the wiring from O2 heater fuse in Fuse Panel B to terminal 1 of the Oxygen Sensor Behind Three Way Catalytic Converter (G130) for an open, high resistance, short circuit or Ground. Refer to Wiring Diagrams for fuse number.

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

Checking Ground activation

- Remove the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Using a multimeter, check the Oxygen Sensor Behind Three Way Catalytic Converter (G130) electrical harness connector terminal 2 to the Engine Control Module (ECM) (J623) electrical harness connector T94 terminal 29 for an open circuit according to the wiring diagram.





Specified value: 1.5 ohms max.

If the specified value was Not obtained:

- Check the wiring for an open or high resistance.

- 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:

- Replace the Engine Control Module (ECM) (J623). Refer to the Repair Information.

- Install the right vehicle floor cover.

Final procedures

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 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.