Oxygen Sensor in Center Catalytic Converter, Checking (CBUA Only)

Oxygen Sensor in Center Catalytic Converter, Checking (CBUA Only)

• Use only gold-plated terminals when servicing terminals in the electrical harness connectors of the Oxygen Sensor (O2S) 2 in center Three Way Catalytic Converter (TWC) (G465).

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirements

• O2 heater fuse is OK.

• Engine Control Module (ECM) (J623) 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 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.

If specified values are obtained:

- Check for possible intermittent connection or rub through of harness.

If the specified values are Not obtained:

Checking primary voltage

- Disconnect the Oxygen Sensor (O2S) 2 in center Three Way Catalytic Converter (TWC) (G465) electrical harness connector.

- Switch the ignition On.

- Using a multimeter, check the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) (G465) electrical harness connector terminals 3 to 4 for voltage.

Specified value: 0.40 to 0.50 Volts

- Switch the ignition Off.

If the specified value was obtained:

- Replace the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) (G465).

If the specified value was Not obtained:

Checking wiring

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

- Using a multimeter, check the Oxygen Sensor (O2S) 2 Behind Three Way Catalytic Converter (TWC) (G465) electrical harness connector terminals to the Engine Control Module (ECM) (J623) electrical harness connector T94 terminals for resistance. Refer to Wiring Diagrams for pin locations.

2009 - 2010 Models






2011 >






Specified value: 1.5 ohms Max.

If the specified value was Not obtained:

- Check the wiring for an open, high resistance, short circuit to each other, Battery (+) or Ground.

- 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 the voltage supply was Not OK:

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

- 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 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.