Oxygen Sensor After Three Way Catalytic Converter, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The fuses OK.
• Oxygen Sensor (O2S) 1 (behind Three Way Catalytic Converter Heater -Z29- 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, selector lever in position "P" or "N".
• A/C switched off.
• Ground 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 

Start diagnosis 

-- Connect scan tool.

-- Start the engine and let it run at 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".

-- Check the specified values with engine idling.

-- Switch the ignition Off.

If the specified values were 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 values were Not obtained: 

-- Remove the right vehicle floor cover.

Checking voltages 

-- Switch the ignition On.

-- Using a Multimeter, check the Oxygen Sensor After Three Way Catalytic Converter -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 After Three Way Catalytic Converter -G130-.

If the specified value was not obtained: 

Checking wiring 

-- Remove the Engine Control Module (ECM) -J623-.

-- Using a Multimeter, check the Oxygen Sensor After Three Way Catalytic Converter -G130- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T94 terminals for an open circuit.

Oxygen Sensor After Three Way Catalytic Converter -G130- electrical harness connector terminals:	Engine Control Module (ECM) -J623- electrical connector T94 terminals:
3	72
4	84

Specified value: 1.5 Ω 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, lose or broken terminals.

-- If necessary, repair the faulty wiring connection.

If the specification was obtained: 

-- Replace the Engine Control Module (ECM) -J623-.

Final procedures 

-- Install the right vehicle floor cover.

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 .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .