Oxygen Sensor After Catalytic Converter, Checking

Special Tools And Workshop Equipment Required 

• Multimeter.
• Wiring diagram.

Test Requirements 

• HO2S heater fuse is OK. Refer to Appropriate System Diagrams for fuse number.
• 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 .

Start Diagnosis 

-- Perform the function test in Diagnostic Mode 06.

If Specified Mode 6 Values Are Obtained: 

-- Switch the ignition Off. Generate the readiness code.

If The Specified Value Was Not Obtained: 

-- Remove the retaining screws and the cover.

Checking Primary Voltage 

-- Disconnect the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector.

-- 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: 0.40 To 0.50 Volts 

-- Switch the ignition OFF.

If The Specified Value Was Obtained: 

-- Replace the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130-.

If The Specified Value Was Not Obtained: 

Checking Wiring 

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

-- Using a multimeter, check the Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T94 terminals for resistance. Refer to Appropriate System Diagrams for pin locations.

2009 - 2010 Models 

Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -G130- electrical harness connector terminals:	Engine Control Module (ECM) -J623- electrical connector T94 terminals:
3	71
4	62

2011 > 

Oxygen Sensor (O2S) Behind Three Way Catalytic Converter (TWC) -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 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-.

-- 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 .
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 .