Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ho2S Rear Oxygen Sensor Bank 1 Sensor 2, Checking
Vehicle must be raised before the electrical connector of the HO2S Oxygen Sensor Bank 1 Sensor 2 -G130- is accessible.
When servicing terminals 3 and 4 in the electrical harness connector of the HO2S Oxygen Sensor Bank 1 Sensor 2 -G130-, use only gold-plated terminals.
Special tools and workshop equipment required
- Multimeter.
- Wiring diagram.
Test requirements
- The HO2S Oxygen Sensor Bank 1 Sensor 2 -G130- fuse OK.
- Oxygen Sensor Heater Bank 1 Sensor 2 - Z29- 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
-- Observe safety precautions. Refer to SAFETY PRECAUTIONS
-- Observe Clean Working Conditions. Refer to CLEAN WORKING CONDITIONS
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .
Function test
-- Perform the function test in Diagnostic Mode 06. Refer to DIAGNOSTIC MODE 06 - READ TEST RESULTS FOR SPECIFIC DIAGNOSTIC FUNCTIONS .
-- Switch ignition off.
If the specified values are not obtained:
Start diagnosis
-- Disconnect the HO2S Oxygen Sensor Bank 1 Sensor 2 -G130- electrical harness connector -1-.
Checking primary voltage
-- Switch the ignition on.
-- Using a multimeter, check the HO2S Oxygen Sensor Bank 1 Sensor 2 -G130- electrical harness connector terminals 3 to 4 for voltage.
Specified value: 4.10 to 5.00 V
-- Switch the ignition off.
If the specified value was obtained:
-- Replace the HO2S Oxygen Sensor Bank 1 Sensor 2 -G130-.
If the specified value was not obtained:
Checking wiring
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 Motronic Engine Control Module (ECM) -J623-.
-- Using a multimeter, check the HO2S Oxygen Sensor Bank 1 Sensor 2 -G130- electrical harness connector terminals to the Motronic Engine Control Module (ECM) -J220- electrical harness connector T94 terminals for an open circuit.
| HO2S Oxygen Sensor Bank 1 Sensor 2 -G130- electrical harness connector terminals | Motronic Engine Control Module (ECM) -J623- electrical connector T94 terminals or test box sockets |
|---|---|
| 3 | 76 |
| 4 | 77 |
Specified value: 1.5 Ω Max.
If the specification was not obtained:
-- Check the wiring for high resistance, an open or a short to voltage or ground.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
-- Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
-- Perform a road test to verify repair.
If the DTC does not return:
Generate readiness code. Refer to READINESS CODE .
If the DTC does return, no malfunction is detected in the wiring and the voltage supply is OK:
-- Replace the Motronic 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 mentioned sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.
