Oxygen Sensor Heater Bank 2 Sensor 1, Checking
Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- is part of HO2S Oxygen Sensor Bank 2 Sensor 1 -G108- and cannot be serviced separately.
When servicing terminals in the electrical harness connector of HO2S Oxygen Sensor Bank 2 Sensor 1 -G108-, use only gold-plated terminals. No attempt should be made to repair wiring or terminals on the sensor itself. Replacement of the sensor is required in that instance.
Special tools and workshop equipment required
- Multimeter.
- Wiring diagram.
Test requirements
- Fuse -SB 33- fuse 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.
The voltage for the Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- is supplied by the Engine Control Module (ECM) Power Supply Relay -J271- through fuse S-17 to the heater.
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 .
Start diagnosis
-- Disconnect the HO2S Oxygen Sensor Bank 2 Sensor 1 -G108- electrical harness connector -4-.
Checking internal resistance
-- Using a multimeter, check the Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- terminals 3 to 4 for resistance.
Specified value: 2.0 to 10.0 Ω (at approx. 20° C)
If the specification was Not obtained:
-- Replace HO2S Oxygen Sensor Bank 2 Sensor 1 -G108-. Refer to the Repair Information.
If the specification was obtained:
Checking voltage supply
Start the engine.
-- Using a multimeter, check the Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- electrical harness connector terminal to ground for voltage.
| Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- electrical harness connector terminal | Measure to: |
|---|---|
| 4 | Ground |
Specified value: above 10.0 V.
Switch the ignition OFF.
If the specification was Not obtained:
-- Check the Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- electrical harness connector terminal 4 to fuse S-17 for high resistance, a short to ground, or an open circuit.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection and replace any blown fuse.
If the specification was 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 Engine Control Module (ECM) -J623-. Refer to the Repair Information.
-- Using a multimeter, check the Oxygen Sensor Heater Bank 2 Sensor 1 -Z28- electrical harness connector to the Engine Control Module (ECM) -J623- electrical harness connector T94 for an open circuit.
| HO2S Oxygen Sensor Bank 2 Sensor 1 -G108- electrical harness connector terminal | Engine Control Module (ECM) -J623- electrical connector T94 terminal or test box socket |
|---|---|
| 3 | 73 |
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.
If no malfunction is detected in the wiring and the heater resistance and voltage supply is 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 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 .