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.
Exhaust Gas Temperature Sensor 1 - 4, Checking
Observe all safety precautions: SAFETY PRECAUTIONS
View clean working conditions: CLEAN WORKING CONDITIONS
Perform a preliminary check to verify the condition: PRELIMINARY CHECK .
Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.
See Appropriate Wiring Diagram Information for component locations and connector views.
Special Tools And Workshop Equipment Required
- Multimeter
- Electrical connector test lead set
Test Conditions
- Battery voltage 12.5 V
- Fuse OK
- Ignition switched off
The engine MUST be at room temperature to read the resistance of the Exhaust Gas Temperature Sensor. Exhaust system must be cool to touch.
Test Procedure
-- Disconnect the Exhaust Gas Temperature Sensor -- harness connector.
-- Measure the resistance of the 2 terminals of the Exhaust Gas Temperature Sensor -- connector.
Specified Value: 215 Ohms (+/- 25 Ohm).
If The Specified Value Was Not Obtained:
-- Replace the Exhaust Gas Temperature Sensor --.
If The Specified Value Was Obtained:
-- Connect the voltmeter to terminal 1 of the Exhaust Gas Temperature Sensor -- harness connector and ground black lead to engine.
-- Turn the ignition switch ON.
Specified Value: 3.35 V (+/-.5 V).
If The Specified Value Was Obtained:
-- Leave the red lead on terminal 1 and connect the black lead to terminal 2.
Specified Value: 3.35 V (+/-.5 V).
-- Turn the ignition switch Off.
If Any Of The Specified Values Were Not Obtained:
-- Remove the Motronic Engine Control Module (ECM) -J623-.
-- Using a multimeter, check the Exhaust Gas Temperature Sensor -- electrical harness connector terminals to the Motronic Engine Control Module (ECM) -J623- electrical harness connector T94 connector for resistance. Refer to Appropriate Wiring Diagrams for Pin locations.
| Component | Exhaust Gas Temperature Sensor -- electrical harness connector terminals | Motronic Engine Control Module (ECM) -J623- electrical connector T94 terminals |
|---|---|---|
| Exhaust Gas Temperature Sensor 1 -G235- | 1 | 89 |
| 2 | 9 | |
| Exhaust Gas Temperature Sensor 2 -G448- | 1 | 89 |
| 2 | 31 | |
| Exhaust Gas Temperature Sensor 3 -G495- | 1 | 89 |
| 2 | 32 | |
| Exhaust Gas Temperature Sensor 4 -G648- | 1 | 89 |
| 2 | 75 |
Specified Value: 1.5 Ohms Max.
If Any Of The Specified Values Were Not Obtained:
-- Check the wires for a short circuit to each other, a short to battery voltage, or a short to ground.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- Repair as necessary.
If No Malfunction Is Detected In Electrical Circuit:
-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to the Repair information for removal and installation procedures.
Final Procedures
After the repair work, the following work steps must be performed in the following 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
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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.
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