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

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:

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 .