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.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

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: 221 ohms (+/- 30 ohm).

If the specified value was not obtained:

-- Replace the Exhaust Gas Temperature Sensor --. Refer to the Repair information.

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).

If any of the specified values were Not obtained:

-- Remove the Motronic Engine Control Module (ECM) -J623-. Refer to the Repair information.

-- 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.

Component	Exhaust Gas Temperature Sensor -- electrical harness connector terminals	Motronic Engine Control Module (ECM) -J623- electrical connector terminals or test box sockets
Exhaust Gas Temperature Sensor 1 -G235-	1	T94/89
	2	T94/31
Exhaust Gas Temperature Sensor 2 -G448-	1	T60/51
	2	T60/55
Exhaust Gas Temperature Sensor 3 -G495-	1	T94/89
	2	T94/32
Exhaust Gas Temperature Sensor 4 -G648-	1	T94/89
	2	T94/9

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 .