Testing if display approx. 140.0°C

-- Disconnect the Engine Coolant Temperature (ECT) Sensor -G62- electrical harness connector -arrow-.

If indication jumps to approx. -40.0° C:

-- End diagnosis and switch ignition off.

-- Replace the Engine Coolant Temperature (ECT) Sensor - G62-. Refer to appropriate service information.

If indication remains at approx. 140.0° C:

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-. Refer to appropriate service information.

-- Using a multimeter, check the Engine Coolant Temperature (ECT) Sensor - G62- electrical harness connector terminals to the Motronic Engine Control Module (ECM) -J220- electrical harness connector T121 terminals for an open circuit according to the wiring diagram.

Engine Coolant Temperature (ECT) Sensor - G62- electrical harness connector terminals	Motronic Engine Control Module (ECM) -J220- electrical connector T60 terminals or test box socket
1	93
2	108

Specified value: 1.5 Ω Max.

If the specification was not obtained:

-- Check the wiring for a short circuit to Battery (+), or an open circuit.

-- 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:

-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to appropriate service information.

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 .