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) -J220-. 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 T121 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) -J220-. Refer to appropriate service information.
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 .