Testing if display approx. 140.0 °C
-- Disconnect the Engine Coolant Temperature (ECT) Sensor - G62 or 83- electrical harness connector.
-- Turn the ignition switch ON.
If indication jumps to approx. - 40.0 °C:
-- Switch ignition OFF.
-- Replace the Engine Coolant Temperature (ECT) Sensor - G62 or 83- Refer to the Repair information.
If the value remains at approx. 140.0 °C
Checking wiring
-- Remove the Engine Control Module (ECM) -J623- and disconnect the ECM connectors. Refer to the Repair information.
-- Disconnect the ECT harness connector at the sensor.
-- Using a multimeter, check the signal circuit of the Engine Coolant Temperature (ECT) Sensor - G62 or 83- electrical harness connector terminal 1 to engine ground.
Specified value: OL or no continuity.
If the specified value was Not obtained:
-- Check the wiring for a short circuit to Ground.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
If the specified value was obtained:
-- Replace the Engine Control Module (ECM) -J623-. Refer to the Repair 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 .