Testing if display approx. 140.0°C

-- Disconnect the Engine Coolant Temperature (ECT) Sensor -G62 or G83- 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 G83-.

If indication remains at approx. 140.0° C:

Checking wiring 

-- Remove the Engine Control Module (ECM) -J623-. 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 G83- electrical harness connector terminal 1 to engine ground. Refer to Wiring Diagrams for pin locations.

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 no malfunction is detected in the wiring:

-- 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:

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 .