Coolant Temperature Sensor/Switch (For Computer): Service and Repair

Engine Coolant Temperature Sensor Replacement

Removal Procedure

1. Turn OFF the ignition.

Danger: To avoid any vehicle damage, serious personal injury or death when major components are removed from the vehicle and the vehicle is supported by a hoist, support the vehicle with jack stands at the opposite end from which the components are being removed and strap the vehicle to the hoist.


2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle (Service and Repair).
3. Drain the engine coolant below the level of the engine coolant temperature (ECT) sensor. Refer to Cooling System Draining and Filling (LS3, L99 Static Fill) (Cooling System Draining and Filling (Static Fill))Cooling System Draining and Filling (LLT Static Fill) (Cooling System Draining and Filling (Static Fill))Cooling System Draining and Filling (GE 47716) (Cooling System Draining and Filling (GE 47716)).
4. Lower the vehicle.




5. Disconnect the ETC wiring harness connector (1) from the ECT sensor.





Caution: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

6. Remove the ECT sensor (1) from the cylinder head.

Installation Procedure

Caution: Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

Caution: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

1. Coat the ECT sensor threads with sealer or the equivalent.





Caution: Refer to Fastener Caution (Fastener Caution).

2. Install the ECT sensor (1) to the cylinder head and tighten to 20 Nm (15 lb ft).




3. Connect the ETC wiring harness connector (1) ECT sensor.
4. Refill the engine coolant. Refer to Cooling System Draining and Filling (LS3, L99 Static Fill) (Cooling System Draining and Filling (Static Fill))Cooling System Draining and Filling (LLT Static Fill) (Cooling System Draining and Filling (Static Fill))Cooling System Draining and Filling (GE 47716) (Cooling System Draining and Filling (GE 47716)).