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

1. Turn OFF the ignition.
2. Drain the coolant system to below the engine coolant temperature (ECT) sensor. Refer to Cooling System Draining and Filling .
3. Disconnect the engine coolant temperature ECT sensor electrical connector.
4. Carefully remove the ECT sensor (1).

Notice: 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.

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

1. If you are reinstalling the original sensor, or if you are installing a new sensor without a sealer, coat the threads with sealer GM P/N 21485227, LOCTITE® 242 Threadlocker or an equivalent.

Notice: Refer to Fastener Notice in the Preface section.

2. Install the ECT sensor (1).

Tighten
Tighten the ECT sensor to 22 N·m (16 lb ft).

3. Connect the ECT sensor electrical connector.
4. Refill the engine coolant system. Refer to Cooling System Draining and Filling .