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. Relieve the engine coolant pressure.
3. Drain the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
4. Disconnect the electrical connector.
5. Use a deep well socket and extension in order to remove the engine coolant temperature (ECT) sensor.

1. Coat the ECT sensor threads with sealer GM P/N 9985253, or equivalent.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

2. Install the sensor in engine.

Tighten
Tighten the sensor to 23 N·m (17 lb ft).

3. Connect the electrical connector.
4. Refill the engine coolant to the proper level.
5. Start the engine.
6. Check for coolant leaks.