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. Refer to Cooling System Draining and Filling in Engine Cooling.
3. Disconnect the engine coolant temperature (ECT) sensor connector.
4. Remove the ECT sensor.

1. Coat the threads only of the ECT sensor with thread sealer GM P/N 9985253 or equivalent if the new sensor does not have sealer.
2. Install the ECT sensor into the engine.
3. Connect the ECT sensor connector.
4. Refill the engine coolant system. Refer to Cooling System Draining and Filling in Engine Cooling.
5. Inspect for leaks.