For 1990-2009 cars

### Removal Procedure

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

1. Turn the ignition switch OFF.
2. Drain the coolant system. Refer to Cooling System Draining and Filling in Engine Cooling.
3. Disconnect the ECT sensor electrical connector.
4. Carefully back out the ECT sensor.

### Installation Procedure

1. Coat only the threads of the ECT sensor with thread sealer GM P/N 9985253 or equivalent.
2. Install the ECT sensor in the engine, fully driven, seated and not stripped.
3. Connect the ECT sensor electrical connector.
4. Refill the engine coolant system. Refer to Cooling System Draining and Filling in Engine Cooling.