Before changing the Engine Coolant Temperature (ECT) Sensor, OFF the ignition and lift the vehicle. Lower the car and drain the cooling system below the level of the ECT sensor. Unplug the electrical connector from the ECT sensor and pull it out. For installation, verify part number for replacement is correct for the application and any needed thread locking compound, lubricants, corrosion inhibitors or sealants are applied as per specification. Apply sealer (GM P/N 12346004 or equivalent) onto the ECT sensor threads before installation, and tighten this sensor to 20 N.m (15 lb ft). Finally, connect the ECT sensor electrical connection and fill up the engine coolant.