GM 12641073 Coolant Temperature Sensor

The ECT sensor is installed in the water outlet at the left end of the cylinder head, with some models featuring a second sensor on the passenger's side of the radiator tank. Begin by draining the cooling system to a level below the ECT sensor. For 1.5L engines, remove the turbocharger ducting between the throttle body and charge air cooler. Disconnect the ECT electrical connector and pull the retaining clip to remove the sensor, ensuring to slide the locking tab out first. Inspect the O-ring and replace it if damaged, then reinstall by reversing the removal process and refill the cooling system. For models with a second ECT sensor in the radiator, loosen the right-front wheel lug nuts, raise and support the front of the vehicle on jackstands, and remove the wheel and inner fender splash shield. Locate the sensor in the side of the radiator tank, disconnect the electrical connector, and pull the retaining clip to remove the sensor. Again, inspect the O-ring for damage, replace if necessary, and reinstall while refilling the cooling system afterward.