Coolant Temperature Sensor/Switch (For Computer): Service and Repair

Engine Coolant Temperature Sensor Replacement

Removal Procedure




1. Drain the engine coolant to a level below the engine coolant temperature (ECT) sensor. Refer to Cooling System Draining and Filling (LNJ Static Fill) Cooling System Draining and Filling (LNJ GE 47716 Fill) Cooling System Draining and Filling (LY7 Static Fill) Cooling System Draining and Filling (LY7 GE 47716 Fill).
2. Remove the fuel injector sight shield.
3. Disconnect the ECT sensor harness connector.
4. Remove the ECT sensor.

Installation Procedure

Important: Tap out sensor mounting hole in engine head to remove any thread sealant residue. Clean any sealant residue from old sensor if the sensor is going to be reused.




1. If the sensor is being reused, apply thread sealant GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to sensor threads.

Notice: Refer to Component Fastener Tightening Notice.

2. Install the ECT sensor.

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

3. Connect the ECT sensor harness connector. Push in the connector until a click is heard, then pull back to confirm a positive engagement.
4. Install the fuel injector sight shield.
5. Fill the engine cooling system to proper level. Refer to Cooling System Draining and Filling (LNJ Static Fill) Cooling System Draining and Filling (LNJ GE 47716 Fill) Cooling System Draining and Filling (LY7 Static Fill) Cooling System Draining and Filling (LY7 GE 47716 Fill).