GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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


    Object Number: 664520  Size: SH
  1. Turn OFF the ignition.
  2. Drain the cooling system below the level of the ECT sensor. Refer to Cooling System Draining and Filling in Engine Cooling.
  3. Disconnect the ECT electrical connector (2).
  4. Remove the ECT electrical connector from the bracket (1).
  5. Remove the ECT sensor (3).

Installation Procedure


    Object Number: 664520  Size: SH
  1. Coat the threads with sealer P/N 9985253 or equivalent.
  2. Notice: Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

  3. Install the ECT sensor (3)
  4. Tighten
    Tighten the ECT sensor to 20 N·m (15 lb ft).

  5. Connect the ECT electrical connector to the bracket (1).
  6. Connect the ECT harness connector (2) to the ECT sensor (3).
  7. Refill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.