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.

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.
  2. Caution: To avoid being burned, do not remove the radiator cap or surge tank cap while the engine is hot. The cooling system will release scalding fluid and steam under pressure if radiator cap or surge tank cap is removed while the engine and radiator are still hot.

  3. Relieve the cooling system pressure.
  4. Drain the cooling system below the level of the ECT sensor. Refer to Cooling System Draining and Filling in Engine Cooling.

  5. Object Number: 315643  Size: SH
  6. Disconnect the ECT sensor harness connector.

  7. Object Number: 300493  Size: SH
  8. Remove the ECT sensor.

Installation Procedure

  1. Coat the threads (only) with sealer P/N 9985253 or equivalent.

  2. Object Number: 300493  Size: SH

    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.
  4. Tighten
    Tighten the ECT sensor to 13 N·m (10 lb ft).


    Object Number: 315643  Size: SH
  5. Connect the ECT sensor harness connector.
  6. Refill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  7. Connect the negative battery cable.