GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

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


    Object Number: 1889684  Size: SH
  1. Drain the cooling system. Refer to Cooling System Draining and Filling.
  2. Disconnect the engine wiring harness electrical connector (1) from the engine coolant temperature (ECT) sensor (2).

  3. Object Number: 1889685  Size: SH
  4. Remove the ECT sensor (1) from the thermostat housing.

Installation Procedure

Caution: 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.

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


    Object Number: 1889685  Size: SH
  1. If reinstalling the original sensor, or if installing a NEW sensor without a sealer, coat the threads with sealant. Refer to Adhesives, Fluids, Lubricants, and Sealers.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the ECT sensor (1) to the thermostat housing and tighten the sensor to 20 N·m (15 lb ft).

  4. Object Number: 1889684  Size: SH
  5. Connect the engine wiring harness electrical connector (1) to the ECT sensor (2).
  6. Fill the cooling system. Refer to Cooling System Draining and Filling.