GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2003 🢒 Envoy - 2WD 🢒 Engine 🢒 Engine Controls - 4.8L, 5.3L, and 6.0L 🢒 Engine Coolant Temperature Sensor Replacement

Removal Procedure

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

  1. Turn OFF the ignition.

    2. Object Number: 898343 Size: SH
  2. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  3. Drain the cooling system below the level of the ECT sensor. Refer to Cooling System Draining and Filling in Engine Cooling.
  4. Lower the vehicle.
  5. Disconnect the engine coolant temperature (ECT) sensor electrical connector (1).

    6. Object Number: 50974 Size: SH
  6. Remove the ECT sensor.

Installation Procedure

    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.

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

  1. Coat the ECT sensor threads with sealer GM P/N 12346004 (Canadian P/N 10953480), or equivalent.

    2. Object Number: 50974 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  2. Install the ECT sensor.

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


    Object Number: 898343 Size: SH
  3. Connect the ECT sensor electrical connector (1).
  4. Refill the engine coolant. Refer to Cooling System Draining and Filling in Engine Cooling.