GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Terraza Ext. 🢒 Engine 🢒 Engine Controls - 3.9L 🢒 Throttle Body Assembly Replacement

Removal Procedure

Notice: Handle the electronic throttle control components carefully. Use cleanliness in order to prevent damage. Do not drop the electronic throttle control components. Do not roughly handle the electronic throttle control components. Do not immerse the electronic throttle control components in cleaning solvents of any type.

Important: 

   • DO NOT for any reason, insert a screwdriver or other small hand tool into the throttle body to hold open the throttle plate as a wedge, as the inside of the throttle body could be damaged.
   • An 8-digit part identification number is stamped on the throttle body casting. Refer to this number if servicing, or part replacement is required.


    Object Number: 1675738 Size: SH
  1. Remove the intake manifold cover. Refer to Intake Manifold Cover Replacement .
  2. Drain the engine cooling. Refer to Cooling System Draining and Filling .
  3. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .
  4. Disconnect the engine harness electrical connector (2) from the electronic throttle control (ETC).

    5. Object Number: 1675739 Size: SH
  5. Remove the heater inlet and outlet pipe clip nuts (1) from the throttle body studs.
  6. Reposition the heater inlet and outlet hose clamps at the engine pipes.
  7. Reposition the heater inlet and outlet hose/pipe (2, 3).

    8. Object Number: 1614648 Size: SH
  8. Remove the throttle body bolts/nuts.
  9. Remove the throttle body.
  10. Remove and discard the throttle body gasket.

Installation Procedure

Important: DO NOT reuse the throttle body gasket. Install a NEW gasket during assembly.


    Object Number: 1614648 Size: SH
  1. Install a NEW throttle body gasket. Align the locating tab of the gasket with the notch in the manifold.
  2. Position the throttle body to the intake manifold.

    3. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the throttle body bolts/nuts.

    4. Tighten
    Tighten the bolts/nuts to 10 N·m (89 lb in).


    Object Number: 1675739 Size: SH
  4. Position the heater inlet and outlet hose/pipe (2, 3).
  5. Position the heater inlet and outlet hose clamps at the engine pipes.
  6. Install the heater inlet and outlet pipe clip nuts (1) to the throttle body studs.

    7. Tighten
    Tighten the nuts to 10 N·m (89 lb in).


    Object Number: 1675738 Size: SH

    Important: Verify that the throttle actuator motor harness connector and the connector seal are properly installed and not damaged.

  7. Connect the engine harness electrical connector (2) to the ETC.
  8. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .
  9. Fill the engine cooling. Refer to Cooling System Draining and Filling .
  10. Install the intake manifold cover. Refer to Intake Manifold Cover Replacement .
  11. Connect a scan tool in order to test for proper throttle opening and throttle closing ranges.
  12. Operate the accelerator pedal and monitor the throttle angles. The accelerator pedal should operate freely, without binding, between closed throttle, and wide open throttle (WOT).
  13. Verify that the vehicle meets the following conditions:
    14. • The vehicle is not in a reduced engine power mode.
    • The ignition is ON.
    • The engine is OFF.