GM Service Manual Online
For 1990-2009 cars only

Cleaning Procedure

Notice: Do not subject a throttle body assembly which contains the following components to an immersion cleaner or a strong solvent:

   • Throttle position (TP) sensor
   • Idle air control (IAC) valve
   • Sealed throttle shaft bearings
The cleaners will damage the electric components or sensors.

The cleaners will damage some of these components that contain seals or O-rings.

Solvents can wash away or break down the grease used on non-serviceable throttle shaft bearings.

Never use a wire brush or scraper to clean the throttle body. A wire brush or sharp tools may damage the throttle body components.

Do not use a cleaner that contains methyl ethyl ketone. This extremely strong solvent may damage components and is not necessary for this type of cleaning.

Clean the throttle body bore and throttle valve plate on the vehicle using a clean shop towel with GM Top Engine Cleaner, P/N 1052626 or AC-Delco Carburetor Tune-Up Conditioner, P/N X66P, or equivalent. Remove and disassemble the throttle body for cleaning if the deposits are excessive. Refer to Idle Air Control Valve Replacement for IAC valve removal and Throttle Position Sensor Replacement for TP sensor removal. After disassembly, clean the throttle body using a parts cleaning brush. DO NOT immerse the throttle body in any cleaning solvent.

Removal Procedure

    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. Remove the engine cover. Refer to Engine Cover Replacement in Interior Trim.

  3. Object Number: 35885  Size: SH
  4. Remove the air cleaner outlet retaining nut (1).
  5. Remove the air cleaner outlet duct (2) from the throttle body assembly.

  6. Object Number: 423117  Size: SH
  7. Disconnect the IAT sensor harness connector.

  8. Object Number: 422129  Size: SH
  9. Loosen the air cleaner outlet duct from the MAF sensor.
  10. Remove the air cleaner outlet duct.

  11. Object Number: 424550  Size: SH
  12. Remove the air cleaner outlet duct adapter stud.

  13. Object Number: 325550  Size: SH
  14. Remove the cruise control cable.

  15. Object Number: 325556  Size: SH
  16. Remove the accelerator cable.
  17. Remove the stud and nuts retaining the accelerator control cable bracket and position bracket aside.

  18. Object Number: 312513  Size: SH
  19. Disconnect the IAC valve harness connector.

  20. Object Number: 12885  Size: SH
  21. Disconnect the TP sensor harness connector.

  22. Object Number: 12852  Size: SH
  23. Remove the throttle body retaining studs.

  24. Object Number: 12853  Size: SH
  25. Remove the throttle body assembly.
  26. Discard the throttle body seal.

Installation Procedure

  1. Clean the gasket surface on the intake manifold.

  2. Object Number: 12853  Size: SH
  3. Install the throttle body assembly with a new seal.

  4. Object Number: 12852  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.

  5. Install the throttle body assembly retaining studs.
  6. Tighten
    Tighten the studs to 9 N·m (80 lb in).


    Object Number: 424550  Size: SH
  7. Install the air cleaner outlet duct adapter stud.
  8. Tighten
    Tighten the stud to 8 N·m (72 lb in).


    Object Number: 12885  Size: SH
  9. Connect the TP sensor harness connector.

  10. Object Number: 312513  Size: SH
  11. Connect the IAC valve harness connector.
  12. Install the accelerator control cable bracket using the fasteners.
  13. Tighten
    Tighten the fasteners to 12 N·m (108 lb in).


    Object Number: 325556  Size: SH

    Important: Make sure the accelerator and the cruise control cables do not hold the throttle open.

  14. Install the accelerator cable.

  15. Object Number: 325550  Size: SH
  16. Install the cruise control cable.

  17. Object Number: 422129  Size: SH
  18. Install the air cleaner outlet duct to the MAF sensor.

  19. Object Number: 423117  Size: SH
  20. Connect the IAT sensor harness connector.

  21. Object Number: 35885  Size: SH
  22. Install the air cleaner outlet duct (2) on the throttle body assembly.
  23. Tighten the retaining nut (1).
  24. Tighten
    Tighten the nut 2 N·m (18 lb in).

  25. Install the engine cover. Refer to Engine Cover Replacement in Interior Trim.
  26. Connect the negative battery cable.
  27. Important: The accelerator pedal should operate freely without binding between full and closed throttle.

  28. Check the accelerator pedal for proper operation.