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.

An 8 digit part identification number is stamped on the bottom of the throttle body casting. Refer to this number if servicing, or part replacement is required.

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. Object Number: 308131  Size: SH
  3. Remove the intake air resonator fastener.

  4. Object Number: 308130  Size: SH
  5. Remove the intake air resonator from the throttle body by pivoting the intake air resonator upward until the hinge clip releases from the lip on the throttle body.

  6. Object Number: 312513  Size: SH
  7. Disconnect the IAC valve harness connector.

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

  10. Object Number: 325550  Size: SH
  11. Remove the cruise control cable.

  12. Object Number: 325556  Size: SH
  13. Remove the accelerator cable.

  14. Object Number: 325557  Size: MH
  15. Remove the cruise control and accelerator cables and the mounting bracket.

  16. Object Number: 424550  Size: SH
  17. Remove the air cleaner adaptor stud.

  18. Object Number: 442105  Size: SH
  19. Remove the throttle body fasteners.

  20. Object Number: 442103  Size: SH
  21. Remove the throttle body assembly.
  22. Remove and discard the flange seal.

Installation Procedure

  1. Clean the seal surface on the intake manifold.

  2. Object Number: 442103  Size: SH
  3. Install a new flange seal.
  4. Install the throttle body assembly.

  5. Object Number: 442105  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.

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


    Object Number: 424550  Size: SH
  8. Install the air cleaner adaptor stud.
  9. Tighten
    Tighten the stud to 8N·m (72 lb in).


    Object Number: 325557  Size: MH
  10. Install the accelerator and cruise control cables and the mounting bracket.

  11. Object Number: 325556  Size: SH

    Important: Make sure the accelerator and cruise control cables are properly routed. Improper routing may cause the throttle plate to remain open.

  12. Install the accelerator cable.

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

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

  17. Object Number: 12886  Size: SH
  18. Connect the IAC valve harness connector.

  19. Object Number: 308130  Size: SH
  20. Install the intake air resonator.
  21. Tighten
    Tighten the fastener to 2 N·m (22 lb in).

  22. Connect the negative battery cable.
  23. Important: The accelerator pedal should operate freely without binding between closed and full throttle.

  24. Depress and release the accelerator pedal to check for binding.