GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2009 🢒 Optra - Mexico 🢒 Engine 🢒 Engine Controls and Fuel - 1.8L (L79) 🢒 Throttle Body Assembly Replacement

Removal Procedure

    Warning: Refer to Battery Disconnect Warning in the Preface section.


    Object Number: 1289506 Size: SH
  1. Disconnect the negative battery cable.
  2. Disconnect the intake air temperature (IAT) sensor connector.
  3. Disconnect the breather hose from the valve cover.
  4. Remove the air intake tube.

    5. Object Number: 1256155 Size: SH
  5. Disconnect the throttle cables by opening the throttle and moving the cable through the release slot.
  6. Disconnect the vacuum hoses from the throttle body.
  7. Disconnect the throttle position (TP) sensor and the idle air control (IAC) valve connectors.
  8. Disconnect the coolant hoses from the throttle body.
  9. Remove the throttle body retaining nuts.

    10. Object Number: 1256156 Size: SH

    Caution: Mask off the ports to the intake manifold spacer. Failure to mask off the ports may allow foreign objects to enter the engine resulting in severe damage to the engine.

  10. Remove the throttle body and discard the gasket.
  11. Remove the TP sensor. Refer to Throttle Position Sensor Replacement.
  12. Remove the IAC valve. Refer to Idle Air Control Valve Replacement.

Installation Procedure

    Warning: Refer to Safety Glasses Warning in the Preface section.


    Object Number: 1256155 Size: SH

    Caution: Use care when cleaning the old gasket from the aluminum surfaces in order to prevent damage to the sealing surfaces.

  1. Clean the gasket mating surface on the intake manifold.

    2. Caution: 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.

    Caution: 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.

  2. Clean the throttle body.
  3. Install the TP sensor. Refer to Throttle Position Sensor Replacement.
  4. Install the IAC valve. Refer to Idle Air Control Valve Replacement.
  5. Install the throttle body assembly with a new gasket to the intake manifold.

    6. Caution: Refer to Fastener Caution in the Preface section.

  6. Install the throttle body retaining nuts.

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


    Object Number: 1289506 Size: SH
  7. Connect the TP sensor connector and the IAC valve connector.
  8. Connect the coolant hoses to the throttle body.
  9. Connect the vacuum hoses to the throttle body.

    10. Note: Make sure the throttle/cruise control cables do not hold the throttle open. With the engine OFF, check to see that the accelerator pedal is free.

  10. Connect the throttle cable.
  11. Install the air intake tube.
  12. Connect the breather hose to the valve cover.
  13. Connect the IAT sensor connector.
  14. Connect the negative battery cable.
  15. Fill the cooling system.