Throttle Body Assembly Removal and Replacement

Typical Throttle Body Assembly:

Throttle Body Removal:

CAUTION: The throttle bore and valve deposits may be cleaned on the vehicle, using carburetor cleaner and a parts cleaning brush. Do Not use a cleaner that contains Methyl Ethyl Ketone. It is an extremely strong solvent, and not necessary for this type of deposit.
^ The throttle body parts may be cleaned following disassembly, in a cold immersion type cleaner such as GM X-55 or equivalent.
^ The throttle position sensor (TPS) and idle air control (IAC) valve should not come in contact with solvent or cleaner, as they are electrical components and may be damaged.

REMOVAL:

1. Disconnect the negative battery cable.
2. Partially drain the radiator, to allow the coolant hoses to be removed from the throttle body.
3. Remove the air inlet duct.
4. Remove the IAC valve and TPS electrical connectors.
5. Remove the coolant hoses from the throttle body.
6. Disconnect the throttle, TV (transmission control), and cruise control cables.
7. Remove the throttle body retaining bolts.
8. Remove the throttle body assembly and gasket, discard gasket.
9. Clean the gasket sealing surface on the intake manifold.

Throttle Body Identification:

NOTE: An eight digit part identification number is stamped on the bottom of the throttle body casting next to the coolant cover. Refer to this number if servicing, or part replacement is required.

INSTALLATION:

1. Install a new flange gasket.
2. Position and hold the throttle body in place on the intake manifold.
3. Install the throttle body retaining bolts and tighten to 25.0 Nm (18 lb.ft).
4. Connect the throttle, TV (transmission control), and cruise control cables.
5. Attach the coolant hoses to the throttle body.
6. Connect the vacuum lines.
7. Connect the TPS and IAC valve electrical connectors.
8. Connect the air inlet duct.
9. Refill the radiator to replace lost coolant.
10. Connect the negative battery cable.


IDLE LEARN PROCEDURE: Any time the battery is disconnected, the programmed position of the IAC valve pintle is lost, and replaced with a default value. To return the IAC valve pintle to the correct position, perform the following procedure:

1. After restoring battery power, connect the Tech 1 "Scan" tool.
2. Select "IAC System," then select "Idle Learn" in the "Misc. Test" mode.
3. Proceed with idle learn as directed.
^ This procedure allows the ECM memory to be updated with the correct IAC valve pintle position, for the vehicle, and provide a stable idle speed.