GM 12589056
Throttle Body

To service the Throttle Body start with removing the air cleaner intake duct. Open the throttle valve to maximum to check for deposits in the bore of the Throttle Body and throttle valve plate. Clean Throttle Body bore and throat valve plate with clean shop towel and top engine cleaner (GM P/N 1052626) or like product; if required, use a parts cleaning brush to clean heavy deposits. Do not use an immersion cleaner or stronger solvent on assemblies that have the throttle position (TP) sensor, idle air control (IAC) valve and sealed throttle shaft bearings because these cleaners have the potential to harm the electric components and sensors as well as seals or o-rings. In addition, solvents can carry away non serviceable throttle shaft bearings' bearing grease. Avoid using a wirebrush/scrapper as well because these devices could damage Throttle Body parts; do not clean with solutions that contain the substances like methyl ethyl ketone, which is, however, unnecessary for this cleaning exercise. Lastly, load the air cleaner duct in place.

Begin Throttle Body service by taking out the air cleaner intake duct. A thorough throttle position check reveals deposits within both the Throttle Body bore and the throttle valve plate when the throttle valve is fully opened. You need to clean the Throttle Body bore and throttle valve plate using a shop towel together with top engine cleaner (GM P/N 1052626) or an equivalent cleaning product. Use a parts cleaning brush for heavy deposits when performing thorough cleaning. Weak solutions and immersion cleaners harm electric components, sensors and seals or o-rings when used with assemblies that contain the throttle position (TP) sensor, idle air control (IAC) valve, or sealed throttle shaft bearings. Non-serviceable throttle shaft bearings can suffer damage through solvent exposure which breaks down their grease protection. Throttle Body components may sustain damage from wire brushes or scrapers while cleaners with methyl ethyl ketone should be avoided because they cause component damage during Throttle Body cleaning. You should replace the air cleaner duct as your final step.

Remove the throttle body bolts and take out the throttle body along with the gasket.

Reinstall the wiring harness conduit, connect the throttle body electrical connector, and finally, reinstall the air cleaner intake duct.

Reinstall the wiring harness conduit and the throttle body electrical connector, then reattach the air cleaner intake duct.

Reconnect the throttle body coolant bypass hoses, the heater pipe nut, the IAC valve electrical connector, and the TP sensor electrical connector.

Clean the throttle body mounting surfaces of any gasket or seal material.

Reinstall the wiring harness conduit and the throttle body electrical connector, followed by the air cleaner intake duct.

Clean the throttle body mounting surfaces to remove any gasket or seal material, then install the throttle body with a NEW gasket and secure it with the throttle body bolts, tightening them to 10 N.m (89 lb in).

Install the throttle body and NEW gasket.

Reconnect the electrical connector to the throttle body assembly.

Deposits may accumulate on the back of the throttle plate.