For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

California Proposition 65 WarningCommunication Interface Module Bracket Replacement
Communication Interface Module Bracket Replacement
Callout
Component Name
Preliminary Procedure
Remove the instrument panel lower compartment. Refer to
Instrument Panel Lower Compartment Replacement
1
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Hood Insulator Replacement
Hood Insulator Replacement
Callout
Component Name
1
Hood Insulator Plastic Retainer (Qty:?€‰6)
2
Hood Insulator
Procedure
Ensure the 3 integral tabs are secured to the hood.
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Transmission Fluid Pump, Front Differential Carrier Baffle, and Front Differential
Ring Gear Removal (6T40/45)
Transmission Fluid Pump, Front Differential Carrier Baffle, and Front
Differential Ring Gear Removal
Callout
Component Name
1
Front Differential Carrier Baffle Bolts M6 x 25 (Qty: 2)
...