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:

Vehicle Care
California Proposition
65 WarningControl Solenoid Valve and Transmission Control Module Assembly Inspection Automatic Transmission Unit
Verify the conditions listed below do not exist. Carefully inspect the control solenoidvalve assembly connectors and pins-(1, 2, 4, 6) for the condition. Repair or replaceas necessary.DamageBent pinsDebrisBroken retaining tabContaminationVerify there is no metallic debris inside the connectors near ...