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 WarningDome Lamps
The dome lamp controls are in the headliner.
(Dome Lamp Override): Press
to turn the lamps off, even when a door is open.
(Door): Press to turn the
lamps on automatically when a door is opened.
(On): Press to turn on the
dome lamps. ...
Exterior Lighting
The exterior lamp control is to the left of the steering column on the instrument
panel.
: Briefly turn to this position
to turn the automatic lamp control off or on again.
AUTO: Turns the headlamps on automatically at normal brightness, together with
the parking lamps, taillamps, license ...
Fuel Tank Filler Pipe Housing Replacement
Preliminary Procedure
Remove rear wheelhouse panel liner. Refer to Rear Wheelhouse Panel Liner
Replacement.
Remove fuel tank filler door. Refer to Fuel Tank Filler Door
Replacement.
Fuel Tank Filler Door Lock Actuator
Procedure
Disconnect electrical connector.
Fuel Tank ...