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 WarningInstrument Panel Illumination Control
This feature controls the brightness of the instrument panel controls and infotainment
display screen. The thumbwheel is to the left of the steering column on the instrument
panel.
(Instrument Panel Brightness): Move
the thumbwheel up or down and hold, to brighten or dim the instrument pane ...
Driver or Passenger Seat Back Cushion Frame Replacement
Driver or Passenger Seat Back Cushion Frame Replacement
Callout
Component Name
Preliminary Procedures
Remove the driver or passenger seat. Refer to Driver or Passenger
Seat Removal and Installation
Remove the front seat c ...
Heating and Air Conditioning System Description and Operation
Engine Coolant
Engine coolant is the key element of the heating system. The engine thermostat
controls the normal engine operating coolant temperature. Coolant pumped out
of the engine enters the heater core through the inlet heater hose. The air
flowing through the HVAC module abs ...