GMC Sierra 2500 HD2022 Owner's Manual page 40

Pull the tab to turn on the display. Push the
tab to turn it off. When off the mirror is
automatic dimming. Adjust the mirror for a
clear view of the area behind the vehicle
while the display is off.
Press to scroll through the adjustment
options.
Press and to adjust the settings using
the indicators on the mirror. The indicators
will remain visible for five seconds after the
last button activation, and the settings will
remain saved.
The adjustment options are:
Keys, Doors, and Windows
Brightness
Zoom
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