Parental Control
The RSE system may have a Parental Control feature, depending on the radio. To enable Parental Control, press and hold the radio power button for more than two seconds to stop all system features such as: radio, video screen, RSA, DVD and/or CD.
While Parental Control is on, 
displays.
When the radio is turned back on, Parental Control is unlocked.
See also:
What Makes a Denali
The changes from a regular Acadia to a Denali are obvious from the outside,
and they make the Acadia Denali look more put together, as if it were sculpted
from one piece of metal rather than glued ...
Heated Mirrors
For vehicles with heated mirrors:
(Rear Window Defogger):
Press to heat the mirrors.
See “Rear Window Defogger” under Dual Automatic Climate Control System on page 8‑4 for more informati ...
Odometer
Press the trip odometer reset stem until ODOMETER displays. This display shows the distance the vehicle has been driven in either kilometers (km) or miles (mi). ...