GMC Yukon Denalid Owner's Manual page 210

The red light in the URPA display will also be lit if
the vehicle is in REVERSE (R). If the vehicle
has a DIC, PARKING ASSIST OFF will display.
URPA automatically turns back on each time
the vehicle is started.
210
URPA can be turned off
by pressing the rear
park aid disable button
located below the
climate controls. The
indicator light on
the button will be lit to
indicate that URPA
is off.
How the System Works
When the shift lever is moved into REVERSE (R),
the rear display will briefly come on to let you
know the display is operating correctly. URPA
comes on automatically when the shift lever
is moved into REVERSE (R). The system also
does not work at a reverse speed greater than
5 mph (8 km/h). To remind you of this, the red light
on the rear display will flash.
The system can be disabled using the Driver
Information Center (DIC). See DIC Operation and
Displays (Using DIC Buttons) on page 245 or
DIC Operation and Displays (Using Trip Odometer
Reset Stem) on page 250.