Buick LaCrosse Owner's Manual page 319

WARNING
The URPA system does not
detect pedestrians, bicyclists,
animals, or any other objects
located below the bumper or that
are too close or too far from the
vehicle. To prevent injury, death,
or vehicle damage, even with
URPA, always check behind the
vehicle and check all mirrors
before backing.
How the System Works
URPA comes on automatically when
the shift lever is moved into
R (Reverse). A single tone sounds
to indicate the system is working.
URPA operates only at speeds less
than 8 km/h (5 mph).
An obstacle is indicated by audible
beeps. The interval between the
beeps becomes shorter as the
vehicle gets closer to the obstacle.
When the distance is less than
30 cm (12 in) the beeping is a
continuous tone for five seconds.
To be detected, objects must be at
least 20 cm (8 in) off the ground and
below trunk level. Objects must also
be within 2.5 m (8 ft) from the rear
bumper. The distance at which
objects can be detected may be
less during warmer or humid
weather.
Driving and Operating
Turning the System On and Off
The URPA system can be turned on
and off using the park assist button
located next to the shift lever.
The LED next to the park assist
button lights up when the system is
on and turns off when it has been
disabled.
When the system is off, PARK
ASSIST OFF displays on the Driver
Information Center (DIC). The
message disappears after a short
period of time.
URPA defaults to the on setting
each time the vehicle is started.
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