Buick 2010 Lucerne Owner's Manual page 146

URPA operates only at speeds less than 8 km/h
(5 mph). If the vehicle is above this speed, the red light
on the rear display will flash.
To be detected, objects must be at least 25 cm (10 in)
off the ground and below trunk level. Objects must
also be within 2.5 m (8 ft) from the rear bumper. This
distance may be less during warmer or humid weather.
A single beep will sound the first time an object is
detected between 1 m (40 in) and 2.5 m (8 ft) away.
Beeping will occur continuously when the vehicle is at
0.6 m (23 in) or closer to an object.
The following describes what will occur with the URPA
display as the vehicle gets closer to a detected object:
Description
amber light
amber/amber lights
amber/amber/red lights and
continuous beeping for
five seconds
amber/amber/red lights
flashing and continuous
beeping for five seconds
The system can be disabled through the Driver
Information Center (DIC). See Park Assist under DIC
Operation and Displays on page 4 47 for more
information.
3-38
Metric English
2.5 m 8 ft
1.0 m 40 in
0.6 m 23 in
0.3 m 1 ft
When the System Does Not Seem to
Work Properly
If the URPA system will not activate due to a temporary
condition, the message PARK ASSIST OFF will be
displayed on the DIC and a red light will be shown on
the rear URPA display when the shift lever is moved
into R (Reverse). This occurs under the following
conditions:
The driver disables the system.
The ultrasonic sensors are not clean. Keep the
vehicle's rear bumper free of mud, dirt, snow, ice
and slush. For cleaning instructions, see Washing
Your Vehicle on page 6 104.
A trailer was attached to the vehicle, or a bicycle or
an object was hanging out of the trunk during the
last drive cycle, the red light may illuminate in the
rear display. Once the attached object is removed,
URPA will return to normal operation.
A tow bar is attached to the vehicle.
The vehicle's bumper is damaged. Take the vehicle
to your dealer to repair the system.
Other conditions may affect system performance,
such as vibrations from a jackhammer or the
compression of air brakes on a very large truck.
If the system is still disabled after driving forward at
least 25 km/h (15 mph), take the vehicle to your dealer.