compression ratio BUICK LUCERNE 2008 Owner's Manual

How the System Works
URPA comes on automatically when the shift lever is
moved into REVERSE (R). The rear display will then
briey illuminate to let you know the system is working.
URPA operates only at speeds less than 5 mph
(8 km/h). If you are above this speed, the red light on
the rear display will ash.
To be detected, objects must be at least 10 inches
(25.4 cm) off the ground and below trunk level. Objects
must also be within 8 feet (2.5 m) from your rear
bumper. This distance may be less during warmer or
humid weather.
A single beep will sound the rst time an object is
detected between 20 inches (0.5 m) and 8 feet (2.5 m)
away. Beeping will occur for three seconds when
you are closer than 1 foot (0.3 m) from the object.
The following describes what will occur with the URPA
display as you get closer to a detected object:
Description English Metric
amber light 8 ft 2.5 m
amber/amber lights 40 in 1.0 m
amber/amber/red lights 23 in 0.6 m
amber/amber/red lights
ashing and beep for
three seconds1 ft 0.3 mThe system can be disabled through the Driver
Information Center (DIC). See “Park Assist” underDIC
Operation and Displays on page 3-49for more
information.
When the System Does Not Seem to
Work Properly
The driver disables the system.
The parking brake pedal is depressed.
The ultrasonic sensors are not clean. Keep your
vehicle’s rear bumper free of mud, dirt, snow,
ice and slush. For cleaning instructions, see
Washing Your Vehicle on page 5-98.
A trailer was attached to your vehicle, or a bicycle
or an object was hanging out of your trunk during
your 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 your vehicle.
The vehicle’s bumper is damaged. Take the vehicle
to your dealer/retailer 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 15 mph (25 km/h), take your vehicle to your
dealer/retailer.
2-40