2008 Buick LaCrosse Owner's Manual - Page 116

How the System Works URPA comes on automatically when the shift lever is moved into REVERSE (R). The rear display will then briefly illuminate to let you know the system is working. URPA operates only at speeds less than 3 mph (5 km/h). If you are above this speed, the red light on the rear display will flash. 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 5 feet (1.5 m) from your 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 20 inches (0.5 m) and 5 feet (1.5 m) away. Repeated beeping will occur when you are closer than 20 inches (0.5 m) from the object. The following describes what will occur with the URPA display as you get closer to a detected object: Description amber light amber/amber lights amber/amber/red lights/continuous beep amber/amber/red lights flashing and continuous beep English 5 ft 40 in 20 in 1 ft Metric 1.5 m 1.0 m 0.5 m 0.3 m When the System Does Not Seem to Work Properly • The ultrasonic sensors are not clean, a red URPA display light may illuminate when the vehicle is in REVERSE (R). Keep your rear bumper free of mud, dirt, snow, ice and slush. For cleaning instructions, see Washing Your Vehicle on page 5-102. 2-42