2009 Chevrolet Suburban Owner's Manual - Page 163

How the System Works URPA comes on automatically when the shift lever is moved into R (Reverse). The rear display briefly illuminates to indicate the system is working. URPA operates only at speeds less than 5 mph (8 km/h). If the vehicle is 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 liftgate level. Objects must also be within 8 feet (2.5 m) 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 40 inches (1 m) and 8 feet (2.5 m) away. Beeping will occur continuously when the vehicle is at 23 inches (0.6 m) 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 English 8 ft 40 in 23 in 1 ft Metric 2.5 m 1.0 m 0.6 m 0.3 m The system can be disabled by pressing the rear park aid disable button located next to the radio. The indicator light will come on and PARK ASSIST OFF displays on the Driver Information Center (DIC) to indicate that URPA is off, see DIC Warnings and Messages on page 3-64 for information about clearing the message. 2-57