Cadillac 2009 STS-V - Manual (Page 115)

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 3 mph
(5 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 trunk level. Objects
must also be within 5 feet (1.5 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 20 inches (0.5 m) and 5 feet (1.5 m)
away. Beeping will occur when the vehicle is closer
than 20 inches (0.5 m) from the object.
The following describes what will occur with the URPA
display as the vehicle gets closer to a detected object:
Description English Metric
amber light 5 ft 1.5 m
amber/amber lights 40 in 1.0 m
amber/amber/red
lights/continuous beep
20 in 0.5 m
amber/amber/red lights
flashing and
continuous beep
1 ft 0.3 m
2-43