How the System Works
URPA comes on automatically when the shift lever is moved into R (Reverse). A single tone sounds to indicate the system is working.
URPA operates only at speeds less than 8 km/h (5 mph).
An obstacle is indicated by audible beeps. The interval between the beeps becomes shorter as the vehicle gets closer to the obstacle.
When the distance is less than 30 cm (12 in) the beeping is a continuous tone for five seconds.
To be detected, objects must be at least 25 cm (10 in) off the ground and below liftgate 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.
See also:
Ultrasonic Parking Assist
For vehicles with the Ultrasonic Rear Parking Assist (URPA) system, it assists
the driver with parking and avoiding objects while in R (Reverse). URPA operates
at speeds less than 8 km/h (5 mph), ...
Fuel
For diesel engine vehicles, see “Fuel for Diesel Engines” in the Duramax Diesel Supplement.
For Vehicles with gasoline engines, please read this. ...
New for 2011
The Sierra Hybrid gets GM's OnStar 9.0 telematics system that GM says
provides better voice recognition. GM also said they have worked to cut down on
the amount of wind noise occupants hear. ...





