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 20 cm (8 in) off the ground and below liftgate level. Objects must also be within 2.5 m (8 ft) from the rear bumper. The distance objects can be detected may be less during warmer or humid weather.

    See also:

    New for 2010
    GM has dropped the long-running 6.0-liter V-8 engine from the Sierra lineup, leaving the powerful 6.2-liter V-8 for heavy towing needs. The rest of the Sierra's eight-cylinder lineup benefits from ...

    Global Positioning System (GPS)
    • Obstruction of the GPS can occur in a large city with tall buildings; in parking garages; around airports; in tunnels, underpasses, or parking garages; or in an area with very dense trees. If GPS ...

    Rear Towing (Rear Wheels Off the Ground)
    Two-Wheel-Drive Vehicles Use the following procedure to dolly tow a two-wheel-drive vehicle from the rear: 1. Attach the dolly to the tow vehicle following the dolly manufacturer's instructions. ...