2010 Chevrolet Traverse Owner's Manual - Page 289

Driving and Operating 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 5 mph (8 km/h). 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 beeps are continuous. To be detected, objects must be at least 25.4 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. The system can be disabled through the Driver Information Center (DIC). See "Park Assist" under Vehicle Personalization (With DIC Buttons) on page 5‑40 for more information. 9-33 When the System Does Not Seem to Work Properly If the URPA system does not activate due to a temporary condition, the message PARK ASSIST OFF displays on the DIC when the shift lever is moved into R (Reverse). This may occur under the following conditions: . . . A tow bar is attached to the vehicle. The vehicle's bumper is damaged. Take the vehicle to your dealer/retailer to repair the system. Other conditions may affect system performance, such as vibrations from a jackhammer or the compression of air brakes on a very large truck. . . The driver disables the system. The ultrasonic sensors are not clean. Keep the vehicle's rear bumper free of mud, dirt, snow, ice and slush. For cleaning instructions, see Exterior Care on page 10‑86. A trailer was attached to the vehicle, or a bicycle or an object was hanging out of the liftgate during the last drive cycle. Once the attached object is removed, URPA will return to normal operation. If the system is still disabled, after driving forward at least 25 km/h (15 mph), take the vehicle to your dealer/retailer. .