2013 Chevrolet Silverado 3500 HD Crew Cab Owner Manual - Page 331

Driving and Operating the rear bumper. This distance may be less during warmer or humid weather. Notice: If you use URPA while the tailgate is lowered, it may not detect an object behind your vehicle, and you might back into the object and damage your vehicle. Always verify the tailgate is closed when using URPA or turn off URPA when driving with the tailgate lowered. . 9-63 Turning the System On and Off The URPA system can be turned on and off using the rear park aid disable button located next to the radio. The park assist sensors are covered by frost or ice. Frost or ice can form around and behind the sensors and may not always be seen; this can occur after washing the vehicle in cold weather. The message may not clear until the frost or ice has melted. A trailer was attached to the vehicle, or an object was hanging out of the tailgate during the last drive cycle. Once the object is removed and the tailgate is raised, URPA will return to normal operation. A tow bar is attached to the vehicle. The bumper is damaged. Take the vehicle to your dealer to repair the system. Other conditions, such as vibrations from a jackhammer or the compression of air brakes on a very large truck, are affecting system performance. When the System Does Not Seem to Work Properly The following messages may be displayed on the DIC: SERVICE PARK ASSIST: If this message occurs, take the vehicle to your dealer to repair the system. PARK ASST BLOCKED SEE OWNERS MANUAL: This message can occur under the following conditions: . . The indicator light comes on when the system is disabled and turns off when the system is on. When the system is off, PARK ASSIST OFF displays on the Driver Information Center (DIC). The message disappears after a short period of time. URPA defaults to the on setting each time the vehicle is started. . . 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 10‑93. .