2012 Buick LaCrosse Owner's Manual - Page 309

Driving and Operating To be detected, objects must be at least 20 cm (8 in) off the ground and below trunk level. Objects must also be within 2.5 m (8 ft) from the rear bumper. The distance at which objects can be detected may be less during warmer or humid weather. 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. 9-43 ice, and slush. For cleaning instructions, see Exterior Care on page 10‑98. . Turning the System On and Off The URPA system can be turned on and off using the park assist button located next to the shift lever. 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 ASSIST OFF: If the URPA system does not activate due to a temporary condition, this message displays on the DIC. This can occur under the following conditions: . . 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. An object was hanging out of the trunk during the last drive cycle. Once the object is removed, URPA will return to normal operation. 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. . The LED next to the park assist button lights up when the system is on and turns off when it has been disabled. The driver has disabled the system. The ultrasonic sensors are not clean. Keep the vehicle's rear bumper free of mud, dirt, snow, . .