2007 Chevrolet Avalanche Owner's Manual - Page 223

• The ultrasonic sensors are not kept clean. So, be sure to keep your vehicle's rear bumper free of mud, dirt, snow, ice, and slush. For cleaning instructions, see Washing Your Vehicle on page 550. If the DIC still displays the PARKING ASSIST OFF message after cleaning the bumper and driving forward at a speed of at least 15 mph (25 km/h), see your dealer. • Other conditions that may affect system performance include vibrations from a jackhammer or the compression of air brakes on a very large truck or other mechanical devices that interfere with URPA performance. • When URPA is disabled without driver action and the driver attempts to turn URPA back on by pressing the rear park aid button, the indicator light will flash for 3 seconds and then stay lit to indicate that URPA is off. As always, drivers should use care when backing up a vehicle. Always look behind you, being sure to check for other vehicles, obstructions and blind spots. For Driver Information Center messages related to URPA, see DIC Warnings and Messages on page 269. If the vehicle bumper is damaged, the URPA system may not work properly. Take the vehicle to your dealer to repair the system. 223