2012 Chevrolet Tahoe Owner's Manual - Page 333

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 8 km/h (5 mph). An obstacle is indicated by audible beeps. The time between the beeps gets shorter as the vehicle approaches the obstacle. A continuous tone is heard when the distance is less than 30 cm (12 in). To be detected, objects must be at least 25 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. Press this button, located next to the radio, to disable URPA. The indicator light comes on and PARK ASSIST OFF displays on the Driver Information Center (DIC). See Object Detection System Messages on page 5‑41. 9-55 Turning the System On and Off PARK ASSIST OFF: This message occurs if the driver disables the system or if the vehicle is driven above 8 km/h (5 mph) in R (Reverse). PARK ASST BLOCKED SEE OWNERS MANUAL: This message can occur under the following conditions: . When the System Does Not Seem to Work Properly The following messages may be displayed on the DIC: SERVICE PARK ASSIST: this message occurs, take the vehicle to your dealer for repair. The ultrasonic sensors are not clean. Keep the rear bumper free of mud, dirt, snow, ice, slush, and frost. The message may not clear until frost or ice has melted all around and inside the sensor. A trailer is attached to the vehicle, or a bicycle or an object hanging out of the liftgate during the current or last drive cycle. URPA will return to normal operation after it is determined the object is removed. This could take a few drive cycles. A tow bar is attached to the vehicle. . .