2007 GMC Yukon Owner's Manual - Page 207

How the System Works when Backing If the shift lever is in REVERSE (R), URPA detects objects close to the rear bumper. The first time an object is detected a single beep will sound. If an object is detected at a REVERSE (R) speed between 0 mph (0 km/h) and 5 mph (8 km/h), the following describes what will occur based on your distance to a detected object located behind the vehicle: • At distances between 40 inches (1 m) and 8 ft (2.5 m), a single amber light will come on. • At distances between 23 inches (0.6 m) and 40 inches (1 m), both amber lights will be on. • At distances between 12 inches (0.3 m) and 23 inches (0.6 m), all three lights (amber/ amber/red) will be on. • At distances less than 12 inches (0.3 m), a beeping sound will repeat for a short time and all three lights (amber/amber/red) will be on and flashing. When the System Does Not Seem to Work Properly If the URPA system will not activate due to a temporary condition, the message PARKING ASSIST OFF will be displayed on the DIC and a red light will be shown on the rear URPA display when the shift lever is moved into REVERSE (R). This occurs under the following conditions: • The driver disables the system. See DIC Operation and Displays (With DIC Buttons) on page 244 or DIC Operation and Displays (Without DIC Buttons) on page 251. • The parking brake pedal is depressed. • A trailer was attached to your vehicle, or a bicycle or an object was hanging out of your trunk during your last drive when you turned off the vehicle. If the attached objects are removed from your vehicle before the start of your next drive, the system will return to normal operation unless an object is detected when the vehicle is shifted into REVERSE (R). If this occurs, URPA assumes the object is still attached, so you will have to wait until the vehicle is driven forward above 15 mph (25 km/h) before URPA will return to normal operation. 207