2008 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 158

Convex Mirror Object Detection Systems Ultrasonic Rear Parking Assist (URPA) For vehicles with the Ultrasonic Rear Parking Assist (URPA) system, it operates at speeds less than 5 mph (8 km/h), and assists the driver with parking and avoiding objects while in R (Reverse). The sensors on the rear bumper are used to detect the distance to an object up to 8 feet (2.5 m) behind the vehicle, and at least 10 inches (25.4 cm) off the ground. {CAUTION: A convex mirror can make things (like other vehicles) look farther away than they really are. If you cut too sharply into the right lane, you could hit a vehicle on your right. Check your inside mirror or glance over your shoulder before changing lanes. The passenger's side mirror may have convex glass. A convex mirror's surface is curved so more can be seen from the driver's seat. Your vehicle may also have a turn signal indicator on the mirror. An arrow on the mirror will flash in the direction of the turn or lane change. 2-64