2003 GMC Sierra 1500 Pickup Owner's Manual - Page 144

Passenger Air Bag Indicator Your mirror may be equipped with a passenger air bag indicator on the mirror glass, just above the buttons. If you have this feature the mirror will display the word ON, or an airbag symbol in Canada, when the passenger air bag is engaged. For more information see Passenger Sensing System on page 1-74 Outside Camper-Type Mirrors Outside Manual Mirrors Adjust your outside mirrors so you can just see the side of your vehicle and have a clear view of objects behind you. The mirrors can be folded in to enter narrow areas. The use of hood-mounted air deflectors and add-on convex mirror attachments may adversely affect mirror performance. If your vehicle is equipped with camper-type mirrors, they can be adjusted so you can have a clear view of the objects behind you. Pull out the mirror head to extend it for better visibility when towing a trailer. 2-57