1994 GMC Suburban Owner's Manual - Page 60

The oval-shaped key is for the doors and all other locks. \ \ When a new vehicle is delivered, the dealer removes the plugs from the keys, and gives them to the first owner. Each plug has a code on it that tells your dealer or a qualified locksmith how to make extra keys. Keep the plugs in a safe place. If you lose your keys, you'll be able to have new ones made easily using these plugs. NOTICE: Your vehicle has a number of new features that can help prevent theft. But you can have a lot of trouble getting into your vehicle if you ever lock your keys inside. You may even have to damage your vehicleto get in. So be sure you have extra keys. 2-4