1996 GMC Sonoma Owner's Manual - Page 50

This vehicle has one double-sided key for the ignition and door locks. It will fit with either side up. The bar-coded tag has a code on it that tells your dealer or a qualified locksmith how to make extra keys. Keep this tag in a safe place. If you lose your keys, you'll be able to have new ones made easily using this tag. NOTICE: Your vehicle hasa number of features that can help prevent theft. But you can have a lot of trouble getting into your vehicleif you ever to lock your keys inside.You may even have damage your vehicle get in. So be sure you to have extra keys. When a new vehicle is delivered, the dealer provides the owner with a pair of identical keys and a bar-coded tag. 2-2