1998 GMC Sonoma Owner's Manual - Page 67

This vehicle has one double-sided key for the ignition and door locks. It will fit with either sideup. When anew vehicle is delivered, the dealer provides the owner with a pair of identical keys and a key codenumber. NOTICE: Your vehicle has a number of features that can help prevent theft. But you can have lot of a trouble gettinginto your vehicleif you ever lock your keys inside. You may even have to damage your vehicle to get in. be sure you So have extra keys. The key code number tells your dealer or a qualified locksmith how to make extra keys. Keep this number in a safeplace. If you lose your keys, you'll be able to have new ones made easily using this number. Your selling dealer shouldalso have this number. 2-3