1998 Cadillac Eldorado Owner's Manual - Page 73

The square key is for the ignition only. It has a resistor pellet which is part of the vehicle's PASS-Key@II system. When a new vehicle is delivered, the dealer removes the plug from the door key. The plug has a code on it that tells the dealer or a qualified locksmith how to make extra keys. Theignition key has a bar code tag attached to it rather than a knock out plug. Your dealer or qualified locksmith can make extra ignition keys by reading the bar code tag. There are 15 alternative ignition PASS-Key I1 blanks to help discourage theft. Keep the bar code tag and the door key plugs in a safe place. If you lose your keys, you will be able to have new ones made using the plug or bar code tag. The oval key is for the doors and ail other locks. I NOTICE: ~ ~~ Your vehicle has a number new features of that can help prevent theft. You can have a lot of trouble getting into your vehicle if you to ever lock your keys inside and you may have damage your vehicle to get in. Be sure you have extra keys. 2-3