1997 Cadillac Catera Owner's Manual - Page 76

Ignition Positions NOTICE: If your key seems stuck LOCK and you can't in turn it, be sure you are using the correct key; if so, isit all the way in? If it is, then turn the steering wheel leftand right while youturn the key hard. But turn the key only with your hand. Using a tool to force could break the key or the it ignition switch.If none of this works, then your vehicle needs service. With the key in the ignition switch, you can turn the switch tofour different positions. LOCK Before you put the key the ignition will in, be inthe LOCK position. This is the only position in which you can remove the key.This position locks the ignition, steering wheel and transmission. It's a theft-deterrent feature. Keep in mind that you may to turn the steering have wheel a little in order for the key to be removed or turned freely from the LOCK position -- this is normal. (0): 2-15