I dont know

Hello, The security lockout may be because the key has failed, the ignition module, or the security system control module has failed. Always, always, try to restart the vehicle with the same key, then try seconds later with the spare key. Hopefully, and in many cases, the key is bad, and needs to be replaced, and the replacement will need to be programmed. Any mobile locksmith can do it, but if they cannot communicate with your security system, you will likely need a new control unit. Let me know any questions you have, and here is a link if you would like shop recommendations: http://repairpal.com/cadillac-within-10-miles-of-eunice-louisiana-70535