Cadillac Repair: 99 Cadillac DeVille Security/Starting, cadillac dealer, cadillac deville

Question
My battery was disconnected to clean the posts.After reconnecting it, the engine wil not restart. Initially it tried to start but acted like fuel shut off, then it just cranks. Then message "Possible theft security" "car maynot restart". I called Cadillac's Hotline, they said to turn key off for 10 minutes, then to on position for 10 minutes, then off again, then try to start. I have done this repeatedly to no avail. I called back and they said I have to haul it in to the Cadillac dealer to get it reprogrammed to recognize my keys. I called the Cadillac dealer who informed me this will happen anytime I disconnect the battery. Iknow this is malarky as I have disconnected the battery numerous times in the last 6 years. What do I need to do? Thanks, Richard

Answer
Hi,Richard

Ive never seen a Cadillac go into theft enable by disconnecting the battery,usually the logic or the programed key is stored in the theft deterant module unless the module itself failed or its been replaced,first lets attempt to reset the modules:
 First disconnect both battery cables,short both positive and negative cable together without connected to the battery for at least 10 seconds.then reconnect,see if vehicle starts,if not do the following:
Clean the key,it has a black pellet in it,clean that,or attempt another key if you have one,and see if it starts,if it still fails to start then you have a failed ign lock cylinder,the lock cyl has a resistor with a very fine wire that leads to the Body Control module and theft deterent,that fine wire has a tendancy to break causing not data to be recieved to the module,you can attempt to start if you wiggle the key in the lock cyl while starting,if it just stays in theft mode then the only way to make it respond again is by changing the ignition lock cylinder.if you need more help let me know.Thanks


ED