Cadillac Repair: Security System, lock cylinder, thin wire

Question
Vehicle is a 1998 Cad Deville.  Car will not start. Information panel says "theft system problem" car may not restart...
I am also seeing on the dash board that the transmission display of P R N D D2 D1 is blinking, I dont know if this means anything.
I talked to a dealer who seems to think that it may be the Ignition Lock cylinder that is the problem. All dealers seem very evasive in trying to help. All just want to have car towed in for testing... Any help is really apprecuated  

Answer
Hi,George

Yes it sounds like you need an ign lock cyl,the cyl has a small thin wire that reads the pellet on your key,this wire is thin and has a tendancy to break over time due to the lock cyl rotating,its a very common failure and will cause the security lamp to come on and a no start.if you were located in the Phoenix AZ area i would be more than happy to repair it for you.let me know were you are located and i can try to refer you to a dealership.Thanks

ED