I have somehow managed to activate the security on my 1996 Deville. I can open the doors but ignition not working. The only thing I did for the first time was change the wheels/tires from my 2003 Cadillac Deville to the 1996 at my home. Have not been able to start it since. Can anyone help?
You can try this procedure I listed below but you may have an ignition fault that is causing the no start. The information below is from the Alldata information website.
First, try to resynchronize the system by pressing the "Unlock" and "Lock" buttons together within range of the vehicle for approximately 7 seconds. There should be some feedback from the vehicle that the system has been synchronized (horn honks, locks cycle, lights flash, etc).
On 1996-97 Cadillac models (except Catera), and on the 1998 Catera, use the "Trunk" and "Lock" buttons to resynchronize. There will be no feedback from the system.
You have two crank sensors, a cam sensor, PCM (Power Control Module) and an ignition module as the main components of the ignition system. Any one of these components can cause the ignition not to fire.
The first step is to have someone scan the computer for any trouble codes; repair any code that may come up.
The system is complicated and you may need a qualified mechanic to repair the system.
Let us know how you make out with the information I gave you. If it doesn't help the get back to me and we can diagnosis the problem further.