6th Jul 2005, 19:36

I have the same problem if you find out the problem write back.

7th May 2006, 22:15

I have a 1999 Cadilliac Deville and it would say "Theft System Problem Car may not Restart". But it would always start. Now when I turn the ignition it makes a noise, but the car won't turn on.

11th Jan 2010, 10:49

There is a solution to starting your 96 Cadillac Deville.. The anti theft systems malfunction and keep the car from starting.. Get a diagram layout of your vehicles theft system and disconnect the entire theft system.. There is a power antenna wire located on your radio; disconnect that as well... The car should start fine.. you can always put another alarm in it.. Just go to your local pep boys or Walmart and purchase an alarm, open your hood, and there you go, the way an alarm is supposed to work.. not dysfunction the whole vehicle...

18th Feb 2010, 08:52

Theft system car, won't start every time. I hold the valet button in the glove box, and turn the key 3 times; on the fourth the car starts. Theft system problem; car may not start; light on, but this is how I get it to start, it works.

1st Mar 2010, 09:28

I have a 1996 Cadillac Deville. The day time running lamps work fine, but when I pull the switch to turn on regular headlights or switch the twilight sensor to turn on the headlights, they will not come on, and DRL turn off. Tail lights, brake lights and signals work fine, but REGULAR headlights will not come on, any ideas???

19th Oct 2010, 20:12

I changed the crank sensor, and ignition module, but I still have to try 2 or 3 times before it cranks; other times it will just turn over... I noticed "service ignition system" message populated. Any advice?

15th Apr 2011, 12:48

I have a 96 Cadillac Sedan DeVille. I've got a problem with my tail lights. When I turn the lights on, my headlights turn on and so do my taillights, but when I push the brakes, my taillights turn off. And my parking lights don't turn on either.. does any one have this problem or know how to fix it?? Email @ dj_mexican713@yahoo.com

3rd Jul 2015, 13:18

You probably have crossed wires. Run your wires and see if any are crossed.

17th Dec 2015, 17:52

Hi there, so how do I disconnect my anti theft system on my Cadillac DeVille 96? It won't start. I put a resistor on there under the dash, and it still won't work. How can I just take the system off? I don't care about the alarm.

21st Dec 2015, 12:42

I have a newer GM. I stopped using the key fob. Turned the alarm off with my remote. And now don't use it. Now simply lock and unlock the driver's door by the key. I start the car with the key, which has a chip in it anyway. My alarm isn't an issue, as is the factory fuel shutoff. I have had key fobs that didn't work due to bad batteries over time. Then you have to reprogram them through the dash or the car will not start. Some of the stuff on modern cars is a pain. Another waste of money is TPMs; the batteries go and a wheel has to be dismounted and a new TPM needs installed at around 100 each. And then all the O2 sensors etc today. I liked the old alarms in cars that used a separate key in the fender. Aftermarket, run straight off the battery. My 2 cents.