1996 Cadillac Deville PCM EXCHANGE

Tiny
CHAS MURPHY
  • 1996 CADILLAC DEVILLE

Transmission problem
1996 Cadillac Deville V8 Front Wheel Drive Automatic 11/006 miles

THE TRANSMISSION HAS BEEN CHANGED IN THIS CAR AND HAS THE WRONG GEAR RATIO. THE CARS PCM IS WANTING 3:11 RATIO AND THE TRANSMISSION HAS 3:71 RATIO. HAVE A 1997 PCM WITH THE THE NEEDED 3:71 RATIO IN IT BUT GET A THEIF ALARM, CAR WILL NO START. QUESTION WOULD HAVING THE 1997 PCM FLASHED TO GET PAST THE THEIF ALARM WORK? THEY BOTH HAVE 4.6 NORTH STAR. THE 1997 IS OUT OF A SLS.

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Tuesday, October 28th, 2008 AT 6:33 PM

17 Replies

Tiny
MASTERTECHTIM
  • MEMBER

Have you tried the relearn procedure. 1 fully charged battery.2 start car and leave car on, car starts then stalls and theft light flashes for ten minutes then goes out. 3 turn off the key then it should start.

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Tuesday, October 28th, 2008 AT 6:37 PM
Tiny
CHAS MURPHY
  • MEMBER

THE CAR WILL NOT START. IT HAS AN ANTI-THIEF ALARM. BY RELEARN PROCEDURE DO YOU MEAN LEAVE KEY ON FOR THIRTY MINUTES IN THE ON POSITION?

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Tuesday, October 28th, 2008 AT 6:50 PM
Tiny
MASTERTECHTIM
  • MEMBER

When you turn the key to run position does the theft light or the security light flash constantly? We are talking about a factory alarm and not a aftermarket alarm?

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Tuesday, October 28th, 2008 AT 6:56 PM
Tiny
CHAS MURPHY
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THE PUSH BRAKE TO SHIFT MESSAGE FOLLOWED BY THEIF ALARM CAR MAY NOT START THIS FACTORY MESSAGE BOARD AFTER WAITING IT WILL CARNK OVER BUT WILL NOT FIRE OR START.

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Tuesday, October 28th, 2008 AT 7:03 PM
Tiny
MASTERTECHTIM
  • MEMBER

Ok im not 100 percent sure but I dont think it can be reprogrammed with a used pcm, I think your pcm will need replacement and then reprogramming. I will pass this post along to some other mods and see if they can give you a more definitive answer

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Tuesday, October 28th, 2008 AT 7:06 PM
Tiny
CHAS MURPHY
  • MEMBER

The pcm for the 1996 will run the car but gives improper gear ratio. The pcm out of the 1997 sls will not allow me to get past the antitheif alarm. I did the 30 minute leaving the key on and the car would not start. A computor search gave me the compatabilty for my deville to the sls pcm that has the proper gear ratio in it. Just cant start the car

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Tuesday, October 28th, 2008 AT 7:19 PM
Tiny
MASTERTECHTIM
  • MEMBER

Ok im on mitchell right now and it appears the 96 has pass lock 2 system which uses a pellet in the key, can you verify that your ignition key has a pellet in it or not?

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Tuesday, October 28th, 2008 AT 7:34 PM
Tiny
CHAS MURPHY
  • MEMBER

If your refering to coded key yes it does.

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Tuesday, October 28th, 2008 AT 7:36 PM
Tiny
MASTERTECHTIM
  • MEMBER

The coded key with the pellet in it does not go through the pcm, its a seperated system and does not need programming from pcm.

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Tuesday, October 28th, 2008 AT 7:39 PM
Tiny
CHAS MURPHY
  • MEMBER

Guess I have to figure out what a pellet is?

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Tuesday, October 28th, 2008 AT 7:41 PM
Tiny
MASTERTECHTIM
  • MEMBER

It should be easy to see. Looking at the ignition key there will be a little pellet embedded in black plastic that has a resistance value. There are 12 possible resistance values. Basically if your looking at the ignition key and the door key, the ignition key should look different, right where the key enters the ignition cylinder should be the pellet. Is it possible for you to take a picture of key and upload it, then I can point it out to you or to make sure you have pass lock 2 system and we are on the same page?

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Tuesday, October 28th, 2008 AT 7:45 PM
Tiny
CHAS MURPHY
  • MEMBER

The key has a black sort of retangle with a sliver of metal in the middle of it approx 1/4 inch from the end of the key cut and below the plastic or rubber coating at the square top of the key blank

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Tuesday, October 28th, 2008 AT 7:56 PM
Tiny
MASTERTECHTIM
  • MEMBER

Exactly, thats pass lock 2. The no start is not from the theft system.

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Tuesday, October 28th, 2008 AT 8:01 PM
Tiny
CHAS MURPHY
  • MEMBER

This is my key


http://www.2carpros.com/forum/automotive_pictures/263069_PICT0019_1.jpg

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Tuesday, October 28th, 2008 AT 8:02 PM
Tiny
CHAS MURPHY
  • MEMBER

How do I get past the passlock 2 problem?

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Tuesday, October 28th, 2008 AT 8:12 PM
Tiny
MASTERTECHTIM
  • MEMBER

Yes that silver piece is the pellet. That system is all by itself and can be bypassed if need be by measuring resistance across the pellet and getting a resister to match it and then wire it across the 2 tiny white wires under the steering column in the orange sheeth. If the car ran before changing pcm then problem is going to be in the pcm. I would ask the dealer if the pcm can be programmed for the different gear ratio, they can give you a better and more definite answer.

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Tuesday, October 28th, 2008 AT 8:13 PM
Tiny
CHAS MURPHY
  • MEMBER

Thank you I will call dealer in am. I think I am in over my head here once again thanks

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Tuesday, October 28th, 2008 AT 8:18 PM

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