Question about 1998 Cadillac DeVille

2 Answers

I need to know how to do a relearning process for the PCM to communicate the TDS on my 1998 Cadillac DeVille I recently replaced the computer and it won't start! I plugged my scanner to it and it only reads out P1631 theft deterrent system password incorrect. how can i make my alarm system communicate with my PCM so it can relearn

Posted by on


2 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 17 Answers

Okay the theft needs a reboot put the key in the drivers door lock on and off or lock to unlock 3 times, then within 30 seconds or sooner you must turn the ing. Switch on. If it don't pick it up you must have the dealer recode the unit

Posted on Apr 02, 2015

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has achieved Level 3.

  • Cadillac Master
  • 919 Answers

The last time I looked, the PCM has to be programmed by a dealer or authorized shop for the vehicle VIN number (the anti-theft and radio systems will already be programmed to only accept this number). If it is, then the anti-theft system has to be reset, also usually by a dealer with a programmer.

Posted on Apr 02, 2015


3 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

  • 21 Answers


u need the owners manual. it tells how to change the theft deterrent system.

Posted on Oct 07, 2009

  • 10 Answers

SOURCE: Theft deterent system in 1999 Cadillac deville not working properly

Try taking the hot cable of the batter, let the computer reset, wait 5m, then put it back on tighten it up.

Posted on Apr 05, 2013

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Where Is the serial data class 2 module located, in my 2001 Cadillac deville?

A class 2 serial data bus is a communication network between control modules on the vehicle ! It is not a single module . The PCM/ECM - engine computer , ABS - air bags , BCM or in the case of your Caddy three computers make up the BCM , DIM ,RIM and the IPM . Your best bet would be to take your vehicle to a qualified repair shop .

Dec 06, 2016 | 2001 Cadillac DeVille

1 Answer

Pcm po135 for 1998 deville


Oct 05, 2012 | 1998 Cadillac DeVille

1 Answer

After getting a new key for the egnition car will say car theft car may not restart

These keys have a transponder in them that communicates with the antitheft system. It has to be the correct key, equipped with the anti theft transponder (not just a copy made at Ace hardware) and the key must be relearned to the system.

Dec 03, 2011 | 1998 Cadillac DeVille

1 Answer

I have a 2001 Cadillac Deville. It has a b 3031 DTC code set we have done the 30 Minute relearn process 3 times and we cannot get the code to clear and There is no other codes set in the computer.

sorry i have absolutely no idea here ,only sugesstion i can perhaps make is to disconnect the battery and then join the ends together and leave overnight and see if you discharge the capacitors so the ECU loses its memory .

Nov 01, 2011 | 2001 Cadillac DeVille

1 Answer

It seems the battery in my 04 cadillac deville is dead. I know the battery is located under the rear seat. Can I remove it without adverse effects on the computer?

you can replace battery with out effects.first turn off radio.before removing negative battery cable.when you install new battery, when you start the engine let it idle until get operating temperature.the computer will have to relearn it memory while engine idling operating throttle a little see if engine hesitate. it will hesitate some, when you can accelerate with out hesitation,engine tps sensor has relearned it position.if idle speed stable engine dont run rough and stall out in drive your pcm has relearned itself where you can drive it.

Apr 03, 2011 | 2004 Cadillac Deville

1 Answer

My car didnt start so i took it to auto zone to get hook on the diagnostic machine it showed need a cam shaft and crank shaft sensor i got them replace and a week later the same problem car will not start...

Does the vehicle run at all with the new sensors?? If it does and experiences stalls or hard starts, read the following. When replacing cam or crank sensors, the vehicle's computer must go through a "RELEARN PROCESS". This can only be done at a authorized GM dealer, and usually costs $130+. I'm not sure if your vehicle has been properly diagnosed, but very rare does both crank and cam sensors fail simultaniously. This problem may be beyond what has been diagnosed, If the relearn process don't work, this issue needs to be re-diagnosed by another tech.

Dec 16, 2010 | 2001 Cadillac DeVille

2 Answers

Replaced my computer on my 1998 cadillac deville and now it's telling me I have an anti-theft problem and it won't start - now what

If done at a Cadillac dealer it would not be doing that now. The PCM will need to be flashed with the VIN number of your car to operate again. ANY TIME THE COMPUTER IS CHANGED THE VEHICLE IDENTIFICATION NUMBER NEEDS TO BE ENTERED INTO THE prom IN THE COMPUTER

Apr 01, 2010 | 1998 Cadillac DeVille

1 Answer

Where is the computer for a 1998 Cadillac Deville

start looking at the relays, computer should be the last thing you look at

Feb 06, 2010 | 1998 Cadillac DeVille

Not finding what you are looking for?
1998 Cadillac DeVille Logo

191 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cadillac Experts


Level 3 Expert

80417 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a Cadillac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides