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Tim Mohr
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Cadillac Deville DTS: How can the ignition be reprogrammed

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How can the ignition be reprogrammed after cylinder replacement?

Hello. My name is XXXXX XXXXX I will be assisting you today.


Do you have a scan tool?


What have you tried so far?


Customer: replied 3 years ago.
Replaced cylinder and need to reprogram . Can you recommend a affordable scantily if it will work

Actually William there is likely a way to do it without (an expensive) scan tool. It takes about 30 minutes and you will want to keep a charger, (or jumper cables) on it to keep the battery from dying.

30-Minute Relearn Procedure
Use this procedure after replacing the following components:

  • The passkey III (PK3) keys
  • The theft deterrent control module
  • The PCM, see important above
  1. With a master passkey III key (Black), turn ON the ignition, with the engine OFF.

IMPORTANT: This procedure is not available on vehicles equipped with option code (Z49 or BAE).
If replacing a theft deterrent control module with an GM SPO Replacement Part, perform the procedure to setup a new theft deterrent control module prior to the 30-minute relearn procedure.

  1. Observe the Security telltale, after approximately 10 minutes the telltale will turn off.
  2. Turn OFF the ignition, and wait 5 seconds .
  3. Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes .
  4. With a master passkey III key, start the vehicle. The vehicle has now learned the key transponder information and the PCM has now learned the fuel continue password.
IMPORTANT: The vehicle learns the key transponder information and/or passwords on the ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.


Let me know how that does, thanks


Customer: replied 3 years ago.
Hi Jerry, after 20mins telltale has not gone out. What is meant by master key. I am using key that came with new aftermarket cylinder.

The master key is black, (not gray like the valet key) and 20 minutes is too long, the light should have gone out. What was the original problem?
Customer: replied 3 years ago.
Key not going into cylinder
Did you just replace the cylinder and key?
Did you have to drill it out?


Customer: replied 3 years ago.
Key not going into cylinder

Just removed old cylinder like any GM and replaced with new cylinder and key.
Not sure what might be going on in there, (the lock cylinder or passkey sensor)

I will opt out and open it back up. Please DON’T REPLY to this post as that will lock the question back to me, also DON’T RATE THE ANSWER yet, someone should be along shortly, I’m sure, thanks and sorry I wasn’t able to help with it.


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Customer: replied 3 years ago.
Yes, please continue to search. My current problem is still the same. Ignition cylinder was bad,replaced with aftermarket part, engine starts but shuts down in 5 seconds. Tried previous experts procedure did not get any response from telltale. Cylinder was changed per prop procedures.
Thank you for your continued patience. We will continue the search for a professional for you.
Hi, my name is XXXXX XXXXX the key cylinder does not come with a pass key III key, it just comes with a key cut the proper cut for the cylinder, you will need a blank passkey III key, then take the key that came with the cylinder to a locksmith and have it cut, then use the new pass key with the above procedure, to program the key,Tim
Category: Cadillac
Satisfied Customers: 15708
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Customer: replied 3 years ago.
That is a good resolution. Will I have to recode new cut key as per procedures?

Yes, once the new key is cut, then use the above procedure to program it,Tim