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Eric, Automotive Repair Shop Manager
Category: Cadillac
Satisfied Customers: 31925
Experience:  20+ yrs. experience as repair shop manager and technician.
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how could you reset the computer in a 2002 cadillac deville

Resolved Question:

how could you reset the computer in a 2002 cadillac deville
Submitted: 7 years ago.
Category: Cadillac
Expert:  Eric replied 7 years ago.



Is this due to the same problem you have already asked about - the security light?

Customer: replied 7 years ago.
yeah when i go to crank it it just dont do anything. it dont say nothing like my theft system stopping me from cranking up.
Expert:  Eric replied 7 years ago.



Ok, what we are going to try is a re-learn procedure, but you will need your original master key for this, it cant be a duplicate.


When performing the 30-minute relearn procedure, all previously learned keys will be erased from the TDM memory. Additional keys may be learned after performing the relearn procedure.


  • With a master vehicle key, turn ON the ignition, with the engine OFF.
  • Observe the security indicator. After approximately 10 minutes, the telltale(security light) will turn OFF.
  • Turn OFF the ignition, and wait 5 seconds.
  • Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes.

    Important: The vehicle learns the key transponder information and/or passwords on the ignition switch transition from OFF to RUN. You must turn the ignition OFF before attempting to start the vehicle.

  • With a master vehicle key, start the vehicle. The vehicle has now learned the key transponder information and/or the ECM has now learned the fuel continue password.
  • If additional keys are required to be learned:
  • Adding Keys


    To initiate, this procedure requires that a learned master key be available.
    A total of 10 master keys or valet keys may be programmed to a single vehicle.
    This procedure adds keys only. The procedure does not erase previously learned keys.
    The keys to be learned must duplicate the mechanical cut of the current key.
    If more than one valet key is to be learned, immediately precede each valet key with a learned master key.


    1. With a previously learned master key, turn ON the ignition, with the engine OFF.
    2. Turn OFF the ignition and remove the key.
    3. Within 10 seconds insert the key to be learned. Turn ON the ignition with the engine OFF. The vehicle has now learned the new key.

    If, after having done this procedure the car still wont start, then a gm factory diagnostic scanner is absolutely required in order to help you as there is a problem within the security/antitheft system that is preventing key recognition. Not even an independent shop has the right type of scanner to help. Only a dealership can do this, as much as it pains me to say, as I am an independent and am not allowed to purchase one of their scanners.


    As you found out, disconnecting the battery doesnt "reset" the computer or erase any fault codes. while that would work on 1995 and older gm vehicles, it wont work on the ones built since 1996. Only a diagnostic scanner can do this.


    Eric and other Cadillac Specialists are ready to help you