Ensure you have the original master key fob for the vehicle.
Sit inside the LeSabre and close all doors.
Insert the original master key fob into the ignition switch and turn it to the "ON" position. Do not start the engine.
Within 10 seconds, press and hold the "UNLOCK" button on the original key fob for at least 5 seconds.
Within 10 seconds of releasing the "UNLOCK" button, press and hold the "TRUNK" button on the original key fob for at least 5 seconds.
Turn off the ignition and remove the original key fob.
Within 30 seconds of performing step 5, press the "LOCK" and "UNLOCK" buttons simultaneously on the new key fob for at least 5 seconds.
Once the horn beeps, turn on the ignition and verify that the new key fob works.
Repeat steps 6 and 7 for any additional key fobs you want to program.
Note: If the new key fob is not working, you might need to have it reprogrammed by a professional or a qualified locksmith.
