Cadillac 2015 XTS Owner's Manual page 177

5-58 Instruments and Controls
Reprogramming a Single
Universal Remote System
Button
To reprogram any of the system
buttons:
1. Press and hold any one of the
buttons. Do not release the
button.
2. The indicator light will begin to
flash after 20 seconds. Without
releasing the button, proceed
with Step 1 under Programming
the Universal Remote System.