GMC Terrain 2018 Owner's Manual page 149

148 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.