GMC 2012 Sierra Owner's Manual page 202

5-64 Instruments and Controls
A. Left Button (Up, +, or On)
B. Middle Button (Middle, 0,
or Neutral)
C. Right Button (Down, ,
or Off)
4. The indicator lights will blink
slowly. Enter each switch setting
from Step 2 into your vehicle's
Universal Home Remote. You
will have two and one-half
minutes to complete Step 4. Now
press one button on the
Universal Home Remote for
each switch setting as follows:
If you wrote Left, press
the left button (A) in the
vehicle.
If you wrote Right, press
the right button (C) in the
vehicle.
If you wrote Middle, press
the middle button (B) in the
vehicle.
5. After entering all of the switch
positions, once again firmly
press and release all three
buttons at the same time. The
indicator lights will turn on.
6. Press and hold the button that
will be used to control the
garage door until the garage
door moves. The indicator light
above the selected button
should slowly blink. This button
may need to be held for up to
55 seconds.
7. Immediately release the button
when the garage door moves.
The indicator light will blink
rapidly until programming is
complete.
8. Press and release the same
button again. The garage door
should move, confirming that
programming is successful and
complete.
To program another Fixed Code
device such as an additional garage
door opener, a security device,
or home automation device, repeat
Steps 1-8, choosing a different
button in Step 6 than what was used
for the garage door opener.