GMC 2010 Sierra - Manual (Page 217)

5. After entering all of the switch positions, 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.
Using Universal Home Remote
Press and hold the appropriate button for at least half of
a second. The indicator light will come on while the
signal is being transmitted.
Reprogramming Universal Home
Remote Buttons
Any of the three buttons can be reprogrammed by
repeating the instructions.
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