GMC 2012 Sierra Denali Owner's Manual page 165

To program another Rolling Code
device such as an additional garage
door opener, a security device,
or home automation device, repeat
Steps 1 through 5, choosing a
different function button in Step 3
than what was used for the garage
door opener.
If these instructions do not work,
the garage door opener is probably
a Fixed Code unit. Follow the
programming instructions that
follow for a Fixed Code garage
door opener.
Programming Universal Home
Remote Fixed Code
For questions or help programming
the Universal Home Remote
System, call 1-866-572-2728 or
go to www.learcar2u.com.
Most garage door openers sold
before 1996 are Fixed Code units.
Programming a garage door opener
involves time-sensitive actions, so
read the entire procedure before
starting. Otherwise, the device will
time out and the procedure will have
to be repeated.
Instruments and Controls
To program up to three devices:
1. To verify that the garage door
opener is a Fixed Code unit,
remove the battery cover on the
hand-held transmitter supplied
by the manufacturer of the
garage door opener motor.
If there is a row of dip switches
similar to the graphic above, the
garage door opener is a Fixed
Code unit. If you do not see a
row of dip switches, return
to the previous section for
Programming Universal Home
Remote
5-55
Rolling Code.