Pontiac Montana SV6 2007 Owner's Manual page 156

Be sure that people and objects are clear
of the garage door or security device you are
programming. When programming a garage door,
it is advised to park outside of the garage.
156
If you do not know if your garage door opener is a
fixed code or rolling code device, open your
garage door opener's remote control battery cover.
Your garage door opener is a fixed code device
if there is a panel of switches. If not, your
garage door opener is a rolling code device.
Programming Universal Home
Remote — Fixed Code
Fixed Code garage door openers are used for
garage doors produced prior to 1996. Fixed code
uses the same coded signal every time, which
is manually programmed by setting DIP switches
for a unique personal code.