GMC 2007 Sierra 1500 Pickup Owner's Manual page 124

3. Press the door lock switch once. You will hear
either one or two chimes. The number of
chimes tells you which lock mode is currently
selected. Continue to press the door lock
switch until the number of chimes that
you hear matches the number of the mode
that you want. If you take longer than
30 seconds, the locks will automatically lock
and unlock and the horn will chirp twice
to indicate that you have left the program
mode. If this occurs, you can repeat the
procedure beginning with Step 1 to re-enter
the programming mode.
You can exit the program mode any time by
turning the ignition to RUN (the doors will
automatically lock and unlock and the horn will
chirp twice to indicate that you are leaving
the program mode). If the lock/unlock switches are
not pressed while in the programming mode,
the current automatic settings will not be modified.
See your dealer for more information.
124
Programmable Unlocking Feature
The following is the list of available programming
options:
Mode 1: Driver's door unlocks when the
transmission is shifted into PARK (P), for automatic
transmission vehicles only.
Mode 2: All doors unlock when the transmission
is shifted into PARK (P), for automatic
transmission vehicles only. This is the mode that
is pre-programmed in the factory for your
vehicle.
Mode 3: All doors unlock when the key is
removed from the ignition. This is the mode that is
pre-programmed in the factory for manual
transmission vehicles.