GMC SIERRA 2002 Manual page 91

The following is a list of the available
programming options:
D
All doors lock/Only the driver's door unlocks:
Press the lock side of the power door lock switch on
the door panel once and then the unlock side once.
D
All doors lock/All doors unlock: Press the lock side
of the power door lock switch on the door panel
once, and then the unlock side twice.
D
All doors lock/None of the doors unlock: Press the
lock side of the power door lock switch on the door
panel once, and then the unlock side three times.
D
No doors lock/None of the doors unlock: Press the
lock side of the power door lock switch on the door
panel twice. This turns off the automatic lock feature.
For more information, see your dealer.
2-10
Lockout Prevention
To protect you from locking your key in the vehicle, this
feature stops the power door locks from locking when
the key is in the ignition and a door is open.
If the power lock switch is pressed when a door is open
and the key is in the ignition, all of the doors will lock
and then the driver's door will unlock.