GMC 1997 Safari Owner's Manual page 81

Power Door Locks (If Equipped)
If your vehicle has power
door locks, press the power
door lock switch to lock or
unlock all the doors at once.
The power door lock switch will not lock or unlock the
rear hatch and Dutch doors. You must use the REAR
HATCH button. See "Rear Hatch and Dutch Doors
Release" in this section.
Every vehicle with power door locks has a pulse lock
system. A pulse lock system works like this:
If the sliding door is open and you press the power door
lock switch: the sliding door will not lock immediately.
After you close the door, the system comes on and, in
about five seconds, locks the sliding door.
All models have overriding door locks. When
a
door is
locked, the door handle will not work the latch. This
will help stop a door from being accidentally opened.
However, power door locks do not affect the operation
of the hatch.
Leaving Your Vehicle
If you are leaving the vehicle, take your keys, open your
door and set the locks from inside. Then get out and
close the door.
Keyless Entry System
If your vehicle has this option, you can lock and
unlock your doors or unlock your rear hatch from about
3 feet (1 m) up to 30 feet (9 m) away using the remote
keyless entry transmitter supplied with your vehicle.
Your Keyless Entry System operates on a radio
frequency subject
to
Federal Communications
Commission (FCC) Rules and with Industry and Science
Canada.
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference,
and (2) this device must accept any interference
received, including interference that may cause
undesired operation.