GMC 2007 Envoy - Manual (Page 101)

You can use your key to unlock your door from
the outside.
You can lock or unlock the door from the inside by
sliding the manual lever forward or rearward.
When the door is unlocked, you can see a red
area on the lever.
The manual lever on each door works only that
door’s lock.
Power Door Locks
The power door lock
switches are located on
the driver’s and front
passenger’s door
armrests.
Press the lock symbol to lock all of the doors.
To unlock the doors, press the other side of the
switch.
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