GMC 2006 Sierra - Manual (Page 103)

Power Door Locks
If your vehicle has this
power door lock switch,
press the raised side of
the switch, with the lock
symbol, on either front
door to lock all the doors
at once.
Press the recessed side of the switch with the unlock
symbol, to unlock all the doors at once.
If your vehicle has this
power door lock switch,
press the bottom of the
switch on either front
door to lock all the doors
at once.
Press the top of the switch to unlock all the doors at once.
The power door locks will operate at any time even
when the ignition is off.
The power door locks will also automatically lock
when the vehicle is out of PARK (P), or for manual
transmission, when the vehicle reaches 8 mph (24 km/h).
Operating the power locks may interact with the
theft-deterrent system, if equipped. See Content
Theft-Deterrent on page 2-19.
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