Vehicle Security; Anti-Theft Alarm System - GMC 2012 Sierra Denali Owner's Manual

2-10 Keys, Doors, and Windows
2. With the tailgate about halfway
open, lift the right edge of the
tailgate from the lower pivot.
On vehicles with the tailgate
assist feature, raise the tailgate
nearly all the way to the closed
position prior to removing the
left edge.
3. Move the tailgate to the right to
release the left edge.
Reverse this procedure to reinstall
the tailgate. Make sure the tailgate
is secure.

Vehicle Security

This vehicle has theft-deterrent
features; however, they do not make
it impossible to steal.

Anti-theft Alarm System

This vehicle may have a content
theft-deterrent alarm system.
This is the security light.
To arm the theft-deterrent system:
1. Open the door.
2. Lock the door with the Remote
Keyless Entry (RKE) transmitter.
The security light should flash.
If the delayed locking feature is
active, the alarm will not be
activated until all doors are
closed and the security light
goes off.
3. Close all doors. The security
light will stop flashing and go off
after approximately 30 seconds.
The system is armed when the
security light goes off.
If a locked driver door is opened
without using the RKE transmitter, a
10 second pre-alarm will occur. The
horn will chirp and the lights will
flash. If the key is not placed in the
ignition and turned to START or the
door is not unlocked by pressing
the unlock button on the RKE
transmitter during the 10 second
pre-alarm, the alarm will go off. The
vehicle's headlamps will flash and
the horn will sound for about
30 seconds, then will turn off to
save the battery power.