GMC 2003 Sierra - Manual (Page 106)

If fl doOT IS opened without [he key or Ihe reitiote
keyless entry iransmttter, the alami will go off* Your
vehicle’s headlamps will flash and Ihe horn will sound lor
about two min ules, then will turn off to save the
bstlery power
Romember the theit-deterrenl system won't actívale rf
you lock the doora with a hey or use the manual
door krek. It activates only
if
you use a power door loch
switch with the door open, or with the remote keyless
entry transmrtten You should also rememloer tha!
you Can start yOur vehida with the earned ignition key ll
the alarm has been set off.
Here's how to avoid setting off the alarm by accident:
• If you don’t want to achvate the theft-cíeteríent
sysferrr, the vehicle should be locked with the daor
key affeMhe doors are dosed.
• Always unlock a door with a hey, or use the remote
keyless entry iransmrtter. Unlocking a door any
other way win sot off the alarm tf Ihe sysleim
has been armed.
If you set off the alarm by accident, unlock any door with
the key. You can also lum off the alarm by pressing
UNLOCK on the remote keyless entry iransmitter or by
placing the key in the ignition and turning it lo START*
Testing the Alarm
The alarm can be tested by foflowing thesfl steps:
1. From inside ihe vehicle, lower (he driver’s window
and open the driver’s door.
2. Activate the syslem by locking Ihe doors with (he
power door lock swilch while the door is of>en, or
with the remóle keyless entry transmitter.
3. Get out of the vehicle, dose (he door and wart for
thq security light to go out.
A. Then reach in through the window, unlock the door
With Ihe manuaJ door lock and open the door. This
shoLild set off (he alarm.
If the alarm does not sound when it should but the
vehicle's headlamps flash, check lo see if ihe horn
works. The horn fusa rnay ba blown. To replace
Ihe fuse, see Fuses
and Circuit Breakers on paQe 5-1 tl.
IT the alarm does not sound or ihe vohicie's headlamps
do not flash, Ihe vahide should be serviced by an
authorized service center.