2002 GMC Sierra Factory Alarm/Keyless Entry

well im sure the fac alarm did work, could it of been possible that you didnt hear it.. hitting the unlock button inside the vehicle will not turn off the factory security system. you can try this yourself, sit inside the vehicle, arm the fac system while your inside...wait for the factory security light to go out, it will stay on constant  i believe for 15 seconds. after that, manually unlock the vehicle with the switch or unlock the the latch manually and open the door. your alarm should start honking. otherwise, possibly when you last left your vehicle, if you didnt close the door all the way, whether driver side orpassender, or  left the hood open,,even if you hit lock on your fac remote and hear the lock s lock up. the system will not arm because a latch is not closed all the way. if all else fails..go back to the dealership and have em check it out.steve p.

Thanks for the info. I knew how to test the alarm, just didn't know if someone knew how to bypass this some way or not. Thanks for the reply!