2008 GMC Sierra 1500 Pickup Owner's Manual - Page 95

If a locked door is opened without using the RKE transmitter, a ten 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 ten second pre-alarm, the alarm will go off. Your vehicle's headlamps will flash and the horn will sound for about two minutes, then will turn off to save the battery power. The theft-deterrent system will not activate if the doors are locked with the vehicle's key or the manual door lock. It activates only if you use the power door lock switch with the door open or the RKE transmitter. You should also remember that you can start your vehicle with the correct ignition key if the alarm has been set off. To avoid setting off the alarm by accident: Testing the Alarm To test the alarm: 1. From inside the vehicle, lower the driver's window and open the driver's door. 2. Activate the system by locking the doors with the RKE transmitter. 3. Get out of the vehicle, close the door and wait for the security light to go out. 4. Then reach in through the window, unlock the door with the manual door lock and open the door. This should set off the alarm. If the alarm does not sound when it should but the headlamps flash, check to see if the horn works. The horn fuse may be blown. To replace the fuse, see Fuses and Circuit Breakers on page 5-108. If the alarm does not sound or the headlamps do not flash, see your dealer/retailer for service. • If you do not want to activate the theft-deterrent system, the vehicle should be locked with the door key after the doors are closed. • Always unlock a door with the RKE transmitter. Unlocking a door any other way will set off the alarm if the system has been armed. If you set off the alarm by accident, press unlock on the RKE transmitter or place the key in the ignition and turn it to START to turn it off. 2-19