General Motors is an automobile manufacturer that owns Chevrolet, Buick, GMC and Cadillac. Current automobiles use a theft-deterrent alarm system to prevent break-ins. The horn will sound while the headlights flash on and off. This will continue for several minutes unless you deactivate the alarm. After deactivating it, you can reset the alarm to ensure that your GM vehicle security system is set correctly.
Use your GM keyless remote to unlock the doors by pressing the "Unlock" button. This button looks like an opened lock. The other option is to unlock the doors with the GM key, and turn the car ignition on. These are the only two options for manually deactivating the alarm, and trying to unlock the doors in any other way will not work.
Exit the car and leave the door open. Press the lock switch from inside the car to lock the doors. Be sure all other doors, trunk, hood and lift gate are also closed. If anything else is open, the alarm will not be reset.
Close the door and wait for the security light to stop flashing from inside the car. Another option is to close the doors first, and then press the "Lock" button on the keyless remote. This will also pre-arm the theft-deterrent alarm system. If you do not open the doors or press the unlock button on the keyless remote for 10 seconds, the theft-system will go into armed stage.
