Note: This information is only valid for anti-theft systems fitted by Mercedes-Benz as standard equipment.
Some models are equipped with burglar alarm systems as standard equipment. The system has switches on all doors (including the trunk lid and tailgate], hood, audio unit and ignition switch, as well as a tilt sensor that is sensitive to shock. If you open a door, trunk lid, hood, or turn on the ignition or radio while the alarm is on, or if the tilt sensor is triggered, the horns will sound and the headlights will flash. The system also has an immobilization function that disables the ignition system / starter until the system is turned off.
Protection is activated using a key in the front door lock, or in the trunk lid lock; on later models, the system is activated when the doors are closed using the central locking. The LED in the center of the center console starts flashing to indicate that the anti-theft system is on.
Note: Early models (release until September 1987) the protection system is activated only with the help of the main (rectangular) key. If a secondary is used (round) key, the door will close but the anti-theft system will not turn on.
If the alarm system fails, contact a Mercedes-Benz workshop. Using a special diagnostic tester, you can quickly identify a system malfunction.