Single lock — operating principle (BMW 5 Series E39)

The single lock only works if both front doors are closed. The single lock ensures simultaneous locking and, accordingly, unlocking of the doors, trunk and fuel filler flap. It can be activated from the outside by inserting the key into the door or trunk lock, as well as by remote radio control or from the passenger compartment by pressing a special button or by using the door safety catches.

When the single lock is activated from the outside, the anti-theft system is simultaneously activated, preventing the doors from being unlocked using the fuses or opening handles (or deactivated) security alarm.

In addition to the functions "Turn on interior light" and "Open trunk", all functions implemented by means of the radio remote control can be performed by turning the key in the lock.

In case of an accident, the single lock is automatically unlocked, but the doors locked with safety catches are unlocked. In addition, the hazard warning lights and interior lights are turned on.