Whenever the ignition is switched on, the immobiliser first reads the personal code and then asks for the interchanging code. If both answers are accepted, the immobiliser will release the Digital Motor Electronics (DME) with another coded signal, without which the engine cannot be started, not even by short-circuiting it. This data is transmitted through an aerial in the steering wheel lock and is therefore wireless.
The same principle is applied on the key with integral remote control, which is also fitted with a maintenance-free battery which recharges automatically while driving. And should you ever lose your key, you can have it deactivated by your authorised BMW dealer and receive a replacement key without delay.
