Key and Remote Handset (Security)

Key and Remote Handset

Each keyblade has an external waveform. The waveform is coded and recorded in a BMW Group database, therefore replacement keys are only available from franchised dealers/suppliers.

The transponder contains a 128 byte EEPROM which is programmed with vehicle identification data which is checked by the immobilisation ECU before re-mobilisation is activated. The information programmed into the EEPROM cannot be overwritten.

Immobilisation ECU The immobilisation ECU is the central component in the immobilisation system and is located behind the fascia in a central position.

The EWS-3D ECU communicates with the CCU and is connected to the diagnostic socket enabling diagnostic procedures to be carried out.

There is no audible or visual indication to the driver of the condition of the immobilisation system.

The immobilisation ECU receives information from related systems on the vehicle and passes a coded signal to the ECM to allow starting if all starting parameters have been met. The information is decoded by the ECM which will allow the engine run if the information is correct. The information is on a rolling code system and both the ECU and the ECM will require synchronisation if either component is renewed.

Depending on engine fitment, three different ECM's can be used on the vehicle. Each ECM communicates with the immobilisation ECU using the same protocol .

The immobilisation ECU also protects the starter motor from inadvertent operation. The ECU receives an engine speed signal from the ECM via the instrument pack. When the engine speed exceeds a predetermined value, the ECU prevents operation of the starter motor via an integral starter disable relay.

Immobilisation ECU and Key Ordering Procedure

The immobilisation system is a highly secure system and to maintain security, the supply of spare/replacement keys and immobilisation ECU's is restricted to BMW Group dealers only. Keys can be disabled to prevent use of an unauthorised key using TestBook (immobilisation diagnostic).