Security (Mislock Warning): Description and operation (page 2 of 2)

Immobilisation System - General The function of the immobilisation system is to prevent unauthorised starting of the vehicle. The ECU operates in a secure interface which cannot be by-passed or copied. Re-mobilisation is achieved through a transponder in the vehicle key which is energised by a transponder coil surrounding the ignition switch when the ignition is turned to 'AUX' position I. When energised the transponder data is read by the immobilisation ECU which will confirm the validity of the start request.

Ignition Switch Transponder Coil

The transponder coil is located in a black plastic housing which is located around the ignition key barrel. The coil is connected by two wires to the immobilisation ECU.

The transponder coil passes electrical energy and data at a frequency of 125 kHz to a transponder in the vehicle key, up to a range of 20 mm (0.78 in) from the coil.

Key Transponder Each vehicle is supplied with two vehicle keys and two separate RF transmitters. The RF transmitters are used to lock and arm the vehicle, and for the tail door window drop function. The key head contains the transponder used by the immobilisation system.