Block Diagram
CAN abbreviations
The immobiliser function is integral with the CIM.
As soon as the ignition key is inserted in the ignition lock, the CIM communicates with the transponder in the ignition key via the integral transponder antenna, and evaluates the transponder signal.
If the ignition key is recognised as valid, the identities of the IPC, BCM, DDM, REC and PDM control units are then checked. If they are recognised as valid components, the enabling process is continued in communication with the engine control unit. If, in a particular vehicle, this control unit is incorrectly programmed or not present, start is not enabled by the CIM.
See also Chapter: Replacement of immobiliser system components
With ignition ON, the ECM requests start enabling from the CIM. If enabling fails, the ignition key must be removed from the ignition lock in order to obtain a new enabling via the transponder with renewed recognition.
The conversion of analogue to digital signals is performed by the CIM.
The immobiliser symbol in the instrument is actuated if the transponder is not recognised or the identification of the control units is not OK.
With this new immobiliser generation, the engine will not start and the starter is not actuated if an incorrect key is used.
The transponder is now a component of the circuit board in the ignition key.
Programming protection is effected via the security code, as previously.