The system of an immobilizer consists of a passive priyemootvetchik (for a mutual identification), the key of the car mounted in a head, and the antenna SMARTRA block (SMARt TRansponder Antenna).
The SMARTRA block includes the built-in inductive aerial and the electronic schemes connected to the switch of ignition. The SMARTRA block is connected to the control unit the engine the special communication line.
Such way of management of the SMARTRA block is most expedient, as start-up of the engine the control unit operates the engine.
Principle of action of system
The system of an immobilizer includes the control unit the engine, the SMARTRA block and the priyemootvetchik which has been built in the ignition key.
The control unit the engine carries out an ignition key identification by means of the special coding algorithm operating in parallel in a priyemootvetchik and the control unit with the engine. Start-up of the engine is possible only at coincidence of results of action of algorithm. In memory of the control unit the engine stores data of all priyemootvetchik attached to the car.
The control unit by the engine and the SMARTRA block are reported among themselves on the special communication line. During action of this communication between the control unit the engine and SMARTRA the control unit line "K" the engine for other types of communication cannot be used, the control unit the engine establishes connection on the line "K" either with the SMARTRA block, or with other devices (for example, with the verifying device at maintenance) by turning on of the multiplexer and start-up of special procedures of communication. The multiplexer — a part of hardware of the control unit the engine. The SMARTRA block carries out communication through the priyemootvetchik which has been built in the ignition key. Communication is established on a radio frequency of 125 kHz. The SMARTRA block is placed on the ignition switch near a frame send-receive radio antenna. The radio-frequency signal accepted by the frame aerial will be transformed by the SMARTRA block in
messages for serial communication, and arriving from the control unit will be transformed by the engine of the message to the radio-frequency signal transferred through the aerial to a priyemootvetchik.
The SMARTRA block does not carry out an identification of a priyemootvetchik or calculation of algorithm of coding. It represents the advanced interface which will transform a data flow received on a radio frequency from a priyemootvetchik to sequence of the messages issued on the control unit by the engine, and on the contrary.
Priyemootvetchik — the Hitag 2 type with advanced algorithm of coding. When programming key special data of the car which register it are entered into a priyemootvetchik
memory. Record procedure disposable therefore it is impossible to change contents of memory of a priyemootvetchik. Data are entered in the form of the chain in length of 9 bytes made at manufacturer. Contents of memory of a priyemootvetchik share on two chains which carry the names "opoznavatel" and «the key password».
After that programming memory of a priyemootvetchik is blocked and its contents become impossible to consider or change. Priyemootvetchik passes from a condition "pure" "programmed" to a condition.
Besides, each priyemootvetchik is allocated with own identification number IDE in length 32 bits. The numbers IDE of priyemootvetchik are unique (do not repeat). The number IDE is entered at manufacturer and can be read out only.
Opoznavatel and the password of a key are not transferred from the control unit by the engine to a priyemootvetchik or back. Results of action of algorithm of coding are transferred only. By result of coding it is almost impossible to calculate special data of the car.
For coding of keys or other purposes the control unit the engine incorporates to the verifying device as which the factory tester used at Hyundai service stations can serve. Communication is carried out according to the protocol of the line "K" of the control unit by the engine.