DE10014188A1 - Operating motor vehicle lock system remotely controlled by coded signals using dialogue method involves desynchronizing alternating code when lock unit is locked by mechanical key - Google Patents

Abstract

The method involves desynchronizing the alternating code from a portable transmitter-receiver unit and a vehicle transmitter-receiver unit when the lock unit is locked using the mechanical key and resynchronizing the code when the lock unit is unlocked with the key or a mechanical ignition lock is operated with an associated mechanical key. Different codes can be used for locking and unlocking.

Description

The invention relates to a method for operating one in one Dialogue method by coded signals remotely controllable force Vehicle locking system, which is additionally mechanically controlled by a Key operated with a portable transceiver unit, a lock unit attached to the motor vehicle, a vehicle-side transmitter assigned to the lock unit Receiver unit and a control unit for controlling the Lock unit, the codes of the signals alternating codes represent.

Such a method is known from DE 43 08 899 C1.

Modern remote control systems use code systems that each actuation of the code transmitter, e.g. B. a radio transmitter, one new code, that is, transfer a change code. Will this If the code is recognized by the receiver, the desired reaction takes place, for example by locking the doors of a motor vehicle or unlocked. The last transmitted code loses its validity, d. H. unlike a fixed code system for no further action become. Such a change code system is therefore more secure than a fixed code system. Nevertheless, it can still be attacked by receiving the transmitted code at the receiver disturbed and at the same time the transmitted signal is recorded. An unauthorized person can thus obtain a valid code with which he can then gain access to the vehicle.

The present invention is based on the object To create methods of the type mentioned that a  Overcoming the change code system and thus an unauthorized one Access to one with an appropriate locking system equipped motor vehicle prevented or at least difficult.

This object is achieved in that Lock the lock unit using the mechanical key sels the change codes of portable transceiver and Vehicle-side transmitter-receiver unit desynchronized be and be synchronized again when the lock unit unlocked using the mechanical key or a mecha African ignition lock with an associated mechanical key is operated.

The solution according to the invention ensures that a Unauthorized person who operates the remote control system the authorized user to receive the transmitted code on Receiver interferes and simultaneously records the transmitted signal net, does not receive a code that matches the mechanical Locking the motor vehicle access to the vehicle would enable.

An advantageous embodiment of the invention The procedure is to lock the lock alternate codes are used than for the Unlock the lock unit. This will make security against unauthorized access to the motor vehicle elevated.

Another advantageous embodiment of the invention The procedure is for an unlock command another preparation of the basic change code was carried out is considered for a lock command. This also makes the Security against unauthorized access to the motor vehicle continues elevated.

The invention is explained in more detail below with reference to a drawing. The single figure shows a schematic representation of an example of the operation according to the invention of a motor vehicle locking system which can be remotely controlled by means of the coded signal. There is an electronic immobilizer in the motor vehicle 1 . To lock the vehicle 1 , the user actuates the locking button 2 of the remote control 3 assigned to the locking system of the motor vehicle. The remote control 3 generates a code that changes each time the remote control is operated and sends it to the vehicle 1 . If this code is recognized by a vehicle-side transceiver unit, the lock unit attached to motor vehicle 1 is locked.

However, if the receipt of the transmitted code by an unauthorized person who also intercepts the transmitted signal with a transmitter-receiver unit 4 is disturbed by a transmitter unit 5 arranged near the vehicle, the locking of the vehicle 1 remains off. The authorized user who recognizes this will try again to lock the vehicle 1 by means of his remote control 3 , but this is due to an analogous procedure of the one who gains unauthorized access to the vehicle by means of the transmitter / receiver unit 4 and the transmitter unit 5 which interferes with reception wants, or if necessary, is prevented again by a permanent disturbance. Ultimately, the authorized user will lock his vehicle by means of the mechanical key 6 combined with the remote control 3 and leave it in this state.

In a conventional motor vehicle locking system of the type mentioned at the outset, the person who has disrupted the reception of the transmitted code at the transmitter / receiver unit of the vehicle 1 and at the same time has recorded the transmitted signal by means of the transmitter / receiver unit 4 could use the recorded code in order to use it To provide access to the vehicle. He only needs to know where the corresponding bit information (status bits) are hidden in the recorded code sequence, which tell the vehicle-side locking system whether the unlock button 7 or the lock button 2 was pressed on the key.

In a motor vehicle locking system operated according to the invention, however, this procedure is unsuccessful, since when the lock unit is locked by means of the mechanical key 6, the change codes of the transmitter-receiver unit of the remote control 3 and the vehicle-side transmitter-receiver unit are desynchronized. A renewed synchronization of the change codes of the two mutually assigned transceiver units takes place according to the invention only when the lock unit is unlocked by means of the mechanical key 6 or a mechanical ignition lock in the vehicle is actuated with the mechanical key 6 . The code sequences already used between remote control 3 and vehicle 1 are compared via a bidirectional electromagnetic communication interface.

In contrast to conventional motor vehicle locking systems type mentioned in which for locking and the Unlocking and using the same change codes from a locking command very easily Unlocking command can be generated is at the The inventive method additionally provided that for Lock and unlock different change codes be used. Alternatively or additionally, can also by a different preparation of the basic change code for the unlocking or locking command are prevented, that a lock command into an unlock command is changed.

Claims (3)

1.Method for operating a motor vehicle locking system which is remotely controllable in a dialog method by coded signals and which can additionally be actuated mechanically by a key, with a portable transmitter / receiver unit, a lock unit attached to the motor vehicle, a vehicle-side transmitter / receiver unit assigned to the lock unit and one Control unit for controlling the lock unit, the codes of the signals representing change codes, characterized in that when the lock unit is locked by means of the mechanical key, the change codes of the portable transmitter-receiver unit and vehicle-side transmitter-receiver unit are desynchronized and resynchronized when the lock unit is activated by means of the mechanical key is unlocked or a mechanical ignition lock is actuated with an associated mechanical key. 2. The method according to claim 1, characterized in that for the Locking the lock unit uses other change codes be used for unlocking the lock unit. 3. The method according to claim 1 or 2, characterized in that for one Unlocking command another processing of the Basic change codes are performed as for one Lock command.