Central locking installation for a motor vehicle

A remote lock apparatus for a motor vehicle having at least one lock, comprising:

• a controller means mounted to the vehicle for receiving a control pulse and causing locking or unlocking of the lock;
• a receiver mounted to the vehicle;
• a plurality of transmitters, separate from the vehicle each transmitter having transmitting means for transmitting a code word and a transmitter recognition signal to said receiver;
• said receiver having means for sending said control pulse to said controller means for causing the locking or unlocking of the lock;
• each said transmitter having means for randomly selecting a unique transmitter recognition signal during an initialization procedure, and a transmitter memory in which said transmitter recognition signal is stored;
• each said transmitter having a means for creating a unique randomly modified formation law during the initialization procedure and means for generating a sequence of code words according to the randomly modified formation law, and means for transmitting said randomly modified formation law to said receiver to be stored in memory assigned to said transmitter recognition signal for the respective transmitter;
• said receiver having means for recognizing a transmitter recognition signal transmitted by said transmitting means, and means for calculating an expected code word based on the modified formation law assigned to the respective transmitter recognition signal, and means for comparing the expected code word with a code word transmitted by the transmitter from the sequence of code words, whereby a correct correlation therebetween results in said means for sending said control pulse to issue said control pulse to said controller means.

A method of initializing a central locking system comprising the steps of:

• given an authorized initialization, generating a new transmitter identifier by a random number generator, and storing this new transmitter identifier in a memory of the transmitter;
• transmitting the new transmitter identifier and a random word from the transmitter to the receiver, forming a group of code words defined by a mathematical formation low modified the random word;
• during the initialization, comparing the new transmitter identifier in the receiver to pre-existing transmitter identifiers already stored, and automatically storing the new transmitter identifier in a memory of the receiver when this new transmitter identifier has previously not been stored;
• displaying a successfully implemented initialization to the user by a display element;
• and
• generating the group code words also in the receiver by said mathematical formation law modified by the random word.