Antitheft apparatus for automotive vehicle and method of registering ID No. therein

An antitheft apparatus for an automotive vehicle, comprising:

• a transponder provided in an ignition key, for storing an ID number of its own ignition key therein;
• a transmit/receive unit provided in an ignition key cylinder, for transmitting a transmit signal to said transponder to receive the ID number, and for receiving a signal of the ID number of the ignition key inserted into the ignition key cylinder;
• and
• an immobilizer unit for, in antitheft mode, collating the received ID number of the ignition key with a plurality of ID numbers already stored therein and outputting an engine start enable signal when the received ID number matches one of the stored ID numbers but an engine start disable signal when does not match and for, in ID number register mode, registering the received ID number therein;
• said immobilizer unit further comprising means for releasing the ID number register mode into the antitheft mode automatically when the received ID number of the ignition key inserted into the ignition key cylinder matches any one of the plurality ID numbers already stored therein.

A method of registering an ID number of an ignition key in an antitheft apparatus, comprising the steps of:

• checking whether a first ignition key is inserted into an ignition key cylinder and further rotated to an IGN ON position;
• if the first ignition key is inserted into the ignition key cylinder and further rotated to the IGN ON position, transmitting a transmit signal to a transponder of the first ignition key inserted into the ignition key cylinder to receive a first ID number of the first ignition key;
• registering the received first ID number in a memory as the first ID number;
• checking whether a second ignition key is set to the IGN ON position;
• if the second ignition key is set to the IGN ON position, transmitting the transmit signal to a second transponder of the second ignition key inserted into the ignition key cylinder to receive a second ID number of the second ignition key;
• checking whether the received second ID number is the same as the first ID number;
• if the received second ID number is the same as the first ID number, releasing an ID number registered mode;
• if the received second ID number is not the same as the first ID number, storing the second ID number in the memory as the second ID number;
• checking whether a maximum number of ID numbers have been registered;
• if the maximum number of ID numbers have not been registered, repeating the ID number register processing;
• and
• if the maximum number of ID numbers have been registered, releasing the ID number register mode.

A method of registering an ID number of an ignition key in an antitheft apparatus, comprising the steps of:

• checking whether a first ignition key is inserted into an ignition key cylinder and further rotated to an IGN ON position;
• if the first ignition key is inserted into the ignition key cylinder and further rotated to the IGN ON position, transmitting a transmit signal to a transponder of the first ignition key inserted into the ignition key cylinder to receive a first ID number of the first ignition key;
• registering the received first ID number in a memory as the first ID number;
• checking whether a second ignition key is set to the IGN ON position;
• if the second ignition key is set to the IGN ON position, transmitting the transmit signal to a second transponder of the second ignition key inserted into the ignition key cylinder to receive a second ID number of the second ignition key;
• checking whether the received second ID number is the same as one of ID numbers already stored;
• if the received second ID number is the same as one of ID numbers already stored, releasing an ID number register mode;
• if the received second ID number is not the same as any of ID numbers already stored, storing the second ID number in the memory as the second ID number;
• checking whether maximum ID numbers have been registered;
• if the maximum ID numbers have not been registered, repeating the ID number register processing;
• and
• if the maximum ID numbers have been registered, releasing the ID number register mode.

An antitheft system for an automotive vehicle having an ignition switch and an engine comprising:

• a vehicle ignition key having a transponder for storing a key security code and transmitting a coded signal representing said key security code responsive to a request signal;
• a transceiver operatively connected to said vehicle ignition switch for transmitting said request signal and for receiving said coded signal;
• and
• a vehicle immobilizer, operatively connected to said transceiver and selectively operable in a registration mode for storing said key security code as a registered security code responsive to receipt of said coded signal and in an antitheft mode for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal if said coded signal corresponds to said registered security code;
• wherein, with said vehicle immobilizer remaining in the registration mode after storing of the key security code, said vehicle immobilizer is adapted to automatically switch from said registration mode to said antitheft mode responsive to said transceiver receiving said coded signal again and thereby twice in succession.

An antitheft system for an automotive vehicle configured to store a plurality of registered security codes having an ignition switch and an engine comprising:

• a vehicle ignition key having a transponder for storing a key security code and transmitting a coded signal representing said key security code responsive to a request signal;
• a transceiver operatively connected to said vehicle ignition switch for transmitting said request signal and for receiving said coded signal;
• and
• a vehicle immobilizer, operatively connected to said transceiver and selectively operable in a registration mode for storing said key security code as a registered security code responsive to receipt of said coded signal and in an antitheft mode for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal only if said coded signal corresponds to said registered security code;
• wherein said vehicle immobilizer is adapted to automatically switch from said registration mode to said antitheft mode responsive to said transceiver receiving said coded signal if said key security code has been previously stored as said registered security code.

An antitheft system for an automotive vehicle having an ignition switch and an engine comprising:

• a vehicle ignition key having a transponder for storing a key security code and transmitting a coded signal representing said key security code responsive to a request signal;
• a transceiver operatively connected to said vehicle ignition switch for transmitting said request signal and for receiving said coded signal;
• and
• a vehicle immobilizer, operatively connected to said transceiver, for storing a plurality of registered security codes up to a maximum number of registered security codes, and selectively operable in a registration mode for storing said key security code as one of said plurality of registered security codes responsive to receipt of said coded signal and in an antitheft mode for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal if said coded signal corresponds to one of said plurality of registered security codes;
• wherein said vehicle immobilizer is further adapted to automatically switch from said registration mode to said antitheft mode responsive to storage of said key security code as one of said plurality of registered security codes if a count of said plurality of registered security codes stored thereby equals said maximum number of registered security codes.

A method of operating an antitheft system for an automotive vehicle having an ignition switch and an engine comprising the steps of:

• storing a number of registered security codes up to a maximum number of registered security codes;
• receiving a coded signal representing a key security code corresponding to a vehicle ignition key;
• and
• automatically switching from a registration mode, for storing said key security code as one of said number of registered security codes, responsive to receipt of said coded signal, to an antitheft mode, for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal and said coded signal corresponding to one of said number of registered security codes, if a count of said number of registered security codes stored thereby equals said maximum number of registered security codes which can be stored.

An anti-theft system for an automotive vehicle having an ignition switch, operable with an ignition key, and an engine comprising:

• a receiver operatively connected to said vehicle ignition switch for receiving a coded signal representing a key security code from a transponder of said vehicle ignition key;
• and
• a vehicle immobilizer operatively connected to said receiver and selectively operable in a registration mode for registering said key security code responsive to receipt of said coded signal and in an anti-theft mode for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal and said coded signal corresponding to a registered security code;
• wherein, with the vehicle immobilizer remaining in the registration mode after registering the key security code, said vehicle immobilizer is adapted to automatically switch from said registration mode to said anti-theft mode responsive to said receiver receiving said coded signal again and thereby twice in succession.

An anti-theft system for an automotive vehicle having an ignition switch, operable with an ignition key, and an engine comprising:

• a receiver operatively connected to said vehicle ignition switch for receiving a coded signal representing a key security code from a transponder of said vehicle ignition key;
• and
• a vehicle immobilizer operatively connected to said receiver and selectively operable in a registration mode for registering said key security code, as one of a plurality of registered security codes, responsive to receipt of said coded signal and in an anti-theft mode for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal and said coded signal corresponding to a registered security code;
• wherein said vehicle immobilizer automatically switches from said registration mode to said anti-theft mode responsive to said receiver receiving said coded signal and said key security code being previously registered.

An anti-theft system for an automotive vehicle having an ignition switch, operable with an ignition key, and an engine comprising:

• a receiver operatively connected to said vehicle ignition switch for receiving a coded signal representing a key security code from a transponder of said vehicle ignition key;
• and
• a vehicle immobilizer operatively connected to said receiver and selectively operable in a registration mode for registering said key security code as one of a plurality of registered security codes responsive to receipt of said coded signal and in an antitheft mode for issuing a start signal to enable starting of the vehicle engine responsive to receipt of said coded signal and said coded signal corresponding to one of said plurality of registered security codes;
• wherein said vehicle immobilizer automatically switches from said registration mode to said anti-theft mode responsive to registration of said key security code as one of said plurality of registered security codes if a count of said plurality of registered security codes thereby equals an established maximum number of registered security codes.