Component name
Outline of function
Receiver antenna
Receives the operation signals from the lock/unlock switches on the ignition key (transmitter and transponder), sends them to ETACS-ECU
Sends signal to the transponder in the ignition key and receives the reply data from the transponder via the steering lock (immobilizer antenna), sends the reply data to ETACS-ECU.
Communication with transponder is operated by ETACS, Receiver antenna is a driver module for transponder communication.
Steering lock (immobilizer antenna)
Wireless communication with ignition key (transponder) receives the ID code (key ID) of the ignition key (transponder) needed for starting the engine, transponder communication is conducted via this antenna and receiver antenna drives this antenna.
Ignition key (transmitter and transponder)
The ignition key (transponder) receives signals for certification sent from ETACS-ECU via receiver antenna and immobilizer antenna, and sends the reply data signal to ETACS-ECU via receiver antenna and immobilizer antenna.
The ignition key (transmitter) also sends signals to receiver antenna when the lock/unlock switches on it are operated.
Conduct certification communication with the engine by using the CAN communications.
Operate the receiver antenna for the transponder communication, and store the IDs using the immobilizer communication.
Communicates with ETACS-ECU via CAN. Permits/inhibits the engine starting and controls the engine operation.

System configuration


1.When the ignition key is inserted to the ignition switch or the ignition switch is turned to the ON position, ETACS-ECU starts operation of receiver antenna, and starts communication with ignition key (transponder) by radio frequency.
2.When the ignition key receives the request signal to start the communication from receiver antenna via immobilizer antenna, then transponder starts the communication and send the signal for communication to receiver antenna via immobilizer antenna.
3.Receiver antenna sends the codes (key ID, etc) sent from the ignition key to the ETACS-ECU.
4.ETACS-ECU compares the codes (key ID, etc) sent from receiver antenna with the already-registered ID code and self calculated value, and then reflect the result of transponder communication to the certification communication with engine ECU.
  • The transponder integrated in the ignition key uses the power supplied from receiver antenna via immobilizer antenna. Therefore, it can be used regardless of the battery in ignition key (for transmitter).
  • Two ignition keys (transmitter and transponder) are provided, and up to eight keys can be registered to one vehicle as needed.
  • When ETACS-ECU is replaced or when the key is lost or added, the ID codes for all the keys (key ID) must be registered using M.U.T.-III.