GENERAL INFORMATION




  1. With the ignition key turned ON, the transponder (a small transmitter) integrated in the ignition key transmits its own encrypted code to the key ring antenna via radio wave.
  2. According to the sent encrypted code, the immobilizer-ECU controls the engine-ECU only when the sent encrypted code agrees with the pre-registered one.
  3. The system is designed to be maintenance-free because the power source for the transponder is supplied by the immobilizer-ECU. Two ignition keys are provided, and up to eight keys can be registered to one vehicle as needed. More than one trillion of encrypted code combinations can be registered, and parts of them are irregularly changed whenever the ignition key is turned ON. This feature prevents code copying, resulting in higher security of the system.

DIAGNOSIS CODE TABLE


Diagnosis code No.
 Diagnosis item
B1702
 Reception error of encrypted code
B1703
 Encrypted code inconsistent
B1722
 Antenna failure
B1731
 Communication error with the engine-ECU
B1761
 Chassis No. not recorded
B1766
 Transponder registered for other vehicle
U1073
 Bus off

CONSTRUCTION DIAGRAM




MAIN COMPONENTS


Component name
Outline of function
Transponder
 Is power-supplied by the key ring antenna. When the transponder receives random number data, the transponder processes random number data and the encrypted code. Then it transmits the process result to the immobilizer-ECU.
Key ring antenna
 The immobilizer-ECU supplies power via an antenna on a steering lock by transmission of electromagnetic waves to a transponder built into a key, using magnetic coupling
Immobilizer-ECU
  • Supplies electrical power to the transponder integrated in the ignition key, and transmits random number data.
  • Verifies the encrypted code which is sent from the transponder. If the code is correct, it sends an engine mobilization signal to the engine-ECU.

Engine-ECU
 Starts the engine, and then continues the engine running if an engine mobilization signal is confirmed. If an engine immobilization signal is confirmed, the ECU cancels the engine control and stops the engine.

ENCREPTED CODE REGISTRATION CRITERIA TABLE


caution Do not replace the engine-ECU and immobilizer-ECU simultaneously. Always replace the ECU by ones when the multiple ECU is replaced, and then replace the next ECU after registering the necessary IDs.

note The immobilizer-ECU can retain maximum eight different ignition key in the memory.
Item
 Operation contents and procedure
When the engine-ECU is replaced
 Write the Chassis No.
When the engine-ECU is rewritten (other than immobilizer system-related item)
 Operation is not needed
When the immobilizer-ECU is replaced
  1. Write the Chassis No.
  2. Register all ignition key encrypted code again
When the key ring antenna is replaced
 Operation is not needed
When the ignition key is added separately.
  1. Register all ignition key encrypted code again
  2. Register all ignition key keyless entry secret code again (with transmitter only)
When the ignition key is lost separately.
  1. Register all ignition key encrypted code other than the lost ignition key again
  2. Register all ignition key keyless entry secret code other than the lost ignition key again
When the ignition key is replaced by the set or the steering lock cylinder is replaced by the piece.
  1. Register all ignition key encrypted code again <Barcode No. input>
  2. Register all ignition key keyless entry secret code again (set supply only)
When the door lock cylinder, glove box lock assembly are replaced
 Register the replaced ignition key keyless entry secret code
Registration flow chart