The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingHow to proceed with troubleshooting
Hint:
Use the following procedures to troubleshoot the occupant
classification system.
*: Use the intelligent tester.
Vehicle brought to workshop
Passenger airbag on/off indicator check
Dtc check (present and past dtc)*
Check for dtcs (see page rs-249 ).
Result ...
Transmitter id not registered in main mode
Description
Inspection procedure
Notice:
It is necessary to register an id code after replacing the tire pressure
warning valve and
transmitter and/or the tire pressure monitor ecu (see page tw-9).
Hint:
Set the tire pressure to the specified value.
Standard pressure:
220 kpa (2.2 ...
Front seat assembly (for manual seat)
Components
...