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 troubleshootingDiagnosis system
Bus check
Select "bus check" from the "obd / mobd
menu" screen.
Hint:
The ecus and sensors that are properly connected
to the can communication system can be displayed
using the intelligent tester via can vim.
Press "enter" on the intelligen ...
Check mode procedure
Check mode (signal check)
Connect the intelligent tester (with can vim) to the
dlc3.
Turn the ignition switch on.
Select the "signal check", and continue
checking with the intelligent tester.
Notice:
Select the "signal check" from the "dtc
check&quo ...
Multiplex communication circuit
Description
The air conditioning amplifier communicates data with the ecm and combination
meter through the can
communication system.
Wiring diagram
Inspection procedure
Check dtc
Clear the dtc (see page ac-31).
Read the dtc (see page ac-31).
Result
Go to can c ...