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 troubleshootingData list / active test
Read data list
Hint:
Using the intelligent tester's data list allows switch,
actuator and other item values to be read without
removing any parts. Reading the data list early in
troubleshooting is one way to save time.
Connect the intelligent tester (with can vim) to the
dlc3.
Turn ...
Calibration
Description
After replacing components relating to the vsc or
performing "front wheel alignment adjustment",
clear and read the sensor calibration data.
Follow the chart to perform calibration.
Clear zero point calibration data (when using
intelligent tester)
...
Side airbag sensor
Components
On-vehicle inspection
Check side airbag sensor (vehicle not
involved in collision)
Perform a diagnostic system check (see page rs-
49).
Check side airbag sensor (vehicle involved
in collision and airbag has not deployed)
Perform a diagnostic system check ( ...