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 troubleshootingPower steering ecu communication stop mode
Description
Wiring diagram
Inspection procedure
Notice:
Turn the ignition switch off before measuring the resistances of the
main wire and the branch
wire.
After the ignition switch is turned off, check that the key reminder
warning system and light
reminder warning system ...
Antenna coil open / short
Description
The transponder key coil receives key code signals from the transponder chip
in the key grip. The coil
built into the transponder key amplifier amplifies the key code signals and
outputs the signal to the
transponder key ecu.
Wiring diagram
Inspection procedure
R ...
Using the interior lights
Interior lights list
Interior lights
Interior/personal lights
Engine switch light (if equipped)
Cup holder light (if equipped)
Interior lights
Front
Off
Door position
The interior lights come on when
a door is opened. They turn off
when the doors are closed.
On
...