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 troubleshootingHeated oxygen sensor
Components
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove heated oxygen sensor (for bank 1 sensor 2)
...
Solar sensor circuit (passenger side)
Description
The solar sensor, which is installed on the upper side of the instrument
panel, detects sunlight and
controls the air conditioning auto mode. The output voltage from the solar
sensor varies in accordance
with the amount of sunlight. When the sunlight increases, the output volt ...
Driving assist systems
To keep driving safety and
performance, the following
systems operate automatically
in response to various
driving situations. Be
aware, however, that these
systems are supplementary
and should not be relied
upon too heavily when operating
the vehicle.
Summary of the driving
assist systems
â– ABS ( ...