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 troubleshootingThrottle actuator control motor circuit
Description
The throttle actuator is operated by the ecm and opens and closes the
throttle valve using gears.
The opening angle of the throttle valve is detected by the throttle position (tp)
sensor, which is mounted
on the throttle body. The tp sensor provides feedback to the ecm. This ...
Disassembly
Caution:
Wear protective gloves. Sharp areas on the seat frame
(with adjuster) may injure your hands.
Hint:
Use the same procedures for the rh side and lh side.
The procedures listed below are for the lh side.
Remove vertical adjuster cover lh (for driver side)
Using a screw ...
System description
Key reminder warning system description
When the driver side door is opened with the key in
the ignition key cylinder and ignition switch in the
acc or off position, this system causes the key
reminder warning buzzer to sound in order to warn
the driver that the ignition key has not ...