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 troubleshootingSteering column assembly
Components
Removal
Caution:
Some of these service operations affect the srs airbag
system. Read the precautionary notices concerning the
srs airbag system before servicing the steering column
(see page rs-1).
Place front wheels facing straight ahead
Disconnect cab ...
Brake front brake flexible hose
Components
Removal
Hint:
Use the same procedures for the lh side and rh side.
The procedures listed below are for the lh side.
Remove front wheel
Drain brake fluid
Notice:
Wash off brake fluid immediately if it comes in
contact with any painted surface.
Remove front flex ...
Precaution
Inspection procedure for vehicle involved
in accident
Perform the zero point calibration and sensitivity
check if any of the following conditions apply.
The occupant classification ecu is replaced.
Accessories (seat cover etc.) Are installed.
The front passenger seat is remove ...