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 troubleshootingBlower motor circuit
Description
When the heater control (blower switch) is set to position 1 or higher, the
contact of the htr relay is
closed, current flows to the blower motor, and the blower motor operates. The
blower motor speed can be
changed by exchanging the ground and the blower resistor circuit with the ...
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 no. 1 Engine cover (see page es-410)
Remove air cleaner cap (see pag ...
Front airbag sensor rh circuit malfunction
Description
The front airbag sensor rh consists of the diagnostic circuit, the frontal
deceleration sensor, etc.
If the center airbag sensor assembly receives signals from the frontal
deceleration sensor, it determines
whether or not the srs should be activated.
Dtc b1610/13 is recor ...