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 troubleshootingIf the engine
will not start
If the engine will not start even though correct starting procedures
are being followed („_p. 197, 200), Consider each of the following
points:
The engine will not start even though the starter motor operates
normally.
One of the following may be the cause of the problem:
There may not be ...
Short in front driver side - side squib circuit
Description
The driver side - side squib circuit consists of the center airbag sensor and
the front seat side airbag lh.
This circuit instructs the srs to deploy when the deployment conditions are met.
These dtcs are recorded when a malfunction is detected in the driver side - side
sq ...
Headlight relay
On-vehicle inspection
Remove headlight relay
Remove the headlight relay from the engine room
no. 2 Relay block.
Measure the resistance of the relay.
Standard resistance
If result is not as specified, replace the relay. ...