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 troubleshootingComponents (2005/11-2006/01)
Sliding roof ecu power source circuit
Description
If the sliding function and tilt function do not operate, there may be a
malfunction in the sliding roof ecu
power source circuit.
Wiring diagram
Inspection procedure
Perform active test by i ...
Components
...
Motor terminal voltage malfunction
Description
The power steering ecu supplies the current to the power steering motor
through the motor circuit.
Wiring diagram
Inspection procedure
Read value of intelligent tester (motor voltage)
Connect the intelligent tester (with can vim) to the
dlc3.
Turn the ignitio ...