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 troubleshootingCheck mode procedure
Description
Check mode has a higher sensitivity to malfunctions
and can detect malfunctions that normal mode
cannot detect. Check mode can also detect all the
malfunctions that normal mode can detect. In check
mode, dtcs are detected with 1 trip detection logic.
Check mode pro ...
If 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 ...
Engine (ignition) switch
(vehicles without a
smart key system)
Starting the engine
Check that the parking brake is set.
Check that the shift lever is set in p.
Firmly depress the brake pedal.
Turn the engine switch to the “start” position to start the engine.
Changing the engine switch positions
“Lock”
The steering wheel is locked an ...