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 troubleshootingInspection
Inspect cylinder head for warpage
Using a precision straightedge and feeler gauge,
measure the warpage of the contact surfaces of the
cylinder block and manifolds.
Maximum warpage:
0.08 Mm (0.0032 In.)
If the warpage is greater than the maximum, replace
the cylinder head sub-a ...
Data list / active test (2006/01- )
Read data list
Hint:
Using the intelligent tester's data list allows switch,
sensor, actuator and other item values to be read without
removing any parts. Reading the data list early in
troubleshooting is one way to save time.
Connect the intelligent tester (with can vim) to the
...
Electronic control
Removal and installation of battery
terminal
Notice:
Certain systems need to be initialized after
disconnecting and reconnecting the cable from
the negative (-) battery terminal.
Before performing electronic work, disconnect
the cable from the negative (-) battery terminal to
...