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 troubleshootingHydraulic test
Measure line pressure
Notice:
Perform the test at the normal operating atf
temperature: 50 to 80°c (122 to 176°f).
The line pressure test should always be
performed with at least 2 people. One person
should observe the condition of the wheels or
wheel chocks while the other ...
Dtc check / clear
Check dtc
Connect the intelligent tester (with can vim) to the
dlc3.
Turn the ignition switch on and turn the intelligent
tester on.
Select the following menu items: diagnosis /
obd/mobd / immobiliser / dtc info /
current codes.
Check dtcs and then write them down.
Hint ...
Removal
(2006/01- )
Remove front wheel
Drain automatic transaxle fluid
Drain the automatic transaxle fluid for u140f (see
page ax-147).
Drain the automatic transaxle fluid for u241e (see
page ax-146).
Drain the automatic transaxle fluid for u151e (see
page ax-172).
Remove front axle hub nut ( ...