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 troubleshootingSliding roof switch assembly
Removal
Disconnect cable from negative battery terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove map light assembly
Using a clip remover, detach the 4 ...
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 u151f (see
page ax-173).
Remove front axle hub nut ( ...
Parking brake lever
Components
On-vehicle inspection
Check parking brake switch assembly
Remove the rear console box (see page ip-16).
Hint:
Refer to the procedures from the removal of the no.
1 Console upper panel garnish up until the removal
of the rear console box sub-assembly.
Discon ...