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 troubleshootingWhat to do if...
(Troubleshooting)
If there is a problem with the hands-free system or a bluetooth®
device, first check the table below.
When using the hands-free system with a bluetooth® device
When registering/connecting a cellular phone
When making/receiving a call
When using the contact list
W ...
Dtc check / clear
Check dtc
Dtcs which are stored in the ecm can be displayed
with the intelligent tester.
The intelligent tester can display pending dtcs and
current dtcs. Some dtcs are not stored unless a
malfunction is detected in consecutive driving
cycles. When a malfunction is detected ...
Compressor and pulley (for 2gr-fe)
Components
Removal
Discharge refrigerant from
refrigeration system (see page ac-172)
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 pretensione ...