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 troubleshootingData 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
...
Light bulbs
You may replace the following
bulbs by yourself. The
difficulty level of replacement
varies depending on
the bulb. If necessary bulb
replacement seems difficult
to perform, contact your
Toyota dealer.
For more information about
replacing other light bulbs,
contact your Toyota dealer.
Preparing for ...
Air inlet control servo motor
Components
Removal
Remove blower assembly
Remove the blower (see page ac-203).
Remove air inlet control servo motor (see
page ac-210)
Inspection
Inspect air inlet control servo motor (for automatic air conditioning
system)
Inspect the servo motor operation. ...