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 troubleshootingRear no. 1 Seat assembly (for lh side)
Components
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If your vehicle needs to be
towed
If towing is necessary, we
recommend having your
vehicle towed by your
Toyota dealer or commercial
towing service, using a
wheel-lift type truck or flatbed
truck.
Use a safety chain system
for all towing, and abide by
all state/provincial and local
laws.
Situations when it is necessary
to contact d ...
Light control switch circuit
Description
This circuit detects the state of the headlight dimmer switch.
Wiring diagram
Inspection procedure
Read value of intelligent tester (main body ecu)
Connect the intelligent tester to the dlc3.
Turn the ignition switch on and press the intelligent
tester main switch on ...