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 troubleshootingVc output circuit
Description
The ecm constantly generates 5 v power from the battery voltages supplied to
the +b (batt) terminal to
operate the microprocessor. The ecm also provides this power to the sensors
through the vc output
circuit.
When the vc circuit is short-circuited, the microprocessor in the ...
Horn relay
On-vehicle inspection
Remove engine room no. 1 Relay block cover
Inspect integration relay (unit a: horn relay)
Using a screwdriver, detach the 2 claws and
disconnect the integration relay from the engine
room junction block.
Hint:
Tape the screwdriver tip before use.
Mea ...
Rear center seat outer belt assembly
Components
Removal
Caution:
Wait at least 90 seconds after disconnecting the cable
from the negative (-) battery terminal to prevent airbag
and seat belt pretensioner activation.
Remove shoulder belt anchor cover rh
Using a screwdriver, remo ...