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 troubleshootingInstallation
Install throttle body
Install a new gasket onto the intake manifold.
Install the throttle body and fuel pipe clamp with the
4 bolts.
Torque: 30 n*m (305 kgf*cm, 22 ft.*Lbf)
Connect the fuel tube into the clamp.
Connect the wire harness clamp.
Connect the throttle posi ...
Operation check
Illuminated entry system operation check
The illuminated entry system controls the following
lights:
Ignition key cylinder light*1 or transponder key
amplifier*2
Foot light
Map light and room light
Hint:
*1: W/o engine immobiliser system
*2: W/ engine immobiliser ...
Front seat cushion heater
Inspection
Inspect front seat cushion heater
assembly lh
Measure the resistance of the seat cushion heater.
Standard resistance
If the result is not as specified, replace the seat
cushion heater assembly.
Heat the thermostat with a light.
Measure the resistance of the sea ...