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 axle hub and bearing
Components
On-vehicle inspection
Remove rear wheel
Disconnect rear drive shaft assembly lh
(for 4wd)
Disconnect the drive shaft (see page ds-69).
Remove rear disc brake cylinder assembly
lh (see page br-55)
Remove rear disc (see page br-57)
Check bearing backlash a ...
Check for short circuit
If the wire harness is ground shorted (fig. 5), Locate
the section by conducting a resistance check with
the body ground (below).
Check the resistance with the body ground.
Disconnect connectors a and c, and measure
the resistance
Standard resistance (fig. 6)
Hint:
Measure ...
Tc and cg terminal circuit
Description
Dtc output mode is set by connecting terminals tc and cg of the dlc3.
The dtcs are displayed by blinking the srs warning light.
Hint:
Make sure that dtc b1281 has not been output. If dtc b1281 has been
output, refer to the multiplex
communication system.
When each warning ...