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 troubleshootingDeterioration of battery
Description
The ecm determines the battery power according to the voltage of the batt
terminal while the engine is
running (not cranking).
Inspection procedure
Inspect battery
Inspect the battery specific gravity.
Check the specific gravity of each cell.
Standard gravity: ...
Short to gnd in can bus line
(2005/11-2006/01)
Description
There may be a short circuit between the can bus line and gnd when there is
resistance between
terminals 6 (canh) and 4 (cg) or terminals 14 (canl) and 4 (cg) of the dlc3.
Wiring diagram
Inspection procedure
Notice:
Turn the ignition switch off b ...
If your vehicle has to be stopped in an emergency
Only in an emergency, such
as if it becomes impossible
to stop the vehicle in the
normal way, stop the vehicle
using the following procedure:
Stopping the vehicle
1. Steadily step on the brake
pedal with both feet and
firmly depress it.
Do not pump the brake pedal
repeatedly as this will increase t ...