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 troubleshootingOil pump
Components
Removal
Remove chain sub-assembly
Remove the chain (see page em-22).
Remove oil pump assembly
Remove the 3 bolts, oil pump and gasket.
Disassembly
Remove oil pump strainer
Remove the 2 nuts, oil pump strainer and gasket.
...
Front brake
Components
Removal
Hint:
Use the same procedures for the lh side and rh side.
The procedures listed below are for the lh side.
Remove front wheel
Drain brake fluid
Notice:
Wash off brake fluid immediately if it comes in
contact with any painted surface.
Disconnec ...
Battery current sensor
On-vehicle inspection
Check battery current sensor assembly
Measure the resistance of the sensor.
Standard resistance
If the result is not as specified, replace the sensor
assembly.
Measure the resistance of the sensor.
Standard resistance
If the result is not as specified, ...