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 troubleshootingPrecaution
Inspection procedure for vehicle involved
in accident
Perform the zero point calibration and sensitivity
check if any of the following conditions apply.
The occupant classification ecu is replaced.
Accessories (seat cover etc.) Are installed.
The front passenger seat is remove ...
Abs warning light remains on
Description
If any of the following conditions are detected, the abs warning light
remains on:
The ecu connectors are disconnected from the skid control ecu.
There is a malfunction in the skid control ecu internal circuit.
There is an open or short in the wire harness between the combinat ...
Test mode procedure
Test mode check
Hint:
When entering the test mode, the tire pressure
warning ecu sets all the test dtcs first. After
completing the test mode for each inspection item, the
dtcs that are determined normal by the tire pressure
warning ecu will be erased.
The dtcs for other inspec ...