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 troubleshootingTerminals of ecu
Check transponder key amplifier
Disconnect the e5 amplifier connector.
Measure the resistance of the wire harness side
connector.
If the result is not as specified, there may be a
malfunction in the wire harness.
Reconnect the e5 amplifier connector.
Measure the resist ...
Wireless remote
control/electronic
key battery
Replace the battery with a new one if it is depleted.
You will need the following items:
Flathead screwdriver
Small flathead screwdriver
Lithium battery cr2016 (vehicles without a smart key system), or
cr2032 (vehicles with a smart key system)
Replacing the battery
Vehicles without a ...
Customer problem analysis
Hint:
In troubleshooting, confirm that the problem symptoms
have been accurately identified. Preconceptions should be
discarded in order to make an accurate judgment. To
clearly understand what the problem symptoms are, it is
extremely important to ask the customer about the
problem an ...