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 troubleshootingPressure control solenoid "A " performance (shift solenoid valve sl1)
Description
The ecm uses signals from the vehicle speed sensor to detect the actual gear
position (1st, 2nd, 3rd or
o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect mechanical
problems of the shift solenoid valves, valve body or automatic ...
Data list / active test
Read data list
Hint:
Using the intelligent tester's data list allows switch,
sensor, actuator and other item values to be read without
removing any parts. Reading the data list early in
troubleshooting is one way to save time.
Connect the intelligent tester (with can vim) to the
dlc3 ...
Front console illumination
On-vehicle inspection
Inspect front console illumination
Connect the battery's positive (+) lead to terminal 1
and the negative (-) lead to terminal 2, then check
that the light comes on.
Ok:
light comes on.
If the result is not as specified, replace the front
console illumin ...