Kia Optima: Description

Body control module receives various input switch signals controlling time and alarm functions for the intermittent wiper timer, washer timer, rear defogger timer, seat belts warning, central door lock, ignition key reminder, power window, door warning, tail lamp, crash door unlock, ignition key hole illumination, rear fog lamp control and keyless entry & burglar alarm.

BCM, SJB(Smart Junction Box) and CLU(Instrument Cluster) are connected by CAN line.

The nearest module with input switch or actuator receives the input data to reduce the wiring and then send input data to the others which need them via CAN lines.

In case of sending output, it is used to CAN communication, not wiring.

SJB can also control relays and IPS.

So Each module allots the current data and actuation data.