Description & Operation: Notes
The multiplex control system uses a Body Control Module (BCM) and 11 Local Control Units (LCU's) to manage the following electrical systems in the vehicle: power window control, power door lock control, automatic drive positioner control, power seat control, time control system, anti-theft system, step light control, illumination control, door mirror automatic tilt down reverse control and multi-remote control. See Fig 1 . Some electrical systems are directly connected to the BCM, while some electrical loads and switches are connected to the appropriate LCU.
The BCM uses 2 data lines, connected between BCM and LCU's, to establish communication and control with each LCU. System has a sleep/wake-up control mode to turn on/shut off the communication between BCM and LCU's, as necessary, to prevent unnecessary power consumption. If computing function of the BCM is malfunctioning, system will set LCU's in fail-safe control mode.