Description & Operation
The multiplex control system consists of a body control Electronic Control Unit (ECU), power seat ECU, remote control mirror ECU, tilt/telescopic ECU, and related wiring (communication bus). See Fig 1. Some electrical systems are directly connected to the body control ECU, while some electrical loads and switches are connected to the appropriate ECU. The multiplex control system is also equipped with a self-diagnostic function. The communication bus is self-diagnosed by the body control ECU which stores an appropriate Diagnostic Trouble Code (DTC) if a fault is detected.
NOTE:
The body control ECU is also referred to as instrument ECU or instrument panel ECU.