Car electronic control system & method for controlling the same

摘要

A multiplex communication system for a car electronic control system comprises a plurality of control units connected to each other by a multiplex data communication line (7); and a microcomputer (11) provided in at least one of the control units and having a function of switching from a sleep mode to an operational mode, whereupon it issues a command to the other control units to cause them to shift to the operational mode. The microcomputer (11) is shifted to the operational mode when the input signal varies in the sleep mode to judge whether the input signal is normal or abnormal prior to starting usual operation. It starts the usual operation and issues a command to cause the other control units to be shifted to the operational mode when judging that the input signal is normal.