Overall diagnosis apparatus for vehicle-mounted control devices

Abstract

A plurality of control systems mounted on a vehicle such as an automobile, and provided for different controlled objects are respectively made of control computers. These control computers are linked by a common data bus. These computers exclusively execute, for example, an engine control, a transmission control, a brake control, a suspension control, and a auto drive control. The data bus is further connected to a diagnosis computer. Each control computer detects a signal from the sensor provided corresponding to each controlled object, and outputs the detect signal to the data bus. Each control computer executes the logical operation for its control on the basis of its detect signal and various data transferred to the data bus. The diagnosis computer supervises an operating state of each control system on the basis of the data transferred to the data bus. When an abnormality is detected, the diagnosis computer stores this data in a large-capacity memory, and displays the abnormality.