Patent ID: 6128560
Filing Date: 2000-10-03
Classification: G01R

Abstract:
A diagnosis system for reading malfunction data from electronic control units used to control various functions of a vehicle, the system comprising:a plurality of electronic control units forming a communications network, wherein each control unit of the plurality of electronic control units stores data related to malfunctions;a diagnostic tester connected to the electronic control units via the communications network for reading the data stored in the electronic control units, wherein the diagnostic tester transmits an initialization signal at a predetermined low speed to the communications network when the diagnostic tester starts communicating with at least one of said electronic control units; anda selecting means located in at least one of the electronic control units for selecting a transmission rate between the communications network and the diagnostic tester from a plurality of transmission rates, that are faster than that of the initialization signal, based on a pulse width of the initialization signal.