Abstract: A trouble-diagnosis multi-function tester for diagnosing presence or absence of occurrence of trouble by centralized inputting of the operational information in every element of the vehicle, which is constructed with a tester which introduces input information of various vehicles through a centralized connector provided at the side of the vehicle, and displays the contents of the input information; and a computer which controls the vehicle information to be transmitted as an output through an outer expansion terminal of the tester.

Abstract: A trouble-diagnosable multifunction testing apparatus is disclosed for use with a first half part of a collective connector provided in an automotive vehicle, the first half part of the collective connector including a plurality of signal lines connected respectively to a plurality of electronic control units disposed in the vehicle for transmitting a trouble-diagnosis output signal or various data signals obtained from each of the plurality of electronic control units, and a common switchable signal line connected with each of the plurality of electronic control units for transmitting an electric signal having a first or second logic level, the first half part of the collective connector being connected operatively with both of the signal lines, respectively. When a conventional test unit is connected to the first half connector part, the electronic control units transmit data signals to it at a first rate.

Abstract: A failure hysteresis memory device which is constructed with a vehicle-side connector to be connected to a plurality of electronic control devices mounted on the vehicle; a tester-side connector to be connected to a trouble-diagnosis multi-function tester or a display device; signal conversion device for converting a signal from the vehicle-side connector to produce an output signal to the tester-side connector; a memory unit to store therein the output signal converted by the signal conversion means; and a micro-computer which processes information contained in the input signal and controls the constituent members.