System for self-diagnosis of internal combustion engine

Abstract

Abstract PURPOSE:To obtain the self-diagnostic system of an internal combustion engine to which the competence of an obstacle self-diagnosis is imparted, by performing diagnosis with respect to output corresponding only under a certain input condition. CONSTITUTION:The output signal such as a fuel injector control signal is generated from a control circuit 46 and a drive circuit 18a in response to the ignition signal as the input signal from a wave form shaping circuit 21. This input signal and the output signal are inputted to a self-diagnostic circuit 47 while a non-obstacle signal from an ignition signal generating circuit coms to the opening and closing signal of a NOR gate 44 and obstacle display is performed through a fuel injector obstacle display part 15b only when the input signal is novmal and the output signal is absent and error diagnosis judging such a case that the input and the output signals are absent as an obstacle is not generated. In addition, input inferiority is displayed by a fuel injector fault display part 15b. By this mechanism, errorroneous diagnosis is prevented and the self-diagnostic system of an internal combustion engine to which the accuracy of obstacle diagnosis is imparted is obtained.

Inventors

• 👤 Toshio Takahashi
• 👤 敏夫 高橋

Bibliographic Details