| 摘要 |
<p>PURPOSE:To diagnose a plural number of parts that can be causes of deterioration of exhaust gas and realize the trouble diagnostic device of an internal combustion engine for making highly accurate trouble diagnosis. CONSTITUTION:A diagnostic range is judged from output signals of an air quantity sensor 5 and a rotational speed sensor 6 by means of a diagnostic range judging unit 19. Deterioration of exhaust gas is judged from the signal S4 of an oxygen sensor 4 by an output judging unit 20. Deterioration degrees of an ignition plug, a catalyst converter 2, a front oxygen sensor 3 are calculated by the ignition deterioration calculation part 18A, the catalyst deterioration calculation part 18B and the oxygen sensor deterioration calculation part 18c of a deterioration calculation unit 18, and each deterioration degree is put in comparison process deterioration degree comparison unit 22. A deterioration maximum part is specified by a deterioration degree maximum specific part 23, from the comparison result. A signal which shows the deterioration maximum part specified by the deterioration maximum specified part 23 is supplied and stored in a memory unit 24, and also a trouble generation alarm signal is supplied to an inter-vehicle display means.</p> |
