IGNITION CIRCUIT DIAGNOSTIC DEVICE AND IGNITION CIRCUIT DIAGNOSTIC METHOD

To provide an ignition circuit diagnostic device capable of easily completing an ignition circuit diagnostic operation in a short time.SOLUTION: An ignition circuit diagnostic device 1 includes an ignition resistor 2, a first power line 3, a second power line 4, a first power supply 5, a second power supply 6, and a control unit 7. The first power line 3 has a first high potential power line 8 and a first low potential power line 9 for supplying a current from the first power supply 5 to the ignition resistor 2. The second power line 4 has a second high potential power line 10 and a second low potential power line 11 for supplying a current from the second power supply 6 and the ignition resistor 2. The control unit 7 is configured to control the first power supply 5 to supply a first current I1 and the second power supply 6 to supply a second current I2 so as to detect a failure on the ignition resistor 2 and an open failure on the first high potential power line 8, the second high potential power line 10, the first low potential power line 9, and the second low potential power line 11 based on a first potential VH and a second potential VL detected at a high potential end 2A and a low potential end 2B of the ignition resistor 2.SELECTED DRAWING: Figure 1 【課題】点火回路診断動作を容易に短時間で完了させることができる。【解決手段】点火回路診断装置１は、点火抵抗２と第１給電路３と第２給電路４と第１電源５と第２電源６と制御部７とを含む。第１給電路３は、第１電源５から点火抵抗２へ電流を供給するための第１高電位給電路８と第１低電位給電路９とを有し、第２給電路４は第２電源６から点火抵抗２へ電流を供給するための第２高電位給電路１０と第２低電位給電路１１とを有する。制御部７は、第１電源５に第１電流Ｉ１を供給させ、かつ、第２電源６に第２電流Ｉ２を供給させ、点火抵抗２の高電位端２Ａおよび低電位端２Ｂで検出される第１電位ＶＨと第２電位ＶＬとに基づいて、点火抵抗２の故障検出と、第１高電位給電路８、第２高電位給電路１０、第１低電位給電路９、第２低電位給電路１１のオープン故障の検出が可能である。【選択図】図１