| 摘要 |
PURPOSE:To decide the abnormality of an exhaust gas recirculation system accurately, by outputting an abnormality signal if the temperature in the exhaust gas recirculation system does not reach to a predetermined level within predetermined time after provision of an exhaust gas recirculation instruction. CONSTITUTION:A control unit 60 is inputted with detection values such as intake air quantity, intake tube negative pressure, vehicle speed, rotation, accelerator opening or cooling water temperature and provides an EGR valve drive signal A to an EGR valve 12 based on said information. If a value detected by a temperature sensor 16 arranged in an exhaust recirculation path does not reach to a predetermined level within a predetermined time after provision of the drive signal A, it is decided that the exhaust gas recirculation system is abnormal and an alarm lamp 26 is lighted. |
