| 摘要 |
PURPOSE:To prevent close of a reflux passage due to solid content in exhaust gas, by a method wherein, when the temperature of exhaust gas is detected and the detected temperature is below a given value, it is decided that no exhaust gas flows through an exhaust gas reflux passage, and an alarm is sounded. CONSTITUTION:When a negative pressure in a negative pressure passage 5 exceeds a given value under a given running state, an EGR valve is opened to effect reflux of exhaust gas. In which case, a vacuum switch 9 is closed, a timer is set to an initial value by an ECM82 in an alarming device 8, and an A/D converted input signal from a thermo sensor 10 is read by an A/D converter 81. An input siganl from the thermo sensor 10 is read after a given time lapsed, and if the level of an input signal is below a given value, it is decided to be under a state in that there is not reflux of exhaust gas to a passage. This causes a signal to be outputted from the ECM82, a warning lamp 84 to be lighted ON with a transistor 83 turned ON, and an alarm to be sounded. |
