| 摘要 |
PURPOSE:To perform the accurate opening detection of a reflux quantity control valve, by operating the reflux quantity control valve for its opening, while installing a control circuit which controls operation of a solenoid valve in order to scrub the surface of a resistor with a brush. CONSTITUTION:A reflux quantity control valve 11 is interposingly installed in the point midway in an exhaust reflux flow passage which is branched off from a suction passage 5 of an engine E and to be connected to an exhaust pipe 9. A control circuit 38 operates the reflux quantity control valve 11 for its opening and controls operation of a solenoid valve 21 in order to scrub the surface of a resistor when an operating state of the engine E is in the specified operating state out of a region to do exhaust reflux quantity control. Thus, abrasion powder to be produced on the surface of the resistor is wiped clean so that accurate opening detection for the reflux quantity control valve is performable. |
