| 摘要 |
PROBLEM TO BE SOLVED: To provide a failure detection device for effectively detecting a failure of a PCV valve without increasing dedicated structural components for failure detection and without causing an increase in size and cost.SOLUTION: An engine 1 includes an EGR valve 18 for controlling the flow rate of EGR gas. A blow-by gas returning passage 66 makes blow-by gas generated in the engine 1 flow into a surge tank 3a for returning it to the engine 1. A PCV valve 67 is operated by receiving a negative pressure for controlling the flow rate of the blow-by gas in the return passage 66. An electronic control unit (ECU) 50 fixes a throttle valve 21 at a predetermined slight opening during a fuel cut to decelerate the engine 1, controls the EGR valve 18 to be forcibly opened from a closed state to change the negative pressure of intake pressure in the surge tank 3a, and determines whether the PCV valve 67 has a fixture failure or not on the basis of a change in the amount of the intake air detected by an air flow meter 54 before and after changing the negative pressure. |
