| 摘要 |
PROBLEM TO BE SOLVED: To sufficiently secure a frequency of diagnosis by properly diagnosing failure of opening and closing of a shut-off valve.SOLUTION: A fuel supply system comprises: a gas tank 42 for storing gas fuel in a high-pressure state; a first injection valve 21 for injecting the gas fuel; a pressure control valve 60 for adjusting injection pressure to be decreased; and a shut-off valve 45 provided in a high-pressure passage 51 and having a blocking function for blocking distribution of the gas fuel. A control part 80 outputs a closing command to the shut-off valve 24 in a predetermined diagnosis period during which the fuel is injected by the first injection valve 21, and outputs an opening command after a predetermined closing time has elapsed since the closing command. Then, during the diagnosis period, failure of opening and closing of the shut-off valve 45 is diagnosed on the basis of an integrated value of downstream side pressure detected by a high-pressure sensor 46 and a fuel injection amount by the first injection valve 21 from a timing when the closing command is outputted. |
