| 摘要 |
PROBLEM TO BE SOLVED: To provide a failure detection system of an exhaust pipe fuel injection system and a failure detection method of an internal combustion engine and the exhaust pipe fuel injection system, capable of easily determining presence or absence of failure in two opening/closing valves and the failed opening/closing valve in a passage for supplying a fuel to an exhaust pipe fuel injection device for injecting the fuel to an exhaust passage of the internal combustion engine, and preventing a state that a purification processing capacity of an exhaust emission control device is degraded, from being left as it is.SOLUTION: Occurence of opening sticking failure or closing sticking failure of one or both of a shutoff valve 31 and a dosing valve 32 is determined by comparing pressures P1, P2 of the first pressure P1 and the second pressure P2 based on combination of opening/closing states of the shutoff valve (first opening/closing valve) 31 and the dosing valve (second opening/closing valve) 32, with pressures PN1, PN2 at a normal time.SELECTED DRAWING: Figure 3 |
