| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that diagnosis accuracy degrades for a failure diagnosis of an intake valve of a high-pressure fuel pump if a fuel pressure instantaneously falls below a target fuel pressure due to a pulsation width of the fuel pressure, a noise of an output signal from a fuel pressure sensor or the like or if a response delay occurs until the fuel pressure changes (falls).SOLUTION: A failure diagnosis of an intake valve of a high-pressure fuel pump is conducted on the basis of lapsed time for determining permission to conduct the failure diagnosis and a failure diagnosis threshold computed on the basis of a state of an engine. |
