| 摘要 |
PROBLEM TO BE SOLVED: To diagnose failure of a one-way valve which is interposed in a pipe for introducing an inlet negative pressure for an engine to a vacuum servo. SOLUTION: While a brake is not operated (S1), an inlet negative pressure is calculated (S4) based on a suction air quantity (S2) and a throttle valve opening (S3). The calculated inlet negative pressure of the engine and the negative pressure in a vacuum servo detected by a negative pressure sensor (S5) are relatively compared to each other in a fixed time (S6) and, when the inlet negative pressure of the engine and the negative pressure in the vacuum servo are synchronously increased/decreased, it is diagnosed to be the seat failure of the one-way valve. |
