The functional inspection methodological null tank of the tank ventilating system in

摘要

PROBLEM TO BE SOLVED: To detect the oversight of error diagnosis on the basis of inappropriate use by deciding and memorizing a tank liquid level at the time of start and completion of a stop, generating a difference between liquid levels, and outputting an error message only when the difference does not exceed a predetermined threshold value. ;SOLUTION: It is specified by measuring current supplied to a pump motor whether flow supplied from a pressure source 50 is different from supplying flow which exists when excessive pressure is supplied through a reference leakage 81 or not. When an engine is stopped, the liquid level in a tank is measured and memorized. And the other of the liquid level in the tank is measured and memorized, and a difference between the measured liquid level and a memorized liquid level is decided. It is decided whether the difference exceeds a predetermined threshold value or not. In the case where the difference is not larger than the threshold value, the existence of leakage is presumed, and an error message is outputted. It is thus possible to detect error diagnosis oversight due to inappropriate use.;COPYRIGHT: (C)2000,JPO