초록 ▼

An onboard diagnostic mechanism for a sealed vehicle fuel delivery system. By controlling fuel system valves, the electronic engine controller (EEC) periodically subjects the sealed system to an initial vacuum level, then monitors the pressure increase due to evaporative effects during a predetermin

An onboard diagnostic mechanism for a sealed vehicle fuel delivery system. By controlling fuel system valves, the electronic engine controller (EEC) periodically subjects the sealed system to an initial vacuum level, then monitors the pressure increase due to evaporative effects during a predetermined test interval. Excessive deviations in measured pressure compared to predetermined criteria produce indications of potential undesired operational conditions. To prevent fuel sloshing which results from aggressive driving or rough roads from producing false output indications, the instantaneous system pressure is compared with a rolling average of tank pressure to produce a difference signal indicative of fuel sloshing. If the resulting difference signal exceeds a predetermined threshold, the monitoring process is aborted in favor of a later test after the fuel sloshing condition terminates.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for detecting fuel sloshing in a sealed vehicle fuel supply system comprising:means for detecting the instantaneous vapor pressure within said sealed system at a position above the level of fuel in said system,means for generating a sequence of pressure signal v

[ What is claimed is:] [1.] Apparatus for detecting fuel sloshing in a sealed vehicle fuel supply system comprising:means for detecting the instantaneous vapor pressure within said sealed system at a position above the level of fuel in said system,means for generating a sequence of pressure signal values each indicating the magnitude of said instantaneous vapor pressure at one of a plurality of spaced time intervals,means for generating an average signal value indicative of an average of a plurality of said pressure signal values,means for generating a deviation signal value indicative of the difference between one of said pressure signal values and said average signal value, andmeans responsive to said deviation signal for producing an indication of the amount of fuel sloshing in said sealed fuel system.