VEHICLE HYDRAULIC SYSTEM MONITORING SYSTEM AND METHOD

摘要

A system and method are provided for monitoring a vehicle hydraulic syst em having a plurality of hydraulic function elements. The hydraulic system includes a hydraulic pump for supplying pressurized hydraulic fluid to the plurality of hydraulic function elements via a corresponding plurality of hydraulic element control valves, an electronic control unit for controlling the element control valves. The pump also supplies lube fluid to a lubrication circuit if requirements of the hydrauli c function elements are met. The method includes sensing a hydraulic pressure (preferab ly the tube pressure of lube fluid in the tube circuit), and comparing the sensed pressure to a threshold pressure. If the sensed pressure is less than threshold pressure , then actively engaged hydraulic elements are tested by disengaging the elements i n a predetermined manner, checking to see if the sensed low pressure condition i s eliminated. If the sensed low pressure condition is eliminated after disengaging an element, then the leaking hydraulic function element (the last element disengaged) is deactivated (locked-out) and a corresponding message is generated and stored .