Hydraulic system for an automatic transmission of a motor vehicle

A hydraulic system for an automatic transmission, in particular a dual-clutch transmission, of a motor vehicle, comprising:

• a high-pressure circuit, in which a pressure accumulator, at least one clutch, and gear selectors and at least one hydraulic pump are arranged, which is operated via an electronic control unit, wherein the pressure accumulator is connected via at least one hydraulic path to a hydraulic positioning cylinder, from which a control valve that can be operated by the control unit is connected upstream, with which control valve a hydraulic pressure applied to the hydraulic positioning cylinder is adjusted, which control valve can be adjusted between two flow-through positions in order to displace a piston in opposing piston strokes via opposing piston positioning distances and piston speeds in the hydraulic positioning cylinder, wherein each piston stroke is linked to a hydraulic fluid removal from the hydraulic system, wherein the control unit includes a diagnostic module, using which a delivery volume flow diagnosis is performed, during which an analysis unit determines an actual delivery volume flow and compares the actual delivery volume flow to a target delivery volume flow and, if there is a significant deviation, diagnoses a fault which is stored in a delivery volume flow fault memory.