Abstract: An operating fluid storage system for a motor vehicle having a reservoir with a filling opening and a closure cover which closes the filling opening and which can be removed from said filling opening to release the filling opening, and with at least one operating fluid outlet opening, to which an operating fluid conveyor line can be connected, for the output of operating fluid to a consumer, the system having a need sensor assembly and an output device, the need sensor assembly determines a filling need of the reservoir and outputs a corresponding need signal to the output device which acoustically, visually and/or haptically outputs a signal indicating the filling need; on the reservoir, an identification device is provided, which can be switched between at least two functional states and which is connected to the need sensor assembly via signal transmission, and which, when the need sensor assembly determines a filling need of the reservoir, is actuated by a corresponding need signal of the need sensor asse