A method is provided for the operation of an assembly of a vehicle, whereas the assembly is transferable from an unactuated position into an actuated position by a pressure medium-actuated actuator if two redundant pressure medium valves both occupy a pressure supply position. For the functional test of one of the valves, a first valve is controlled to occupy the pressure supply position, and the second valve is controlled so as not to occupy the pressure supply position. If, upon this control of the two valves at the pressure medium-actuated actuator or at the assembly to be operated by the pressure medium-actuated actuator, no reaction is detected, there is a correct operation at a proper second valve. If, despite this control of the two valves, at the pressure medium-actuated actuator or at the assembly to be operated by the pressure medium-actuated actuator, a reaction is detected, there is an improper operation at a defective second pressure medium valve.