side can be minimized for example for coasting with engaged gears at a minimum system pressure the gear set pump rs pu may also be used for coasting exit processes for example for filling the clutches furthermore the excess volume flow of cooling oil flows to the oil cooler if the conditions for the second operating mode bm 2 are met and the predetermined speed threshold is also not reached the oil supply is carried out by the hydraulic pump rs pu controlled on the gear set side with the support of the hydraulic pump fzp pu controlled on the drive side in this operating mode bm 2 the motor vehicle coasts at a low vehicle speed for example less than twenty 20 km h in this driving state the delivery capacity of the hydraulic pump rs pu controlled on the gear set side is no longer sufficient for maintaining the system pressure at that point the retaining pressure valve is accordingly supplied such that the hydraulic pump fzp pu controlled on the engine side may supplement the volume flow of oil up to the predetermined target volume flow if the conditions for the third operating mode bm 3 are met the retaining valve is deactivated whereas the volume flow of cooling oil is used by the hydraulic pump rs pu controlled on the gear set side for cooling the gear set in this operating mode bm 3 the retaining valve is pressed to the end stop through the corresponding supplying of the electric pressure regulator eds this means that the functionality of the retaining valve is deactivated in this position the retaining valve is opened and the volume flow of cooling oil from the hydraulic.