The invention relates to a valve for controlling volumetric flows in a heating and/or cooling system of a motor vehicle, comprising a valve housing (10), from which at least one inlet channel (18) andat least one outlet channel (20, 22) branch, in addition to at least one disc-type valve body (28) for controlling the flow, the body being located in the valve housing so that it can rotate about the axis (31) of a driven shaft (30). According to the invention, the valve body (28) is operatively connected to an electromotive drive (24) by means of a gear system (64). The invention also relates to a heating and/or cooling system (110) of a motor vehicle, comprising a valve (131) of the type.