An electronic control unit, has a casing accommodating a printed circuit board. The casing has a molded plastic intermediate structure having a frame. Two electrically conductive members are partially embedded in the intermediate structure during the course of molding and are connected to the printed circuit board forming output terminals of the control unit. Two flexible conductors, provided with corresponding electrically insulating coverings, connect the control unit to an apparatus to be controlled. Each conductor has an end permanently connected to a respective one of the conductive members and the connection between the conductors and the conductive members are covered and sealed in a fluid-tight way by an electrically insulating material.