Abstract: A draft force imposed upon a tractor by a ground engaging member of an implement attached with the tractor is controlled. A signal in a drivetrain of the tractor is detected, wherein the signal may be an electrical signal such as a voltage or current signal representative of a sensed draft force imposed upon the tractor by the ground engaging member of the implement attached with the tractor. The detected drivetrain signal may also be a data signal representative of the sensed draft force. The sensed signal representative of the sensed draft force is compared with a desired draft force. An output signal is generated based on a difference between the sensed current representative of the sensed draft force and the desired draft force. The generated output signal may be used to effect a vertical movement of the ground engaging member of the implement relative to the ground.