A tractor control system, which controls an operating condition of an implement attached to the tractor. The control system includes a sensing means providing a force signal which indicates the pull force necessary to pull an implement in a desired position; a control which receives the force signal; and means for measuring at least one parameter associated with the tractor mode and/or the implement mode and the implement position is adjusted to a new position when the force signal varies. The control system includes pre-determined values associated with certain tractor and/or implement modes. A measured parameter is compared with a pre-determined parameter value and if the measured parameter would result in an undesired movement of the implement, the force signal is deactivated, or the response to the force signal is deactivated to prevent undesired movement of the attachment.