METHOD AND SYSTEM FOR EVALUATING HYDROSTATIC TRANSMISSION USING CHARGE PRESSURE

A method of diagnosing a hydrostatic transmission system includes defining an initial charge pressure of a charge pump at a defined operating position of a primary pump. The primary pump is controlled to operate at the defined operating position. A current charge pressure from the charge pump is sensed when the primary pump is operating at the defined operating position. A pressure difference between the initial charge pressure of the charge pump and the current charge pressure of the charge pump is calculated and correlated to a system state of health of the hydrostatic transmission system.