Abstract: A control method for a manual back-up electro-hydraulic braking system in which the rear service brakes of the vehicle are intentionally operated in a manual back-up mode under specified non-failure operating conditions to conserve electrical energy. The manual back-up mode for the rear service brakes is initiated if braking is commenced while the vehicle speed is below a near-zero threshold speed. If braking is commenced above the threshold speed, the manual back-up mode for the rear service brakes is initiated when the vehicle speed falls below the threshold and the pressure command for the rear brakes has been substantially constant for at least a predetermined time. In this case, the rear manual back-up mode is initiated by reducing the rear brake pressure command to the rear boost units at a controlled rate until the rear brake pressure reaches the manually developed pressure, and then entering the manual back-up mode.