A method of operating a vehicle
powertrain system comprising an
electric motor and transmission where the
electric motor is operably and selectively coupled to the transmission and adapted to provide an output torque contribution thereto, and the
electric motor has a predetermined maximum motor output torque and a predetermined minimum motor output torque which are used to determine a range of permissible control points for at least one transmission control parameter. The method includes establishing a
motor torque reserve by performing at least one of decreasing the predetermined maximum motor output torque to a maximum reserved motor output torque and increasing the minimum motor output torque to a minimum reserved motor output torque, wherein the maximum reserved motor output torque and the minimum reserved motor output torque are used in place of the predetermined maximum motor output torque and the predetermined minimum motor output torque, respectively, to determine the range of permissible control points for the at least one transmission control parameter. The
motor torque reserve may include a static
motor torque reserve, a dynamic motor torque reserve, or a combination of both static and dynamic torque reserves. The dynamic torque reserve may include a predictive dynamic reserve, a reactive dynamic reserve, or a combination of a predictive reserve and a reactive reserve or reserves.