Abstract: The invention relates to power management of a off-highway vehicle. A power management apparatus is described as a vehicle control unit coupled to a vehicle and the vehicle control unit is in communication with an engine and a transmission controller. In response to power management input, the vehicle control unit sends a message to the transmission controller commanding a maximum torque limit based on the maximum drivetrain torque. The maximum torque limit is configured to optimize power to the vehicle implement.

Abstract: A transmission controller determines a requested engine torque value. For an upshift the requested engine torque value is determined as a function of slippage of one of an off-going clutch. For a downshift, the requested engine torque value is determined as a function of actual sensed engine torque. The requested torque value is sent to an engine controller which controls the engine so that the engine generates the requested engine torque. Then the appropriate transmission clutches are swapped to complete the requested shift while the engine torque is controlled. The engine controller also limits engine torque to the requested engine torque value.