Vehicle powertrain and a method for controlling a vehicle

The present disclosure relates to a method for controlling a vehicle powertrain and vehicle, or for controlling a vehicle powertrain having a transmission system and method to improve shift quality, the system and method for on-coming clutch detecting an initial rise time of the torque capacity, the initial rise time indicating the start of the torque phase. Initial rise time is detected by using the transmission input shaft torque calculation. The system may include a vehicle powertrain, the powertrain vehicle having an engine, a torque converter coupled to the engine through the transmission and a controller, the controller is configured to, a torque phase and an inertia phase characterized by the preparation phase during a shift event, when the difference between the first and the second transmission input shaft torque of the transmission input shaft torque exceeds a first predetermined threshold parameter, the torque phase control is started.