Shift control method for vehicle powertrain

A shift control method for a vehicle powertrain, the shift control method comprising:

• calculating, by a controller configured to divide a shift process into a series of shift phases and perform shift control based on the shift phase, a control hydraulic pressure basic calculation value for implementing a necessary torque of a control target shift element based on the shift phase by using a control matrix created from a vehicle powertrain model;
• calculating a control hydraulic pressure correction calculation value by correcting the control hydraulic pressure basic calculation value with a correction value including a learning value for the shift element;
• and
• controlling the control target shift element on the basis of the control hydraulic pressure correction calculation value;
• wherein in the calculating of the control hydraulic pressure basic calculation value, the controller calculates the control hydraulic pressure basic calculation value by using predetermined back-up data when a predetermined reference shift phase for specifying data required to calculate the control hydraulic pressure basic calculation value does not exist.