A method and system for controlling a powertrain

An improved method for controlling a powertrain is disclosed in which the method estimates an input torque to a continuously variable transmission 11. The method includes calculating torque adaptation coefficients when the torque converter clutch is unlocked, and an accurate torque value can be obtained based on the torque converter characteristics. The adaptation coefficients are then used to correct the transmission torque estimate, which is then used to determine ideal clamping forces for the continuously variable transmission 11.