Method for Operating a Vehicle Drive Train

The invention relates to a method for operating a vehicle drive train () comprising a prime mover (), comprising a transmission (), and comprising a driven end (). A friction-locking shift element () is provided, the power transmission capacity of which is variable and, with the aid of which, at least a portion of the torque transmitted in the vehicle drive train () can be transmitted between a transmission output shaft () and an area () of the driven end (). One shift-element half is operatively connected to the transmission output shaft () and the other shift-element half is operatively connected to the area () of the driven end (). The rotational speed of the transmission output shaft () is determined as a function of the rotational speed in the area () of the driven end () and also as a function of the rotational speed of the prime mover () and the ratio currently engaged in the area of the transmission (). In the event of a deviation between the rotational speed of the transmission output shaft () determined on the output end and the rotational speed of the transmission output shaft () determined on the transmission-input end, which is greater than or equal to a threshold value and/or an operating temperature in the area of the friction-locking shift element (), which is greater than or equal to a limiting value, measures reducing loads of the friction-locking shift element () are initiated.