Method and control unit for operating a drive train of a vehicle

A method for operating a drive train (1) of a vehicle that includes an electric machine (3), a transmission (5), a starting component (7), and a driven end (6), the transmission (5) connected between the electric machine (3) and the driven end (6), the starting component (7) comprising a friction-locking shift element of the transmission (5) or a transmission-external, friction-locking clutch, the method comprising:

• adapting a predefined charge pressure value for the starting component (7) to be adapted in order to determine an adapted charge pressure value for the starting component (7);
• in order to check a plausibility of the adapted charge pressure value, changing an actuating pressure of the starting component (7) corresponding to the adapted charge pressure value by an offset and ascertaining a change in a torque of the electric machine (3);
• and
• when the change in the torque of the electric machine (3) and the offset of the actuating pressure correspond within defined limits, inferring a plausible adapted charge pressure value, or, when the change in the torque of the electric machine (3) and the offset of the actuating pressure do not correspond within the defined limits, inferring an implausible adapted charge pressure value.