A process for operating a power train of a vehicle, during an activated internal combustion engine (2) start/stop function. The power train includes the engine (2), which is started with torque from a starter (3), an output (5), and a non-positive shifting element (6A), having a continuously variable transmission, and a starting device (6) arranged between the engine (2) and the output (5). A portion of the torque from the engine (2) and/or the starter (3), depending on a set shifting element (6A) transmission capacity, is directed by starting device (6) toward the output (5). When there is a demand for starting the engine (2), the shifting element (6A) transmission capacity is adjusted to an amount at which at least a portion of the torque, generated by the starter (3), exceeding the needed torque to start the engine (2) during the startup procedure, is directed to the output (5).