The power train of a motor vehicle has an automated clutch which can transmit torque from a prime mover to a transmission in response to signals from an electronic control unit. The latter causes the clutch to transmit a constant torque during a first interval, to thereupon transmit a gently varying torque during a second interval if the operator of the motor vehicle fails to carry out certain necessary operations prior to elapse of the first interval, and to thereafter transmit a pronouncedly varying torque during a third interval if no remedial undertakings were completed during the second interval. The third interval is cut short if the engine tends to choke, and the full or shortened third interval can be followed by a fourth interval corresponding to the first interval or by a further interval corresponding to the second interval.