Driving unit for motor vehicle and method for determining the characteristic of a coupling of the driving unit

A drive unit for a motor vehicle, comprising:

• at least one drive engine with an output shaft;
• a transmission, the transmission having an input shaft and at least one intermediate shaft with an intermediate shaft brake;
• a friction clutch with a first friction element connected to the output shaft and a second friction element connected to the input shaft;
• a clutch operating mechanism for engaging and disengaging the friction clutch;
• an electronic control unit for controlling the clutch operating mechanism in dependence on various control parameters;
• a position detector, the position detector detecting a position of the clutch operating mechanism and transmitting a position-dependent signal to the control unit;
• a torque transmitter, the torque transmitter detecting torque at the input shaft and transmitting a torque-dependent signal to the control unit;
• the control unit being arranged so as, on predetermined occasions, when the transmission is in a neutral position and the intermediate shaft brake is applied, gradually to alter a degree of engagement of the friction clutch and to register and store, as a function of the position of the clutch operating mechanism, the torque measured by the torque transmitter.