A method for operating a motor vehicle having a first drive machine that is an internal combustion engine and a second drive machine that is an electric machine, the method comprising:
- controlling the first drive machine and the second drive machine in at least a normal operation mode and a fault operation mode of the motor vehicle such that the first drive machine propels the motor vehicle, while the second drive machine operates as a generator and increases a load of the first drive machine by an amount of increase;
- and
- switching between controlling the first drive machine and the second drive machine in the normal operation mode and controlling the first drive machine and the second drive machine in the fault operation mode based on a number of wheel revolutions of at least one wheel of the motor vehicle that is detected by a wheel revolution sensor of the motor vehicle,
- wherein, in the normal operation mode, the controlling controls the second drive machine such that the amount of increase of the load of the first drive machine does not exceed a first limit value and a motor slip control of the motor vehicle is performed applying additional torques to the second drive machine or reducing negative torques of the second drive machine to prevent destabilization of the motor vehicle,
- wherein, in the fault operation mode, the controlling controls the second drive machine such that the amount of increase of the load of the first drive machine does not exceed a second limit value that is smaller than the first limit value, and the motor slip control of the motor vehicle is not performed,
- wherein the first limit value is chosen such that, when a driving torque of the first drive machine is reduced to zero, while the amount of increase is set at the first limit value and at a same time a motor slip control of the motor vehicle is performed, destabilization of the motor vehicle occurs in a first test driving situation corresponding to the motor vehicle being driven on a wet roadway and no destabilization of the motor vehicle occurs in a second test driving situation corresponding to the motor vehicle being driven on a dry roadway, and
- wherein the second limit value is chosen such that, when the driving torque of the first drive machine is reduced to zero, while the amount of increase is set at the second limit value and at the same time the motor slip control of the motor vehicle is not performed, no destabilization of the motor vehicle occurs in the first test driving situation corresponding to the motor vehicle being driven on the wet roadway.