1. A control device of a hybrid motor vehicle having an internal combustion engine and an electric motor, the control device being configured for controlling the operation of the internal combustion engine and the electric motor of the motor vehicle, wherein when a defined function for diagnosing a condition of the internal combustion engine has not been executed by the control device because a defined operating state of the internal combustion engine has not occurred, the control device determines an operating parameter of the internal combustion engine, and on the basis of the determined operating parameter, the control device, in a temporally variable manner, selects one process from a plurality of processes for influencing the operating state of the internal combustion engine, wherein one of the processes includes changing the relative torques of the internal combustion engine and the electric motor while maintaining a constant drive torque of the hybrid motor vehicle, and the control device carries out the selected process based upon the determined operating parameter in order to facilitate eventual execution of the defined function for the diagnosing the condition of the internal combustion engine.