Motor vehicle, in particular utility vehicle, having at least one control unit, wherein at least one driver assistance system is implemented in a program-assisted fashion on the control unit, wherein said at least one driver assistance system uses distance data and/or speed data of a radar sensor which the control unit receives from the radar sensor which is connected thereto, and wherein the control unit uses the motor vehicle's own speed to change the switched state of the radar sensor, characterized in that, in order to minimize the switch-on times of at least the transmitter unit of the radar sensor, the control unit cyclically receives further state data of the motor vehicle via encoders which are directly or indirectly connected to said control unit, and holds said data, and conditions according to which the switched state "radar sensor active" or "radar sensor inactive" is maintained or brought about are predefined with respect to the state data in the control unit, and in a first routine the state data are determined cyclically and held, and in a second routine there is continuous checking as to which of the predefined conditions are met, and the associated switched state of the radar sensor is then maintained or brought about, and wherein in its inactive state the radar sensor does not emit any radar beams, in that the state data comprises the activation state of the parking brake, the activation state of the service brake, the execution state of the at least one driver assistance system, the accelerator pedal position, the operating state of the engine, the motor vehicle's own speed and the presence of a diagnostic command for the radar sensor or the at least one driver assistance system which uses the radar sensor, and in that the control unit cyclically runs through, in a program-assisted fashion, a control sequence, in which, when - the parking brake is activated and/or - the service brake is activated and at the same time the vehicle's own speed is zero and/or - the at least one driver assistance system exhibits an active fault and the state of the radar sensor is inactive, said control unit leaves said radar sensor inactive, and when the state of the radar sensor is active it switches from its active state into its inactive state, and in that when - at least one driver assistance system is active and also remains active in the stationary state and/or - an emergency brake system is provided and an emergency braking operation has been triggered by a driver assistance system and the vehicle is not in a state which is monitored by the driver and in which the service brake is not activated and/or in which the parking brake is not actuated, and/or in which the driver assistance system which triggers the emergency braking operation is still active despite the motor vehicle being in a stationary state, the control device leaves the radar sensor in its active state even if the motor vehicle is in the stationary state, and in that when - the accelerator pedal is activated and/or neither the parking brake nor the service brake is activated and the motor vehicle's own speed is higher than 0 km/h and when the drive motor of the motor vehicle is running or - a diagnostic command relating to the checking of the at least one driver assistance system and/or of the radar sensor is present and the state of the radar sensor is active, said control unit leaves said radar sensor active, and when the state of the radar sensor is inactive it switches said radar sensor into its active state, and in that the radar sensor does not emit any radar beams in its inactive state. - the parking brake is activated and/or - the service brake is activated and at the same time the vehicle's own speed is zero and/or - the at least one driver assistance system exhibits an active fault and the state of the radar sensor is inactive, said control unit leaves said radar sensor inactive, and when the state of the radar sensor is active it switches from its active state into its inactive state, and in that when - at least one driver assistance system is active and also remains active in the stationary state and/or - an emergency brake system is provided and an emergency braking operation has been triggered by a driver assistance system and the vehicle is not in a state which is monitored by the driver and in which the service brake is not activated and/or in which the parking brake is not actuated, and/or in which the driver assistance system which triggers the emergency braking operation is still active despite the motor vehicle being in a stationary state, the control device leaves the radar sensor in its active state even if the motor vehicle is in the stationary state, and in that when - the accelerator pedal is activated and/or neither the parking brake nor the service brake is activated and the motor vehicle's own speed is higher than 0 km/h and when the drive motor of the motor vehicle is running or - a diagnostic command relating to the checking of the at least one driver assistance system and/or of the radar sensor is present and the state of the radar sensor is active, said control unit leaves said radar sensor active, and when the state of the radar sensor is inactive it switches said radar sensor into its active state, and in that the radar sensor does not emit any radar beams in its inactive state.