Abstract: A method for operating a start and entry system of a motor vehicle, including the steps of: detecting whether an authorization of the starting of the motor vehicle is carried out on the basis of a key signal received on the vehicle side, which has been sent from a transmitting and receiving unit of a vehicle key, or whether the authorization of the starting of the vehicle is carried out on the basis of a near-field signal received on the vehicle side, which has been sent by a near-field communication system of a mobile communication device. If the authorization of the vehicle start is carried out on the basis of the key signal received on the vehicle side: the start and entry system is operated in a key operating mode, in which, following the starting of the vehicle, only the availability of the vehicle key in a vehicle interior of the motor vehicle is monitored.

Abstract: A method for operating an anti-theft device for a motor vehicle which is unlocked when a radio signal is received from a radio-based remote control device of the motor vehicle and, after unlocking, is started by actuating a start/stop operating element. Here, an interior of the motor vehicle is monitored by a detection device of the anti-theft device after the motor vehicle has been started. For the monitoring of the interior of the motor vehicle, a search signal restricted to the interior is output by the detection device in the interior of the motor vehicle. The radio-based remote control device is configured to output a detection signal when the search signal is received. If the detection signal is not received by the detection device before a predetermined search time, a warning message is output to a unit outside the vehicle.

Abstract: A method for operating an anti-theft device for a motor vehicle which is unlocked when a radio signal is received from a radio-based remote control device of the motor vehicle and, after unlocking, is started by actuating a start/stop operating element. Here, an interior of the motor vehicle is monitored by a detection device of the anti-theft device after the motor vehicle has been started. For the monitoring of the interior of the motor vehicle, a search signal restricted to the interior is output by the detection device in the interior of the motor vehicle. The radio-based remote control device is configured to output a detection signal when the search signal is received. If the detection signal is not received by the detection device before a predetermined search time, a warning message is output to a unit outside the vehicle.

Abstract: A method for operating a start and entry system of a motor vehicle, including the steps of: detecting whether an authorization of the starting of the motor vehicle is carried out on the basis of a key signal received on the vehicle side, which has been sent from a transmitting and receiving unit of a vehicle key, or whether the authorization of the starting of the vehicle is carried out on the basis of a near-field signal received on the vehicle side, which has been sent by a near-field communication system of a mobile communication device. If the authorization of the vehicle start is carried out on the basis of the key signal received on the vehicle side: the start and entry system is operated in a key operating mode, in which, following the starting of the vehicle, only the availability of the vehicle key in a vehicle interior of the motor vehicle is monitored.

Abstract: A locking device for a motor vehicle. A transmitting device, which is designed to send out a request signal into a surroundings of the motor vehicle in dependence on a predetermined triggering event, as well as a receiving device, which is designed to receive, within a predetermined time interval from the sending of the request signal in a predetermined frequency region, a response signal of a radio key from the surroundings, and a control device, which is designed, in event of a response signal received within the time interval, to unlock at least one lock of the locking device. An evaluation module is designed so that the transmitting device sends out an interference radio signal after the sending of the request signal within the time interval at least at one radio frequency lying outside the frequency region.

Abstract: A locking device for a motor vehicle. A transmitting device, which is designed to send out a request signal into a surroundings of the motor vehicle in dependence on a predetermined triggering event, as well as a receiving device, which is designed to receive, within a predetermined time interval from the sending of the request signal in a predetermined frequency region, a response signal of a radio key from the surroundings, and a control device, which is designed, in event of a response signal received within the time interval, to unlock at least one lock of the locking device. An evaluation module is designed so that the transmitting device sends out an interference radio signal after the sending of the request signal within the time interval at least at one radio frequency lying outside the frequency region.