Method and device for determining the icing status of a component of the exhaust gas system of a motor vehicle that is not arranged directly in the exhaust gas mass flow

A method for determining an icing condition of a sensor of an exhaust-gas system of a motor vehicle that is not arranged directly in an exhaust-gas mass flow, and/or of a feed line of the sensor, the method comprising:

• determining, at an engine control unit of the motor vehicle, a water quantity actually present in the sensor and in the feed line thereof and a state of aggregation of the water quantity;
• determining, at the engine control unit, an energy quantity required for deicing and for volatilizing the water quantity actually present in the sensor and in the feed line thereof;
• determining, at the engine control unit, an energy quantity supplied for deicing and for volatilizing the water quantity actually present in the sensor and in the feed line thereof by radiated heat from components arranged directly in the exhaust-gas mass flow of the exhaust-gas system of the motor vehicle to surroundings;
• determining, at the engine control unit, the icing condition of the sensor by comparing the energy quantity supplied for deicing and for volatilization with the energy quantity required for deicing and for volatilization;
• controlling, at the engine control unit, based on the determination of the icing condition of the sensor, the operation state of the motor vehicle, wherein controlling the operation state of the motor vehicle further includes suppressing, an output of erroneous control signals based on the icing condition of the sensor, where the erroneous control signals are indicative of icing of the sensor.