Method for sensing a fuel composition to restrict the usability of a vehicle in the event of a misfueling

A method for CO2 certification and/or CO2-dependent homologation of a vehicle on the basis of at least one design feature of the vehicle which includes an approved use of a CO2-reduced fuel in the vehicle, the method comprising:

• detecting, by at least one fuel sensor arranged in a fuel tank of the vehicle or a fuel feed line that extends between the fuel tank and an internal combustion engine of the vehicle, whether a fuel in the vehicle is a CO2-reduced fuel which is approved for the vehicle or is a non-CO2-reduced fuel which would indicate that a misfueling of the vehicle has occurred;
• and
• displaying at least one error notification to a user of the vehicle, via at least one display element in the vehicle, when the at least one fuel sensor detects that the fuel in the vehicle is the non-CO2-reduced fuel so that a corrective action can be undertaken,
• wherein a specific chemical composition of the fuel is detected by the at least one fuel sensor, wherein a specific chemical composition pattern is created from the specific chemical composition of the fuel and is compared with standard reference composition patterns of CO2-reduced fuels, so that a fuel considered to be CO2-reduced is inferred in the event of a match,
• wherein the at least one error notification that is displayed includes at least a message about the misfueling that has occurred and a corresponding prompt for the corrective action to be undertaken, the corresponding prompt being a prompt to visit the nearest repair shop within a predefinable travel distance,
• wherein after issuing the prompt to visit the nearest repair shop, information is additionally provided in the display element about restrictive actions to occur in the future as a result of the misfuelling,
• wherein the restrictive actions have graduated effectiveness and are initiated to prevent circumvention of the at least one error notification by the user, wherein the restrictive actions, listed in increasing graduated effectiveness, include:
• a limitation of a maximum speed of the vehicle or of a speed of the internal combustion engine;
• and/or
• a reduction in a torque of the internal combustion engine;
• and/or
• a prevention of a predefinable nth engine start (n=predefinable number of remaining permissible engine starts), wherein n=0 is possible so that even one next engine start is prevented, or
• a prevention of a predefinable nth engine start (n=predefinable number of remaining permissible engine starts) in combination with the reaching of a predefined travel distance, wherein only n predefinable engine starts (n=predefinable number of remaining permissible engine starts) is/are permitted once the predefined travel distance is reached, wherein n=0 is possible so that even one next engine start is prevented after the predefined travel distance is reached.