Patent ID: 8041496

Claim:
A control device for an internal combustion engine comprising a tank venting device, wherein the tank venting device has a fuel vapor reservoir which is connected to a fuel tank of the internal combustion engine in such a manner that fuel vapors escaping from there are delivered to the fuel vapor reservoir, and which is connected to the internal combustion engine in such a manner that during a tank venting operation the fuel vapors contained in the fuel vapor reservoir are delivered to the internal combustion engine as regeneration gas, wherein in order to check the operability of the tank venting device, the control device is operable to: ascertain the fuel concentration in the regeneration gas at a minimum of two different points in time during the tank venting operation, compare the values ascertained for the fuel concentration in the regeneration gas with reference values assigned in each case, wherein the reference values represent the fuel concentration in the regeneration gas for the situation in which no additional fuel vapors are delivered to the fuel vapor reservoir during the tank venting operation, and to carry out an assessment of the operability of the tank venting device is carried out on the basis of the comparison of the values ascertained for the fuel concentration in the regeneration gas with the reference values.