Patent ID: 8505367

Claim:
A method for diagnosing an internal combustion engine, in which a cylinder includes a combustion chamber, a fuel quantity and a fresh air quantity being supplied to the combustion chamber for the combustion to generate a torque contribution of the cylinder, which torque contribution is, in a first operating mode of the internal combustion engine, essentially a function of the fresh air quantity supplied, and, in a second operating mode of the internal combustion engine, essentially a function of the fuel quantity supplied, the method comprising: ascertaining a first variable characterizing a smooth running of the internal combustion engine in the first operating mode; ascertaining a second variable characterizing the smooth running of the internal combustion engine in the second operating mode comparing the first variable to the second variable diagnosing the internal combustion engine as a function of the result of the comparison; and recognizing an erroneously supplied fresh air quantity if a third variable, that is a function of the absolute amount of the difference between the first variable and the second variable, is greater than a specified value.