Patent ID: 8200415

Claim:
A method for controlling the operating mode of an internal combustion engine ( 1 ) with n cylinders ( 3 ) and an injection system ( 4 ) with an injection unit ( 5 ) per cylinder ( 3 ), with the steps: a) determination of a digital measuring signal which characterizes the combustion of fuel ( 6 ) in the internal combustion engine ( 1 ), b) transformation of the digital measuring signal into a frequency range, c) evaluation of the transformed measuring signal, a misfiring of the ignition being detected using the amplitude information of the transformed measuring signal, and if a misfiring of the ignition is detected e) sequential deactivation of the injection of each individual of the n cylinders ( 3 ) for a predefined time, and repetition of the steps a) to c) for each of the n cylinders ( 3 ), wherein using the amplitude information n/2 nd order of the transformed measuring signal a misfiring cylinder ( 3 ) is identified.