Patent ID: 8839604

Claim:
A method for operating an internal combustion engine having at least one cylinder, to which an injection valve for metering in fuel is assigned, with an exhaust tract, in which an exhaust gas catalytic converter is disposed, a first exhaust gas probe which is disposed upstream of or in the exhaust gas catalytic converter and a second exhaust gas probe which is disposed downstream of the exhaust gas catalytic converter, a lambda control, and a trim regulation, the method comprising: determining a controlled variable of the lambda control as a function of a measuring signal from the first exhaust gas probe wherein an actuating variable of the lambda control acts on a fuel mass to be metered in by means of the injection valve, determining a controlled variable of the trim regulation as a function of a measuring signal from the second exhaust gas probe and determining a first trim actuating variable of the trim regulation as a function of a P regulator component of the trim regulation and a second trim actuating variable of the trim regulation as a function of an I regulator component of the trim regulation, wherein in a first mode when a first threshold is exceeded by the first trim actuating variable, the second trim actuating variable is compulsorily adjusted, wherein when the first trim actuating variable drops below a second threshold, which is smaller than the first threshold, a switch is made to a second mode, in which the regulator amplification factors of the second trim actuating variable are increased, and wherein when the first trim actuating variable drops below a third threshold, the amount of which is smaller than the first and second thresholds, a switch is made from the second mode and the calculation of the second trim actuating variable is carried out in a regular manner.