Patent ID: 7835849

Claim:
A method for operating an internal combustion engine with at least one cylinder with a combustion chamber, an injection valve which is designed for metering fuel, with a lambda controller being provided in which: a respective lambda adaptation value (LAM_AD) assigned to a respective temperature range is adapted as a function of at least one corrective signal proportion (SGA) of the lambda controller in relation to a control parameter (LAM_RP) of the lambda controller if a respective predetermined condition is fulfilled, which requires that a quasi-stationary operating state is present and the respective temperature range is adopted, with the respective lambda adaptation value (LAM_AD) being assigned to a respective reference temperature in the respective temperature range, a fuel mass (MFF) m to be metered is determined as a function of at least one operating variable (BG) of the internal combustion engine, the fuel mass (MFF) to be metered is corrected as a function of the respective lambda adaptation value (LAM_AD) assigned to the current temperature, and if a predetermined test condition (P_COND) is fulfilled: a check is performed as to which of a number of lambda adaptation values (LAM_AD) was adapted as a function of the at least one corrective signal proportion since the test condition (P_COND) was last fulfilled, a respective lambda adaptation value (LAM_AD) not adapted as a function of the at least one corrective signal proportion (SGA), which in relation to a respective assigned temperature range is adjacent to a respective lambda adaptation value (LAM_AD) adapted as a function of the at least one corrective signal proportion (SGA), is checked as to whether it lies in a range of valid values which diverges in a predetermined manner in relation to the reference temperature of the respective adjacent adapted lambda adaptation value (LAM_AD) starting from the respective adapted lambda adaptation value, and if it lies outside the predetermined diverging range of valid values, the non-adapted lambda adaptation value (LAM_AD) is adapted so that it lies approximately at the closest boundary of the range of valid values in relation to its value before the adaptation.