METHOD AND DEVICE FOR DIAGNOSING COMPONENTS OF AN EXHAUST GAS SYSTEM IN AN ENGINE SYSTEM THAT INCLUDES AN INTERNAL COMBUSTION ENGINE

A method for operating an engine system that includes an internal combustion engine and an exhaust aftertreatment device. The method includes: carrying out a filling control in order to regulate a filling level of the exhaust aftertreatment device as a function of a predefined filling level setpoint value, a lambda setpoint value for a lambda regulation being predefined as a manipulated variable, adapting the filling control with the aid of an adaptation variable that indicates a correction value for the lambda setpoint value, and storing an adaptation value as a function of an operating range of the engine system, the adaptation value in question being updated with the value of the adaptation variable for the instantaneous operating range.