Method and device for error diagnosis in an engine system with variable valve controls

The invention relates to a method for diagnosing the function of one or more variably controllable inlet (8) and/or outlet valves (12) in an internal combustion engine (1); comprising the following steps: - determining a modeled pressure (Pmod) using a pressure profile model, said modeled pressure providing an indication of a pressure in an air system of the internal combustion engine (1), wherein the pressure profile model describes a pressure profile of an error-free internal combustion engine (1) as a function of operating points: providing an indication of the actual, instantaneous pressure (Pman) in the air system; determining a deviation amount as a function of the modeled pressure (Pmod) and the indication of the actual pressure (Pman) in the air system; recognizing an error in the function of the inlet (8) and/or outlet valve (12) as a function of the deviation amount.