etc in the left column of fig2 are listed and stored preferably in the form of a table or matrix in order to be able to react appropriately when fault symptoms 1 occur it is necessary to determine the causal fault to determine the cause of the fault therefore in addition to the symptoms a 1 u2013 3 b 1 u2013 3 c 1 u2013 3 information is also acquired from a system definition 11 and in some instances also new system states which have come about as a result of the fault reactions the system definition 11 contains for example hardware definitions vehicle variants mechanical components and everything used in the engine or in the vehicle all the information thus obtained is used first by a diagnosis device 10 with reference to its fault profile to determine one or a plurality of actual faults the diagnosis device 10 thereby checks the symptoms a 1 c 3 and uses the fault profile to verify which mechanical physical or electrical symptoms have occurred which risks exist or which consequences can be drawn from the individual symptoms and the further information analysis follows using a diagnosis manager 3 which filters out one or if necessary a plurality of faults collating them and storing them in corresponding fault lists 12 transfer to a fault code a fault confirmation or a generalization of the fault u2014 as in the prior art u2014 is possible but not necessary.