Method in connection with engine control

Method in connection with engine control, wherein a combustion feedback signal (2) is derived by measuring in real time in a combustion chamber one or more combustion related parameters during a chosen time period of a first combustion cycle, for control of a possible fault, wherein at least one reference feature for said parameters has been determined previously, and comparing said measured combustion feed back signal with said reference feature for automatic adaptation of at least one combustion related variable during a forthcoming combustion cycle

• characterised in that at least one reference feature for each one of at least two different fault situations having been determined previously, and that a diagnosis (3) of said first combustion cycle is performed on the basis of said combustion feedback signal being processed and compared (T1-Tn) with each one of said reference features, the result of which is analysed by a decision logic, where after a diagnosis (D) is established that decides which fault is to be prioritized by means of which one or more variables in a forthcoming combustion cycle is/are regulated in dependence of the outcome (D) of said diagnosis, thereby achieving fault tolerant engine control.