An arrangement, a computer-readable medium and a method for controlling an HCCI (homogenous charge compression ignition) engine are disclosed. The arrangement comprises a control unit for initiating closure and/or opening of the inlet valve and/or the exhaust valve at a current crankshaft angle in such a way that self-ignition of the fuel mixture occurs when the crankshaft is at a target crankshaft angle. The arrangement comprises cards for storing relevant values of the current crankshaft angle as a function of at least one operation-related parameter such as engine speed, temperature and pressure, and an estimator estimating values of the operation-related parameter during operation of the combustion engine. The control unit can adjust the inlet valve and/or the exhaust valve depending on the stored value of the current crankshaft angle.