An arrangement for a combustion engine with a control system for determining the engine's crankshaft position includes two independent sensors (S1, S2), each of which cooperates with a group of rotational position markings (r). The two sensors (S1, S2) are crankshaft sensors and they are mutually displaced (a/A) in the rotation direction relative to the midpoints of the relating respective rotational position markings so that during crankshaft rotation the direction of rotation can be determined by comparison of the sensor signal sequences from the two sensors.