An electronic control unit for an internal combustion engine having a fuel injection system and an ignition system including: timing determination means (2) for determining timing sequences for injection events of the fuel injection system and ignition events of the ignition system and to provide update timing sequence data (10) to a schedule sequencing means (3) adapted to control at least one driver circuit (4) wherein the at least one driver circuit (4) is adapted to provide drive pulses (11) to the fuel injection system and ignition system; wherein the schedule sequencing means (3) is adapted to select between update sequence data to at least one of an injection of ignition event, such that the update timing sequence data is selected when there is no current injection occurring.