The engine in all modern vehicles is controlled electronically by an ECU, which is constantly processing formation received from a multitude of sensors. The engine’s fuelling, ignition timing, boost if applicable, torque values, etc, are all calibrated within the ECU code based on the conditions in which the vehicle is being used, its altitude, the quality of the fuel in its tank, and so on. Together with the sensor information the relevant tables, or ‘maps’, are used to keep the engine running at optimal performance – whether it is being asked to deliver high or low output.

ECUs are increasingly complex and every new generation that ECU manufacturers (typically BOSCH, Siemens, Delphi, Magnetti Marelli, Denso and others) produce requires a deeper understanding of the strategy that has been employed.