The definition version is an internal system which details the layout of the memory of the ECU. For example, a very old firmware may not have certain functions or tables, and the definition would have these areas omitted. If you try and load a calibration that is from a different definition type (i.e it was from a different firmware version) MEITE will inform you, and, where possible will text match entities to try to port data across, though this should always be checked after.


When you perform a firmware update, the definition data which is also stored in the *.MEFW file is also extracted and placed into the MEITEs dataset on the PC.