Checksum — bration checksum

A cryptographic or arithmetic sum stored in the ECU bin that the bootloader validates before running the calibration. Bosch EDC17/MED17 use multi-block CRC32 with a header table. Delphi uses a trailing 32-bit sum. Siemens uses a multi-page hash.

Edit a calibration and forget to recompute the checksum → ECU refuses the flash or bricks itself on next boot. Every tuning tool worth its salt auto-recomputes the checksum. Softechpro identifies the format from the bin and rewrites the correct checksum.