Hi guys, you've probably had to read the BCM's EEPROM at some point and edited some values, and when you programmed it, you likely encountered a checksum error in DPS, similar to the "get controller information" error, right?
Well, the BCM's EEPROM has checksum checks throughout the file using checksum-16.

Calculating it is simple. The EEPROM is divided into 64-byte blocks where 00-01 would be the checksum, and 02-64 the data. This data includes the PIN, VIN, odometer, programmed keys, etc.

If you edit something, select the 62 bytes, and in HXD (it should be similar in the Neo hex editor) calculate the checksum-16.

Now, go to the Windows calculator, perform a NOT operation on the value (in this case NOT 1E57),

invert the result, and that's it.

You now have the checksum.

I have some doubts about the last block, because it seems to use a different method or isn't checked, so if anyone can provide information, please let us know. I'll continue analyzing several EEPROMs, but this information seems good.

GL friends

Although the blocks are 64 bytes, the size for calculation is determined in position 02 of each 64-byte block. If calculate with all block you get wrong value:


31 byte selection: