Calterm CM2450

[APC]

the CRC function in Calterm does not properly calculate the checksum for that ECM... it is a different checksum the BHQ ECMs use, something done by Chrysler, not by Cummins...

once you convert it into intel-hex, you still need to rebuild the 6th block of data that is missing in order for it to be a complete program.

also keep in mind, you'll need to recalculate the Digital Signature of the entire file as well, both RSA/Checksum and Digital Signature need to be properly dealt with in order for the ECM to accept any modified file or anything other than completely stock file. so much as changing the speed limit and sending back in will trip out both the checksum and the digital signature, and fail the program at 100%...

FYI: Rawze has written some software that can reconstruct the missing block(s), etc. once it has been copied out and converted to binary format. It can get around some of these the check-summing issues too. If your doing that kind of ECM work, you should likely go onto his mumble server with those kinds of discussions instead.
mumble> http://rawze.com/forums/showthread.php?t...63#pid2163