KESS v2 is extremely sensitive to voltage ripple. If your battery charger drops below 13.2v or surges above 14.8v during the write process, the checksum calculation fails.
If you are working with a master or slave tool and encounter the dreaded "Checksum Error Writing Buffer" message, you aren't alone. This specific error typically triggers during the final stages of the writing process, preventing the modified file from being successfully flashed to the ECU. checksum error writing buffer kess v2 verified
[SOLVED] Checksum error writing buffer Kess V2 (Verified Fix) KESS v2 is extremely sensitive to voltage ripple