This was a major addition for diesel specialists, providing support for 6.7L Power Stroke V8 engines utilizing Bosch EDC17CP05 and EDC17CP65 ECUs. It enables reliable reading, writing, and checksum (CK) correction for Ford trucks across several hardware variants (BC3A, FC3A, and HC3A).
During installation, when prompted, install the FTDI and USB drivers. Even if you think you have them, install them again. The 121 update uses updated driver signatures. pcmflash 121 upd