Perhaps a better way to go about this is to get a full read as I know your goal is to defeat the immobilizer eventually. PCMflash can read al551 in boot mode and afaik, these are full reads. I saw some people posting full flash and dflash reads in "Module 82" pcmflash forum thread.

Thanks for reply ! No i don’t look at defeat immo, im offering a flashing utility with XCP logging and XDF definition. Their is a VR systems that can give stock calibration to the user to download. Everything is cloud based (AWS) i already support bunch of VW transmission. Like DQ250/DQ381/DQ500/AL552/DL501G2/DL800. I got the decompression it was a 2047 sliding insteed of the conventional 1023. But until now i have no success in making the compression back. If someone have some piece of code, im interested in ! Let me know and thanks for the reply ! Hopefully supporting AL551 very soon ! Flashing using a ODX just works fine.