After my recent experiences and discoveries with the loveable slush box we know as the AW55-50/51SN, I thought I would jot them all down for those either having similar issues but finding no joy, or those facing similar issues and wondering what to do. I searched MVS for a deeper explanation for this oft overlooked and somewhat complicated tool to help with big transmission issues but couldn’t find anything that really told just how amazing the change that VIDA and this procedure can be! Now… without further adieu…
Let me, before I start into what I did, explain what the difference between the two types of “calibrations” that the AW55-50SN can do. You have a Control Module Adaptation (CMA) and you have a Reset the Adaptation (RA).
The CMA is akin to writing new lines on a blank piece of paper. The TCM (Transmission Control Module) knows about where the lines should be and by going through a series of controlled shifts, it writes the lines that the trans will follow. When you do something big to the trans like a new/rebuilt Valve Body, new/rebuilt Linear Solenoids or even replace leaking internal gaskets, you should do a CMA since the “lines” will now be different to the TCM.
The RA is like a school text book where someone took notes in it. You can read the book, but off to the side, you get the answers the teacher really wants and you get an “A” in the class thanks to Bob, Class of ’62! The TCM is always learning and taking notes. Those notes are great for the current set up, but they need to be erased and start over when you do something simple like change the fluid. Resetting the learning back to a known set of good values.