AFM with 8l90

Hey everyone. New to the forum. I bought a 2018 sierra with the 8l90 and t87a TCM. My shop told me when I took it to get the AFM disabled that they would have to ship the TCM off to HP tuners to get it reprogrammed. I don?t see why the afm disable would have anything to do with the trans tune. Please provide some insight and explanation before I fork over an extra $350 for a trans tune that I may not need.i know that the Ecm and Tcm communicate on the high speed can line but I don?t see why a parameter change would warrant a tcm reprogram. Thanks!

https://forum.hptuners.com/showthrea...do-Dod-disable