I have installed a 2019 L83 engine, mated to a 2010 6L80 transmission in my 1988 Silverado. Most things work, even if the TCM including the software is way older that the engine ECM. However, the transmission does not work as it should. Kick down does not work, hard shifting sometimes etc.
When looking at VCM Suite trans engine torque is 1 Nm all the time. The engine torque is present though.
Here is a link to a photo from VCM.
https://www.dropbox.com/s/t75dp1sa3l..._1179.jpg?dl=0
Is trans engine torque the same as engine torque? If so, should the ECM send the engine torque value to the TCM?
Do you see any other issues in the list on the picture?