In the 6l80e there is apparently an occasional need to do a "Service Fast Learn Adapts" in order to get the TCM to learn the line pressures, etc. I'm about 90% sure that I need to do this. I have read the procedure via AllData and various hits on Google. Normally, a dealership would do something like this, but it does seem to be an option in HP Tuners as well. Has anyone ever done this?
I know the TCM will provide instructions to HP Tuners that will display instructions on my laptop screen to follow (ex. SHIFT TO D) and I only have 2 seconds to do it.
For each mistake (ex. taking longer than 2 seconds to comply), I have to disconnect the battery for 10+ minutes and start over. This is why I'm looking for "what to expect" if anyone has done this.
[FYI, I moved my TCM into a high performance transmission and have now moved it back to my stock one. No gears (fwd or rev) will engage, so this seems like the easiest thing to try]