Tranny electronic expert please

[Tookie]

Had hard 1-2 shift for last 3-4 years, started gradually, but became
pretty much every time it shifted - had a couple of shops try to talk
me into pulling it down, but I didn't think the problem was mechanical.
Was in the dealer a month ago for something else, told them about the
hard shifts, they thought a reflash might help. Did the reflash, been
shifting fine since, so I know the trouble was electronic - but now it's
starting to very occasionally shift hard again, maybe once every day or two.
That's how it started before.
My theory is, there is a sensor just barely bad, (or APP) and it's reporting
false info to the PCM - the PCM is adapting to a driving style I don't have,
and upping line pressures.
I never got a code, and the dealer saw none when it was scanned.
Anyone have an idea what is causing this?

 

[bk95td]

With a scan tool hooked up you can tell what the app is doing. Also input and output signals, commanded pressure,temp and other tranny functions. Without knowing what those readings are you would only be guessing. Autoengineuity scanning software is only $200. Then all you need is a laptop. The stealer charges almost that much for a diagnostic fee.