There's not much need to talk to your transmission tech since it's tuning related and not due to the transmission build.
Torque converter clutch apply is dictated by accelerator pedal position and road speed. With the 99-03 trucks, there is a bit of "adaptive" finagling that the PCM does (unlike the 95-97 trucks that do exactly what we want them to do right when told to do so).
In your particular 80T program, the way the torque converter apply is commanded in the tuning, the lowest speed we should expect apply would be about 35-36 MPH. At an accelerator pedal position voltage of 1.23, the speed begins to increase sharply and at 1.96 volts the torque converter apply speed becomes about 42 MPH. At 2.0 volts, the speed at which the command is initiated becomes lower (about 35 MPH again) while the speed increases gradually to 39 MPH at 2.8 volts and remains 39 MPH until the APP voltage is maxed out.
Do you see any of the voltages you gave me line up with any that I gave you? It just so happens that the ranges you gave lie right about in line with where the vehicle speed increases before torque converter clutch apply.
My money says that flat-lining the TCC apply command at 36 MPH and then setting a time delay for 4-5 seconds in addition to lowering the TCC release speed to 31 MPH across the board would work out pretty well for you.
However, while typing this out, I'm not certain about this because I don't deal with TNAA7S3 unless someone happens to have it while using a programmer. With the Phoenix chips, we'd use a modified hybrid VDH2/PMT1 strategy that allows TCC apply whenever it's commanded and a lot of the 02-03 trucks have really weird operational characteristics that don't allow torque converter clutch engagement under certain operating conditions (for whatever reason....stupid engineers I guess). However, with a programmer, we can't put that particular VDH2 program on a VDH5 computer; it just won't work.
I can try a couple tricks in the tune and have Bill put it on Fusion for you. However, I'm not certain that I can make the PCM do what I want.....I know how to do it (my personal 2000 is that way) but if yours will is a completely different story.
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