I have a 6L 4L80E swapped vehicle that was brought in for a speedo calibration as it shifted hard and the speedo wasn't calibrated for the gears and tire size.
The engine, trans, harness and computer all from an '03 4x4. The output of the trans was changed to make it a 2WD and the VSS was moved to the trans tailshaft from the TCase.

I didn't do the initial cal for the swap so don't know all that was changed from stock.

Upon calibrating for the gears and tires the VSS was off by about half (GPS showed 50MPH and VSS showed 27). I thought at first it was thinking it was in lo range on TCase and maybe pin 16 was grounded but this is not the case.

I tried to cheat it by offsetting with the speedo calc now the VSS and GPS match but it is shifting at 2x the mph at TPS in the part throttle shift tables ( 1-2 shifts at 39 when it should shift at 19, 2-3 shifts at 40 when it should shift at 19, what a coincidence these are the same value although different TPS).

Any thoughts?
Attached are calibration as pulled and the current cal with log file.
Thanks
Eldon
Mike_28Mar2021__0000.efi
Mike_1965_C10_12582603_Shifts_0.8_28Mar2010_0005.ctz
Mike_1965_C10_12582603_Pull_Cal_27Mar2010.ctz