Re: weird trans problem help
There is in fact not a big difference when you have your foot on the accelerator, or when you are in cruise mode, its only a different cable which hold the throttle plate in position.
Its the TCM which controls the torque converter clutch engagement, depending on several inputs. I could not find any different input for manual accelerator or cruise. Did you check for any fault codes with the key dance?
Without any fault codes set, i would start cleaning all connectors on transmission, TCM and PCM.
A faulty TPS sensor could cause the torque converter disengagement, but it would not explain it behaving normally in manual mode.