Need 545RFE Help

For the cost of the temp sensor would start with that if I had one doing that again.

But check the grounds to the controller. Mine is mounted on firewall on the passenger side

On my diesel the TPS only sends signal to the transmission for shift points. I have bypassed it altogether and have a potentiometer that I can control the shift points for towing or just the truck. The bad to this is I don't have a kick down, but with the torque of the diesel don't need it very often and I can get it to shift real early without the trailer or with it keep it in longer than if on the TPS. I like keeping the rpm low so early shift is good for me

Your truck is a drive by wire and probably cannot make some of the modes I have to my transmission shift control

What I can say is this drove me NUTS trying to get it fixed.