Just a heads up that I have routinely found that P0711 Trans temp sensor code set on my 1995 Ram every time I have plugged in a scanner, which is OBD-I for that last year before OBD-II.

There is not supposed to be a Trans Temp sensor on 1500 Rams, just on 2500/3500 Rams.

I even tried buying a Trans Temp sensor and plugging it into the empty electrical socket, but the code kept getting set.

It may be a factory PCM software error,
a physical 1500 Ram wiring harness fault,
or an evil spirit.