2003 Chrysler Town and Country limp in mode

I am getting a 700 & 760 codes with my OBDII scanner. I tested the solenoid pack and got 0-1 ohm replaced it & that one had a 2.5 ohm reading. erased the code when done & it came right back. I do not like to throw money at it. Fluid looks great. This is a question you answered 1000x I could replace both input output sensors but if I put a used tcm will it have to flashed. I was let go from my job of 26 years because of my health so dollars is issue . any help would be great