Did some investigation. The sensor is fine. Reads nominal resistance 2.5kOhm at room temp. While I was in there searching for AC condenser leaks and what not I noticed the trans cooler had come out of its bracket and was just hanging out against the frame rail between the radiator ad AC condenser. Oil cooler was also flopping around.

A few years back I got stranded on a road trip couple thousand miles away from home and had to get the radiator replaced. Scumbag mechanic that did it didnt put the damn mounting bolts back in and just left everything loose. Also had a couple broken plastic brackets and the fan shroud was loose. Never going to a mechanic again.

Im going to get everything mounted up properly. Will need to make a custom mount bracket probably. When I remove the quick connect fittings from the coolers will they leak or do they self seal?

 

quick connects very hard to remove, have to push very hard to get retainer to snap back in. Might blow off while driving if not snapped in, if you disconnect pull very hard to test. Factory arrangement is a screw on one end and tab in a slot in the other. I typically drill a hole and use screws on both ends, easier to install and remove radiator that way. Unlikely that the lack of the mounting is causing your overheat trans code.