What fixed your problem, having this same issue with mine, thinking it might be programing

 

3rd gear is most likely mechanical failure.
We had this problem and the only thing that fixed it was a new transmission.

 

I have similar problem limp mode and won't shift up from third. I have the superchips flashpaq and this happened immediately after I went from the trail which had mud, hard flex and water to the payment.. Prior I had absolutely no problem signs or symptoms.. Codes started with p0730 so I thought maybe something with the tuning so I tuned it back to stock then retuned. Then p0733 code comes up.. I'm lost..