2011 town and country 1st and 2nd gear and reverse working but won't go into 3rd or higher

Presuming no further noise or additional symptoms, it's most likely the notorious solenoid...

Yep a solenoid probably. Any codes that point this out? Generally P0750 - P0765 range. Have you had the fluid changed? Under 100K miles? Be careful about a flush. I would not do it if it is over 100K. Under make sure you change filter also. I have read that dirty fluid causes these solenoids to go out.

Drop and replace fluid is what most do on older transmissions if they are leaking at the pan gasket. And filter replace to catch new sludge from new fluid breaking it up.

The fluids have been replaced along with the filter and gasket. Also the resistance on all 3 solenoid have been checked and the resistance is fine. If we drive it in triptronic 1st 2nd and reverse works , but the second we go to three or fourth it cuts out. No codes are showing.

I would have someone pull historical codes with a level 2 scanner and see if you had any trans codes. A bidirectional scanner will most likely do this like a DS708 computer.

Hook scanner up and put in live data mode on trans functions and have someone review live data as you drive in this mode. These are affordable scanners that do this. These dont have to be dealer level computers.