I had this problem back in February with my 2012, except mine would not shift past 2nd gear or manual shift at all. Mine would not throw a code on the cluster but hooked up an OBDII scanner and it was throwing P0730. Took to the dealer and they told me it was the shifter itself and not covered under the powertrain warranty $500 parts and labor. They install and still doing the same thing so they tear into the transmission (covered under powertrain) for complete rebuild, Jeep only had 48k miles at this point mostly highway driving with the occasional wheeling on easy stuff. Well that did not fix it so they replaced the TCM under warranty, still no go. They call and start asking about if jeep was re-geared and if it had a programmer and they were about to call Fiat/Chrysler for what to do next, I told them to look at the notes in the computer and tell me what the notes say the day I dropped it off, "Jeep has a programmer for the re-gear and tire size correction".
Just be sure that if they replace anything electronic, be sure to tell to reprogram with your programmer, I could have had my jeep back 2 months earlier had they just reprogrammed with my Flashpaq after they replaced the shifter. I am not complaining the least little bit, I only came out of pocket for the initial shifter issue. The tech and service manager did not think that the programmer had anything to do with the electronic shifter or the TCM, only the PCM.
Good luck with the outcome.