Coincidently, I'm having the exact problem with my heretofore problem free 2014 GC Ltd. like yours I plug in the USB cord from my I Phone into the USB port, and what previously worked before, does not work and charges only. The dealer said to use the AUX port instead ! ( then, why did it work previously ?)
I'll call a few other dealers tomorrow and let you know what happens.
I'll bet however, the more knowledgable Jeep Forum members will know exactly the problem and solution.
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