Hello and welcome to just answer Chrysler. There could be a number of things causing this. A sensor problem,evap leak, loose gas cap, etc. Try this for me: Sit in the vehicle with the door closed, cycle the ignition key on and off 3 times (on/off/on/off/on) do not crank the engine, and do this fairly quickly. Then look at the odometer display and see if a "P" code is displayed. If so, tell me what the code is.
Hmmm, that tells me that there is no actual code. Ok, you will need to get a scan tool connected to the PT and see if it will read any codes. Your local auto parts store will usually connect their scan tool for free and check this for you. If there is a code, let me know. If there is no code, then your PCM (engine computer) may need a software update which can be done at the dealership.