The gas gauge most likely is worked by the cluster. And the cluster should get a message over the BUSS to tell the cluster where to set the gas gauge. I don't remember off the top of my head if the body controller or PCM or the cluster itself moniters the sending unit. But all the newer Mopars since around 2000 or so work that way where the cluster just gets a message over the cars BUSS (communication system) from the controller that moniters the fuel tank sending unit and then the cluster positions the gas gauge where it needs to be. Any dealer should be able to work the gas gauge with the scanner to see if the gauge itself is bad and the dealer should also be able to read the controller to see what the sending unit is reading. The dealer can actually command the cluster to work the gas gauge with the scanner and read what the sending unit reads. I retired in 2011 so I have been away from the cars for a bit but you should either have a dealer or find a shop that has the scanner setup to check the gas gauge system. That much better then guessing and throwing parts at it. Ron