I am guessing that I have missed something.

[rcmedic]

My 2015 Ram 2500 6.7 Turbo diesel has been awesome. With about 120k miles on it, I returned home from a short 30 mile trip into town. Shut the truck down got out and attempted to lock the doors with my key fob as usual. The doors did not lock. Tried all of the function buttons. No Panic, No lock/unlock and no remote start. Stick the fob into the ignition and the truck starts right up and runs fine. Repeat to process noted above with same result. Try my other three key fobs. Same result with two out of three and one fob just totally dead to include not starting the truck. (new battery in the dead fob changes nothing). Trouble shooting so far nets zero obvious leads. I have several tried several OBDII readers and AlfaOBD as well. I am at a loss. Any feedback or suggestions appreciated.

 

[NJMOPAR]

RF hub crapped out possibly?
Not sure where it's located on your truck, maybe behind the rear seat on the cab wall.

 

[Dean2]

Process of elimination. One FOB works, so you know the tech on the truck is working. Do the two FOBs that don't work have new, TESTED, batteries. Measure them with a volt meter, I have seen them come out dead from the package. The fobs work when you put them in the ignition, so you know they are partly okay. Do they actually transmit a signal, do you have RF interference, as in have you put new LED lights etc in near your truck. If you go to a bare parking lot, do the FOBS work.

After trying all this yourself, only option is to have them actually test the FOBs, the fact one of 4 works means it is likely FOB based if it isn't RF.

 

[18CrewDually]

To the post above, he said NONE of the 3 worked.

OP, my Napa has a FOB tester to test the battery. Its usually near the counter and lights up if it receives a signal when you hit a button. Test them.
They'll probably test fine but worth it to verify and doesn't cost anything.
Since you mentioned AlphaOBD, I'd then attempt to program the 3rd key to the truck. Maybe something glitched and the RFHub lost memory to the programmed fobs. I'll have to check but there may be an RFHub test to see if the module receives a signal. I'll look into that and post back.

 

[18CrewDually]

Ok using AlphaOBD you have some tests you can do to test antennas too. You can also see if it recognizes programmed fobs within the vehicle. To program fobs you will need the 4 digit pin.