tpms troubleshooting

I have a 2010 Nitro. The tpms indicates the monitor for the left rear is not working so I switched the rear wheels so that side had a known good sensor, and the left rear still has no signal. So I checked for a trigger for that wheel. I found out there are 3 triggers on the car and it uses...

I hope no one has asked this already. Everytime i search for any thing here, there are hardly ever any results. Is there another Mopar forum or Minivan forum that has more activity? My question is about the TPMS sensors and how to determine which one is triggering the ding. It is driving me...