TPMS C1504 trouble

[KS Ram 09]

The other day the TPMS light started flashing and eventually went solid. It flashes for about a minute after startup and then stays on. Everything that i have read says that that means that there is a system fault not an under/over inflation issue. I took it to a local tire shop and they were able to communicate with the sensor in every tire but they didn't have advanced enough tools to diagnose it any further. I took it to a shop that was able to read a C1504 dtc code. That code says the tpms system is unable to communicate with tire 4. I had the tire shop replace the senser in the left tire hoping that the battery was getting weak and was able to be picked up by the tire shops tool but not the vehicle. No such luck, the light is still on. The tire shop is telling me there should be an antenna for each wheel and that may be my problem but i cant find any info on these antennas. I could live without the system but the light on the dash gets under my skin. Any ideas or info on how to remedy this would be greatly appreciated.

Thanks

 

[KS Ram 09]

Dont know if this will help anyone else but the sensor that was replaced was a rubber stem sensor. The light went out after a tire rotation.