Finally got mine fixed.
My truck is a 2014 Silverado double cab with the 4.3 V6.
Neither my key fob nor my TPMS would work. I replaced the RCDLR and that didn't work. Followed some wires and didn't see anything broken, so I took it to a good mechanic. They found that there was no power going to the RCDLR, so the first thought was a broken wire somewhere in the wire harness. Normally the fractured wire would be under the door sill where people step to get in and out of trucks - that seems to be where most broken wires are found.
There was no breaks there so they traced the wires to the BCM and there was no power coming through BCM on those pins. Decided to replace the BCM before more things started to fail in it since they only ever fail in one direction. Power was now going from the BCM to the RCDLR, but still wouldn't work.
After a lot more diagnosing and time they finally found that the shark fin antenna had been leaking. That is par for the course on these vehicles, but doesn't normally cause critical issues it seems. There was never any wet spots on the headliner in the cab, so I never noticed that it even had a leak unfortunately.
They found that the leaking water was getting into the connectors and causing issues with power going to and from that particular cluster in the BCM. Those 20 or so wires had corroded badly and were causing incorrect voltages, arcing issues and other problems around the BCM. If the truck was suffering with just a lack of key fob and TPMS I would not have fixed it, because it was a stupid amount of money to spend on an 'accessory'. I would have just replaced the leaking antenna myself and sealed it better. Since I didn't want to cook my new BCM or cause any more damage down the line where the truck may just not start anymore, I asked them to go ahead and fix it.
They basically bypassed the corroded connector X225 near the BCM, replaced the antenna and sealed it better, and replaced/cut back any corroded wires so that they are clean and don't cause any more shorts or arcs.
This fixed the key fob and TPMS issues thank the Lord.
Only took about 10 months and way too much money to figure out, but I hope this saves someone money and time down the line.
