My list of symptoms was all part of this skreem unit. I had a bad battery to start in the car and also bad batteries in key fob. And my key was broke from the fob so I replaced the fob shell got new batteries for the keys and the car. Went through all these forms thinking it was the RCM or other issues. Did the resoldering of the RCM and it would still have the same symptoms. After reading and reading and thinking it was this skreem unit I didn't want to take it all apart and send off to be fixed. So out of a whim I took the new key fob busted it back apart. Put it back in the old fob and tried it.... She fired right up. No issues whatsoever. So I assume some of these fob replacements have the computer chip a little too far back for the key to be read.

Just thought maybe I would throw it out there as something for somebody to try.

 

Yes, there is a tiny RFID chip in the front next to the key. It must be there to run the car. There are U-tube videos on how to replace the FOB that shows how to do it. You are lucky you kept the old FOB.

 

I even put the old RCM that was replaced by the previous owner before I owned it. But it was resoldered.

 

So I really like the more modern looking key fob shells from AliExpress - Black with Silver button, silver "key holder" and the open/close buttons painted on. Plus, you don't have to glue them, there is a screw where the emblem is supposed to go.
I replaced both of my keys and loved the look and how modern they are, because my originals got worn. I also had really nice Chrysler key fob logos made as well as SRT6. Everything worked great till one day my car would start then die....and I had to try it like three times to get it started again and eventually it would.
It wasn't the RCM cause I have a brand new one. It wasn't the CPS because this happened at cold start....I was baffled and thought my 25,000 mile SRT has a skreem issue? I wanted to scream! LOL That is till I realize something rattling inside the key....you guessed it, it was the little black transponder. Some of the replacement shells do not come with the plastic inset that holds the transponder in place and the one from the original key doesn't always work. And that was the issue...the transponder was moving around in the shell. Hard to believe cause I would think whatever sensor is in the ignition, would pick that transponder up even if it slides down a little as long as it's close.
I didn't want to super glue it in place so I used Elmer's Glue because I might want to change the fob case again in the future. And no problems....sometimes it's the simple things we miss....Shame on me, cause on one key I had used a dab of Elmer's on the other one I thought the fob case would hold it in place. Hint: I doesn't LOL

 

Thanks for the info! If I replace my fob I'll use the Elmer's glue to hold it in place.