I'm lost and need help figuring out what is going on. I have a 03 dodge ram 1500 4wd 5.9 gas engine. It ran perfect and the one day I was driving and the trans temp light and o/d off light comes on and off. It kept doing that for a few months. About a month ago I was driving and the gauges started dropping all the way down and then came right back on and kept doing it for a while. I let it sit for a few days and now it starts and runs perfect until the truck completely warms up and then the check engine light starts coming on and right back off and keeps doing it for about a minute and then the gauges only start to drop like they lost power and come back on and keep doing this for a few minutes and then the gauges stay off and the truck starts idling Ruff and stalls out and won't start back up until it cools down a little bit. I have already replaced the cluster and had it programmed to my Vin Aldo replaced the tipm but not the fcm and I'm still stuck with the same problem doing the same exact thing. Also note codes with the scanner but getting cluster codes AA fcm message not received and AD pcm message not received. The truck only has 135k but it is a 03.

No when I hook up my scanner it says no communication. But when I am able to start it my scanner don't read any codes at all. Only codes I get are the c codes on the cluster. That is what I'm not getting. The other day I did get a code saying throttle pedal position sensor circuit A low and another code saying governor pressure sensor solenoid low. But that's the only codes I've ever gotten and when I started the truck the next day the tps code and the GPS code were both gone and never came back.

that is what I was thinking. I'm waiting for the new ecm to get in so I can replace it. I'm wondering what else is the problem cause I just replaced it with a remanufactured ecm in 2015.

Also on the computer codes it says ecm message not received for 12 key cycles and fcm message not received for 101 key cycles. Is it possible that the fcm is bad also? And I replaced the tipm and used my old fcm do you have to have the tipm programmed or is it just the fcm that has to be programmed?