Trouble shooting ECU issue

[Big Bird]

I am having an issue with my truck not wanting to start when it is cold out. symptoms are below say 40-50 degrees the fuel pump will not come on, I get a CAD communications error, I have no gauges, no wait to start light, and I do not hear any relays click when I turn on the key. I have not seen any codes using the key trick. now here is the fun part. If I plug the truck in for a few hours it will start just fine and everything works properly. Truck has new batteries, and the connections are tight. Should I be chasing grounds with these symptoms, or should I be looking for a cold solder in the ECU, or am I just chasing my tail without diagnostic equipment to see what sensors are reading? When it works properly fuel pressure shows 20 idle 17 wot. I am thinking this is a temperature related open in a circuit somewhere as if I warm the block the problem goes away.Apparently my sig is not showing, 2001 ram 2500, 4x4, 5 speed, Raptor 150, Quadzilla adrenaline.any thoughts will be welcome.

[Mopar1973Man]

no wait to start light

ECM is not booting up. So since the ECm is not booting up with software then the CCD network is down because the ECM is brain dead. There will not be any relay to click because there is no software to read sensors and turn on grid heaters or even tell the lift pump to come one. Then if you thing your going to start it... It won't because since there is no software it doesn't know how to fire the VP44 either. So your problem seems to stem from the ECM.

[Big Bird]

ok, Mike, do you have any suggestions as to where I can find a ECM that will work? Closest dodge dealer is over 2 hours away. what has to match up if I get a used ECM? Will it have to be reprogramed for the truck anyways?before I purchase a replacement should I plan on disconnecting the Quad to ensure it is not the problem? I just really hate the idea of throwing money at parts without thinking problems through.

[Mopar1973Man]

Even if you buy a new ECM the truck has to towed to the dealer to have it flashed. Even if you got a used ECM off another truck you still have drag the truck down to the dealer swap the ECM there and have it flashed. This is to make sure the proper software is on the ECM. I've heard stories of people getting away with just mounting on a used ECM but eventually need to be flashed because of other issues.

[SNKEBIT]

I have a 95 2500 with a V-10 that had the same issues. Once it got below 40-45 degrees, it wouldn't let the fuel pump come on. Warm out, start every time.Finally took the gamble and bought a pcm from Dodge, cured the problem.I know, I know, it's not a diesel..............