ECM failure?

[acfreema]

About a month ago, my 2003 diesel 5.9 stopped running while I was on the highway. All cabin electronics work, engine cranks, but won't start, and push-starting doesn't work. I replaced the fuel filter on the side of the road, but it still wouldn't start. After getting towed to a fairly competent shop, the thing ran fine each time they looked at it. Finally, after a couple weeks, I was going to get the truck, and that day, it wouldn't start. Finally! A week later, according to the dudes at the shop, the problem is probably the ECM.

I asked about connectivity, and harness issues, but those all (reportedly) look and feel fine. Any other ideas? Any recommendations on where I might be able to find an ECM for a manual transmission 2003 diesel ram 3500?

To the best of my knowledge (I think I'm the third owner), everything is stock, except: the turbo was replaced (it looks like another stock turbo), and the exhaust has no cat. Except for a water pump failure this winter, it has run almost 40k miles for me without a problem.

Edit: Noteworthy point? When I got this truck in 2019, it would not start if the coolant temperature was below ~60F. After a lot of fairly heavy towing up and down the mountains, that problem went away, and it would start down around 30F without much extra cranking. Could that starting issue have been a presentation of an ECM problem?

 

[acfreema]

I found a few ECMs from 2003 diesels, but I am unfamiliar with how this vehicle may respond to using a different vehicle ECM. A lot of the ECMs say they're from automatics, but does that matter if it is reprogrammed?

 

[jws123]

Have you scanned the truck any codes? with most vehicles the PCM is almost never the issue not saying its impossible but it sounds like ya need to find a diff shop to look it over It could for sure just be a fuel issue hard to say you need to find someone in your area that works on diesels.

 

[acfreema]

Well, this place only works on diesels, so I am reasonably certain they're not totally incompetent. The last time I had my truck there was in the winter when my compression pump failed, and a previous mechanic at another truck shop thought the issue was the switch or solenoid (Which, in hind-sight, could have been the cause, if the compression pump had been creating pressure correctly.).

The big gamble with this situation is driving the truck has already proven to be risky. Now, at the risk of sounding whiny: Because I live 45 minutes from the shop, getting anywhere else could cost a few hundred dollars for another tow, plus a couple wasted hours for me, and a couple wasted hours for my wife, if it stops while in transit. Sadly, the only other non-dealer places who do diesel work in Lewiston or Clarkston (unless I just can't find the shop.) are big-rig-only, or back-logged for months (like everywhere!).