Battery Short randomly losing ECM power w/ign on

[Rawze]

(09-03-2019 )Gump12b Wrote:  ...
I was very tempted to remove the inline fuses
...

If there is a wire connected directly to the batteries -- IT MUST BE FUSED! - NEVER EVER BYPASS FUSES!!! - ONE DAY YOU WILL REGRET IT GREATLY!!! while you watch your truck burn to the ground.

REPLACE the fuse holder and fuse if it is suspect,.. but NEVER BYPASS THEM!

[Lonestar10]

i went through 3 cummins reman ECMs before i got one that worked.

[tree98]

(09-04-2019 )Lonestar10 Wrote:  i went through 3 cummins reman ECMs before i got one that worked.

How do you prove to the dealer that it was bad out of the box? Or do you just eat the cost and buy another?

[Rawze]

(09-04-2019 )tree98 Wrote:  

(09-04-2019 )Lonestar10 Wrote:  i went through 3 cummins reman ECMs before i got one that worked.

How do you prove to the dealer that it was bad out of the box? Or do you just eat the cost and buy another?

Whenever you buy an ecm,.. ALWAYS have the stealers#it flash it with your trucks program before you get it. It costs a few hundred extra to have this done, but you can't be blamed for a bad ECM (or program).
it was mentioned here: http://rawze.com/forums/showthread.php?t...7#pid40577

also you should run the truck with that factory program for 10 minutes at bare minimum,.. but perhaps longer if you need to ensure your problem got solved ... before putting any custom program in it.

[Gump12b]

Updates: All connections look good, all inline fuses look good, tight connections on every fuse. Bus fuses are making good contact. I was able to get the truck to run for a little yesterday, and when it shut off I did the bulb test on the 4 pin connector. It did perfectly fine.

I am led to believe that Rawze is correct and the ecm is bad. I’m thinking it’s just like Brocks ecm in that video where the 4 pin connector is soldered to the board. What baffles me is that it passes the tap test and I verified it again yesterday that no amount of tapping causes the issue. I don’t want to take the ecm apart and I haven’t turned my old one in for a core. I went through the local dealer to get this replacement ecm since I get a discount there and they were much cheaper than straight from Cummins. One thing I will say about this dealer is they always have the lowest prices on Cummins parts and have for years been much cheaper than Cummins, they have a truck go 10mins down the road everyday and pick up their parts right from Cummins. I’ve got a feeling I’m going to have to eat this ecm cost and buy another, I wish I had seen your thread Rawze before I got into this ecm. I could kick myself in the butt for not letting them program it, then again they may not have had an issue with it and I’d be in the same boat.

Has anyone else had an ecm lose connection like this and it still passes the tap test?

[Gump12b]

Called dealership I bought the ecm from, of course they want the truck before they can verify the ecm is bad. Same thing at Cummins but I talked the service manager into letting me bring them the ecm and put it on their bench cal and see if they have the same issue as me with it losing power, they also want the original one to try it out. They claim they want to make sure they can get the right parameters off for a new ecm if they confirm that’s the issue.

Main worry is with truck being demandated will they see the different tune? I have not personally tuned one I’ve only had unilevers do the programming. Should I be worried about the seeing the tube or should I consider taking my truck to them?

[Unilevers]

just flash it stock, its easy to do

[Gump12b]

New developments! I will post a video (as soon as I figure out how) of what I’ve gotten the ecm to do after the engine is warm. Yesterday was mid 90s here in Va and now that I think about it the days that this thing wouldn’t start at all or would only for a few mins it was very hot like upper 90s.

After doing as uni suggested and flashing it back stock I decided to see if I could get it to remain in the “lost connection” state before taking for Cummins to hook it up their harness. I had to take it loose anyways so I decided to tap it against the engine after I ensured it shut off because it got hot.

It would cut out for a second after I tapped it (kinda hard) against the side of the engine, sometimes it would come back on, sometimes it stay off, and it would go on/off/on/off, or it would take me unplugging and replugging the 4 pin connector.

I decided to try my original ecm, it was not warm, and it took very little tapping force to make it cut out.

Just thought I would update, that’s all I’ve got for now, will know more tomorrow.

[Chamberpains]

Post your video to YouTube then post a link here is the easiest way.