Kenworth T680 2016 MX-13 CAN communication issues

Yes, it feels like something is becoming too hot or like that….
Key cycle not always bring it back.
Batteries tested, all great, cables cleaned
Relays all new now, that what I thought was the problem. But not Mecanic did some wires under hood, but still nothing. Can’t work because of that. Also I forgot, it’s automatic and transmission shift lite “service” flashing. But when it resets by itself no lights at all for a short period of time

 

Im sorry I have given you the silver bullets that I can think of. Without seeing fault printouts from all modules I am truly only pointing at common failures. Engine printouts from Davie and trans printouts from Service ranger may offer some insight and a direction for me if you have them to share?

 

Unfortunately don’t have it now. Will drop the truck to dealer I’ve bought it from for diagnostic. But looks like they don’t know what is this. Because it already was there 3 days, they said they’ve fixed it, but still the same.
Only done 1200 mi after purchase, truck has 277 k miles.
Also discussing a trade in options, but they only have Volvo with d13 and international with Cummins. Both more miles than my truck…

 

Request the printouts and post them up here. Neither of your trade options sound like good ones.

You need to find a good electrical shop that can duplicate and trace the issue.

What are conditions when it occurs? Random, raining/wet out, Hot, cold, bumps? The solution to your headaches will be in the details you provide to the service location.

 

First it was like that: could start with no problems, truck running 3-5 min than stalls, and key cycle helped. Than it became more often and it happened right on the road, but again fixed by itself. Finally it started to show warning lights and truck won’t start at all. One more thing I forgot to tell: pulling out big relay under hood (main relay) helps to reset it for a little bit.
Also we had a rain recently which made it worse, or it’s just set of circumstances…

 

You are likely losing power or ground to the engine ECM to allow it to stall. Green wires or bad connections somewhere. A shakedown of the powers and grounds to the ECM is where I would start.

Sure would be nice if it would just break completely so the shop can find it?

Hope you get it handled.

 

That’s what self diagnostic actually showed me today: code 36, which means power to ECM. I believe you right, but this is my first truck. I’m good in regular car fixing but never worked on trucks yet.
And yes, permanent failure would be easier, and I was “happy” when it didn’t start at all. I was hoping that’s it, they will find it now. Because there is nothing worse than phantom failure ‍

 

UPDATE
Today I decided to check everything out again by myself. Took a flashlight and inspected all the connections under hood and under truck. Checked everything I could reach. All looks good. So I started the truck. First 3-4 min nothing was wrong. Then I noticed that DEF gauge came to 0, and red light flashing, but no warning lights on a dash. In couple minutes CEL came on, and after stop/start key cycle dash showed: stop engine immediately! You gonna be kidding me?!?!? Really? REALLY????
But now it doesn’t shut off by itself and no transmission malfunction light…. Omg, what a crap those modern cars and trucks…

 

Another update:
Codes picture. I was told that this is another issue not related with previous one. And def level sensor needs to be replaced.

 

Yup, I agree.