2012 Mack MP8 won’t turn off when key is turned

Hey y’all I’ve been fighting this problem for the last week. truck is a 2012 Mack cxu613 with the Eaton fuller autoshift 10speed. i can drive for about 8-10 miles before the trans flashes and locks me in whatever gear I was in until I can stop and then it locks into 2nd. If I put it neutral it will hold for a min then all the trans functionality disappears and all lights on the control panel go away. I try to shut the key off but the engine stays running and the dash cluster and heater fans remain running radio and cb go off. I have To pull the pre ems fuse or relay to get it to shut down and that relay is pretty warm to the touch if I leave the relay out for ten min or so everything operates as it should. If I plug the relay back in immediately it powers everything the ignition lug powers ie dash cluster, heater fans etc. I have pulled just about every connector, the fuse panel and traced all the wires in and under the truck looking for a short but there is nothing.

 

I was thinking vecu honestly.

 

So when it faulted I had my diag software hooked up and it threw a code for the vecu power supply relay low voltage or shorted.
Anyone know where the vecu relay is?

 

So update. Talked with eaton today and the harness and tcm tested good as they walked me through it.
Once the truck faults the tcm does not get power and all power is being shorted somewhere and sent to the vecu or ignition power lug even with key off. I am starting to believe it’s a shorted relay or stuck relay that resets after ten min until the next fault just a matter of finding out where the short to power is and what is causing it.

 

Ok I think I got it. The auto resetting circuit breaker for the trans was popping and losing power to the trans which in turn the truck lost communication with the trans and it couldn’t start a power down sequence in the ecm causing the dash and engine to stay on. I replaced the circuit breakers and all is normal at the moment.