Kenworth T680 CAN communication issues

I just bought a used 2016 Kenworth T680 May 7th 2019, and by June 6th 2019 I was in the shop for repairs. The issue is when am driving, the speedometer goes to 0mph and the engine fan turns on, after a few minutes, the ABS light comes on and DEF gauge goes to empty and flashes red, the transmission service lights on, the it won't shift out of the current gear.

Have been to a couple of Kenworth shops, first was in Grand Junction CO, they checked it out saying that it was the CAN and J1939 communication errors, that was being caused by a faulty alternator, and ground wires. Fixed it and paid $3500. Left Grand Junction on Wednesday 12th June.

On June 14th, just outside Kansas City, the same issue started, took it to another Kenworth shop in Olathe, this time round, it was VTG and NOX sensors, that were the issue, replaced them but the issue was still present, after an ECM swap with another truck, the issue was still present. They did a Pico scope and said that they had found the issue causing the CAN communication and resolved the issue on June 18th. Spent $9500

June 20th, the same truck issue started again in Arkansas, made it to a Kenworth shop in Memphis TN, this time they're saying it's the batteries that are low on voltage and need to be changed. Currently here. Update with new information as it comes.

Has anyone experienced this issue before, CAN communication between the engine and transmission, and how did they resolve it? Am feeling that the Kenworth guys are just guessing and when stumped they just clear he errors and send me on my way.

 

Thanks, anyway for tracking it down or it's a try and error kind of thing.

 

Truck update, just picked up the truck from the shop in Chicago. They changed the wiring harness and all looks good. The wiring harness was shorting and they couldn't pin point the issue so I decided to change it. Thanks for all the advice.