Hello I have a 2014 GMC Sierra 1500 and it has a list of codes pertaining to the loss of communication with the bus system, I found bulletin # PIT5457 and it sure seems to cover the same issue, but both locations are clean I have tried to follow the "circuit 5986" but can't seem to find a bad wire. Is there a diagram that would show as to where all this circuit runs? Has anyone seen any particular area of trouble I should be looking in? I also have three other codes that the bulletin don't cover and that is u0452-72, c0544-5a and u0151-00. all codes clear fine but return together and are intermediate and seem to come and go as it wants. I clear them it could be weeks or hours before they come back. Any help or ideas would be appreciated.
u0415, u0401, u0077, u0126 u0428, u0077, u0121, u0452-72, c0544-5a and u0151-00

If you can get to each end of a suspect circuit, you can test it with a volt meter.

Does the scan tool communicate with all the modules.

yes, I can talk to all modules, I have never been able to reproduce the issue when the scanner is hooked up that'* the hard part is it is very erratic I'm going to start pulling all modules tomorrow and checking for water intrusion and just keep following the bus wires the best I can. Testing the wires always passes if i could ketch it whiles it was acting up it would be a lot easier. I'm sure it'* something chaffed or a bad connection just where is the issue.

You'll not find it unless you load test the circuits..