I have tried unplugging EVERYTHING at once. Boxes, SWM power.
Call Directv support; they have extended hours for support. My guess is that the code is something they have in place to help them. That particular code is not yet published, where shared publicly that is.
If you want to do some up front troubleshooting, have you tried the coax diagnostics? On front panel of the 24 series boxes, you can press and hold right arrow and then briefly press guide and release both buttons and a diagnostics will pop-up. You can get results for the SWiM paths and connected DECA devices.
Not sure if this procedure has been posted in this forum but there are extensive details on this thread in another forum: DBSTalk.Com