Sorry, Jeff... there's nothing more I can tell you. Here is the P0601 diagnostic procedure taken directly from Page 38 of the Drive book:
1) NOTE: This DTC indicates an internal PCM problem. If there are no possible causes remaining, view repair*.
Replace and program the Powertrain Control Module in
accordance with the Service Information.
* This is my asterisk, the bold type was theirs. The last thing stated in any of our diagnostic procedures when
the last thing has already been suggested (in this case nothing because no external
tests are needed or possible), it directs us to "view repair".
I'd like to render an opinion, but electronic text is forever these days and that's what lawyers get paid for. Let's just say that I strongly believe you have gotten bad controllers and leave it at that. I'll be glad to opt out of your question if you think a second opinion would help. I'm not upset with you, Jeff. I know you're in a difficult position and it looks like we've come to a dead end at this point.
Let me know and I'll opt out to open your question to the JA community.