Yeah, I think I'll take your advice. I'll just keep running the car now that is good and working. And crossing my fingers. That it will work for a long while until I can retry maybe again in the spring or summer. It will just be a TCU change, nothing complicated. If it doesn't work, just change it back to the one that does work.

I think that it could be something rare that's going on with the car if it's not the TCU.

I'm not sure about the 0.27V either. I think I can retry the test later the other way you said. I want to get some smaller probe attachments. So I can stick it in there so it's not so hard just to hold it there. I'll see what readings I got on the digital meter on the battery in the morning.