Well, that was uninformative. I don't remember what the code was, but it translated as "General electrical failure" which I'll take as a wiring fault. It is the APIM that's reporting it , so the problem is almost certainly between the APIM and the camera, which was what I already suspected.
Well, the next step will be to pull the APIM out and check the connectors on it.
I kind of wonder if the dealership tech did something when he replaced my TCM. If that's the case, then the dealership is not who I want to fix this, or who knows what I'll be chasing down next. (It COULD all be coincidence, of course, and I just got the car that had 5 different things about to fail within 6 weeks of each other.)
2012 Focus Titanium Hatchback
121,000 km, all stock
1990 Toyota Supra turbo
I think the cams are still stock...