I wouldn't be surprised if the fix is literally a zip tie.

There's a thing called HALT/HASS. HALT stands for highly accelerated life testing. Basically you put a product under extreme stress and try to find the failure points and mitigate them. Temperature, vibration (simulated or track), humidty, power cycles, ... That said I've never seen one find everything. You can also do FMEAs, which again never find everything. In short this stuff is hard even for companies that presumably have lots of experience to draw on. Don't know if Ford did something dumb to miss this or it was just one of those, "oops we missed it" that happens.

I would think that any loose wiring harness, especially somewhere it could touch another part, would be reflexively corrected by the designer. But I don't know what the part and its surroundings actually look like.

I dunno, I think my angle of attack might be to not make the parking brake, which is also meant to be usable as an emergency brake in the case of hydraulic failure, fucking electronic.

Cable actuated parking brakes have served mankind perfectly well for over 100 years. I get that innovation needs to happen over time, but the whole electronic parking brake phenomenon I think is really a case of pushing in the wrong direction. It's needless complexity for the sake of needless complexity.

When competence is in play, a wire harness chafe issue is something that should be fairly readily accounted for in the design phase, I think. I'm not entirely sure an entire-truck-vibrator to snout out harness chafes is really necessary, but it's probably something that a company as large as Ford could build if they really felt like it. It could have been any wire in any harness, potentially, causing no end of superficially mysterious issues.

It's the best selling vehicle in the US, so yeah, the recall will be huge.

That's ~~2550~~ 255 vehicles for the lazy.

Edit:

I suck at math, but according to the upvotes so does everyone else