I've seen similar 3 times over the years.
All turned out to be location based.
In these cases it was location based RF signals.
2 turned out to be phone towers and the other 1 was close proximity to a nuclear power station.
If I remember there was a post on here many years ago with a ford cosworth which kept dying near heathrow airport due to radar interferance.
Don't know if there is any connection with your fault.