The engine warning light came on in my ELgrande . as far as I can tell everything is ok , but it tells me there is an electrical problem . So I have bought a fault finder that you plug in to isolate the fault . Never used one before have you ?
I have a Scangauge which can be fixed in the car to give various readings speed, rpm, water temp and many more but it can also be used as a fault finder and also to clear any faults that do pop up. The Focus threw a fault (engine management light came on) I plugged the Scangauge in, identified the code and fault, cleared it and it hasn't made a return. It happened after Jackie stalled the car, a rare event but we reckon the stall caused the car to see a fault.
They've probably improved them since I bought mine 12 years ago. I had an intermittent fault on my Ford and it kept going into limp home mode.when I plugged it in it kept telling me there was no fault then eventually it came up with a code that no one could find out what it was . I managed to find out what the problem was, It was a sticking heater plug relay.
Apparently it went into limp home mode because the emissions might have been raised slightly and putting me into a different road tax band and not because it was dangerous for the engine.