This from another forum might help ,
New Fiesta 'EAC FAIL' - Pete F
There were problems like this on early build Fiesta 1.4 and the only person who can fix it is your dealer I'm afraid. They'll probably have to reflash the latest software again.
It is possible, although unlikely, that there is a fault with one of the components but this should show up on a diagnostic check. Let us know if you're 3rd time lucky!
Posted on Wednesday 30th of December 2009Don't understand this? Ask a question