Upon acceleration the following lights illuminate once the engine reaches 3000-4000 RPM:

Engine Lights

A message; "Engine Fault" appears on the dash screen. Once this happens, the engine will no longer rev beyond the 3000-4000 RPM range.

On a few occasions this has also resulted in a steering assist fault, where the power steering cuts out, and usually this also causes the engine to idle, and will not rev at all.

I have the following Ford Fiesta Model

Ford Fiesta Mk6 Diesel

Various mechanics have looked into this issue and all come up with different theories on what might be causing the problem:

  • Faulty mass airflow sensor (this was replaced - no solution to faults)
  • Faulty alternator
  • Faulty ECU
  • Faulty fuel pump

Does anyone have any experience of this issue, and what might be causing it?

  • 1
    In this case only a diagnostic interface can tell what's wrong (the car of course won't display the error code on the dashboard itself - that would be too easy), so go to the dealership or buy a good counterfeit of the diag interface (as the official one isn't for sale obviously).
    – user5106
    Mar 31 '15 at 16:31
  • I agree with the comment to get the codes read. With the codes it's going to be far easier to help you with your issue. Jul 31 '15 at 12:38
  • Agreed. You can get a reader for about $15 on Amazon. Some repair shops do diagnostics for free. So does AutoZone.
    – Keith
    Oct 26 '15 at 1:34
  • Did you get this resolved? Can you give us an update?
    – dlu
    Oct 30 '16 at 21:36
  • Flagging as too broad since OP isn't responding to comments.
    – dlu
    Nov 20 '16 at 22:50