Fiesta power train issue?

Hi I have a 2009 ford fiesta on a 58 plate. The power train light has come on this evening. The first time it happened I didn't notice an issue, parked the car turned it off. When I came back and started it again the warning light had gone but I noticed when revving upto 3/4000 this causes the power train light to come on, once it's on if I go anywhere near 3000 revs the car cuts out immediately. Any idea on what the issue could be & aprox cost of repair?