hi can anyone help my partner was driving our van 2 days ago she was going up hill she changed down a gear and the engine died and wont start now its the 2.0 jtd model we have had it pluged in to the computer but its saying theres nothing wrong even though the engine management light is still on.we have changed the diesel filter and this has made no difference, our mechanic is scratching his head and is at a bit of a loose end, any advice or suggestions would be greatly appreciated.