I had a problem with my previous 2.0 TDCi S-max, when in France last year. One day, after driving it for several hours, it wouldn't start - turned over but didn't catch at all. After about 10 minutes it finally started. The next day it wouldn't start again - and no amount of trying worked. It got towed to the local (French) Ford dealer, where they eventually fixed it. Now, my French isn't great, but I think they said that they had no idea what was wrong with it, but when they reprogrammed the ECU it all magically started working again. Not what I wanted to hear before a 9 hour drive back to the UK, having to stop for fuel, lunch, etc on the way, but it did the trick, and didn't have the same problem again.