One problem related to speed sensor has been reported for the 2011 Ford Fiesta. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 Ford Fiesta based on all problems reported for the 2011 Fiesta.
Cruise control stopped working, keyless remote stopped working, odometer stopped working, tripometer stopped working. Took it to the factory and they said it was not covered, because it was 2 weeks out of 3 year bumper to bumper warranty. All of these are supposedly the result of a bad speed sensor between the axle and the transmission.