On September 11, 2014 the Office of Defects Investigation (ODI) opened a Preliminary Evaluation (PE14-028) to investigate claims of doors failing to latch and/or inadvertently opening on model year (MY) 2011-2013 Ford Fiesta vehicles. ODI has received 207 unique reports related to the alleged problem, with sixty-five claiming that the door(s) opened inadvertently while the vehicle was in motion. Two injuries were reported, both caused by a rebounding door striking a consumer after they attempted to close it. In response to ODI's Information Request (IR), Ford Motor Company (Ford) responded with 451 unique reports related to the alleged defect.One claim involved an incident in which property damage incurred after a door opened while driving at low speed and struck another vehicle. Ford also submitted 1,079 warranty claims related to door latch failures. Additionally Ford informed ODI in its IR response that MY 2013 Ford Fusion and Lincoln MKZ vehicles utilize the same door latch as the MY 2011-13 Fiesta. In it's response, Ford stated that it does not believe that a latched door experiencing this condition will inadvertently unlatch and that there are many overt warning associated with a door that does not latch. ODI noted that the rate of occurrence for this failure is comparable to other door latch failure investigations and questions the effectiveness of warning signals given the number of complainants alleging that the door(s) opened while the vehicle was in motion. Therefore, ODI is upgrading this investigation to an Engineering Analysis (EA15-002) in order to further investigate the scope, frequency and consequence of this failure.ODI reports cited above can be reviewed at www-odi.nhtsa.gov/complaints under the identification (ODI) numbers listed in the attached document.