Past recalls and complaint experience indicate that the disintegration of vehicular components (not necessarily limited to fan blade assemblies) rotating at or near engine speeds can pose a hazard to individuals in proximity to the affected vehicle.This risk has frequently prompted responsive corrective field actions.This investigation (PE10-049) has not identified any (a) fatalities; (b) injuries; and/or (c) ?close-call incidents which, if reported, might provide an indication of the nature and severity of injuries which may occur if a fan blade installed in subject GMT vehicles were to fracture.Although ODI remains concerned about the potential for injury, ODI is closing this investigation because (1) the absence of an identified root cause or causal factors; and (2) the modest and declining level of complaint activity associated with fan blade breakage which indicates that the potential risk of injury is also small and diminishing.The closing of this investigation does not constitute a finding by NHTSA that no safety related defect exists.The agency reserves the right to take further action if warranted by circumstances.Further details are provided in the attached Executive Summary and ODI Technical Report Summary for PE10-049.