On November 24, 2015, Fiat Chrysler Automobiles, US LLC, (FCA), submitted a Defect Information Report (DIR) to NHTSA regarding a brake booster defect in approximately 105,458 model year (MY) 2013 through 2014Dodge Dart vehicles equipped with a 2.0L or 2.4L engine and produced between February 27, 2012 and January 23, 2014 (NHTSA Recall# 15V-800, FCA Recall# R63).According to FCA's DIR, the affected vehicles, may experience engine oil migration from the vacuum pump to the brake booster.Brake booster diaphragms exposed to oil may become damaged, resulting in a loss of brake power assist.FCA's recall will inspect the affected vehicles for the presence of engine oil in the brake booster.If no oil is found, the vacuum tube assembly will be replaced with a new design part.If oil is found, the vacuum pump, vacuum tube assembly, brake booster and master cylinder will be replaced.On June 18, 2015, the Office of Defects Investigations opened Preliminary Evaluation PE15-024 to investigate complaints alleging sudden increases in brake pedal effort with corresponding reductions in brake performance in MY 2013 Dodge Dart vehicles.The vehicle population and Failure Report figures in this resume are limited to the MY 2013 Dodge Dart vehicles that are the subject vehicles of PE15-024 all of which are included in the FCA recall.Some of the complaints reported hearing a popping noise during a brake application, which corresponded with sudden reaction force from the brake pedal, increased difficulty in applying the pedal and decreased brake effectiveness.FCA's analysis of field return booster assemblies indicated that some brake booster diaphragms exposed to the engine oil leak condition experienced sudden catastrophic ruptures, resulting in complete loss of booster function.This investigation is hereby closed based on the FCA recall.The VOQs associated with the closing of this investigation are: 10795258, 10795140, 10790670, 10790397, 10786152, 10786142, 10783492, 10783153, 10781418, 10779446, 10778244, 10776581, 10765244, 10765141, 10763566, 10763143, 10762254, 10761075, 10760965, 10759817, 10758707, 10758639, 10750235, 10748935, 10747634, 10745494, 10745395, 10745185, 10744577, 10744361, 10744052, 10736149, 10734443, 10734108, 10732067, 10726648, 10715993, 10713690, 10695212, 10668965, 10660526, 10659435, 10638228, 10620713, 10619184, 10610512, 10597398, 10583883, 10569142, 10565689, 10556239, and 10533008.