TSB - COMBINATION TSB/SERVICE ACTION: ENGINE VIBRATION AT IDLE (SA312) - REVISED - This bulletin provides the procedure to replace the alternator pulley on some 2014-2016MY Forte (YD) vehicles with 1.8L and 2.0L Nu engines, produced from February 18, 2013 through July 18, 2016, which may experience an unusual engine vibration at idle that is sometimes more prevalent under certain electrical loads.