2009 GMC YUKON HYBRID Engine Problems

UPON BEING STOPPED AT A LIGHT AT A MAIN INTERSECTION AND THEN MAKING A LEFT HAND TURN, THE VEHICLE SHUT DOWN AND THE CHECK ENGINE LIGHT CAME ON THE PANEL. WE WERE ABLE TO COAST TO THE SIDE OF THE ROAD. AFTER A FEW MINUTES, THE VEHICLE STARTED UP FOR ABOUT 2MILES THEN SHUT OFF AGAIN. THE DEALER WAS NOT ABLE TO REPLICATE AND SAID NO ISSUES FOUND. THEY GAVE US THE VEHICLE BACK ONLY TO HAVE THE SAME ISSUE 5 DAYS LATER IN WHICH THE VEHICLE WAS TOWED BACK TO THE DEALER. DIAGNOSTICS THEN SHOWED A NEW BATTERY WAS NEEDED (?) AND A SEALANT RESEALED. WELL, A FEW DAYS LATER (LESS THAN A WEEK) IT HAPPENED AGAIN. THE DEALER HAS SINCE HAD THE VEHICLE, CLAIMING NOTHING IS WRONG AND HAS NOT BEEN ABLE TO REPLICATE. (ALL INSTANCES WERE DURING CONSTANT RAINFALL AND THE VEHICLE BEING DRIVEN AT LEAST 15-20MINUTES...