The Integrated Thermal Management System (ITMS) failed/ malfunctioned. Available for inspection. My car completely lost power on the interstate and it was 70 mph speed limit, I had a semi behind me. Iâm taking to the dealer when Iâm off in 3 to 4 weeks. Problem has been reported by other owners, as well as Hyundai Sonata N-Lines. Also video evidence. Not been inspected yet, but thatâs the problem. No warning lights. Could see the temp gauge moving up when I accelerated. Problem happened when it was cold outside, popped the hood and engine wasnât overheated at all, ITMS failed.