MAKE:Hyundai MODEL:Sonata YEAR:2014 MILES:About 45000 ENGINE:2.4 DESCRIBE ISSUE.... Hi folks. Front defrost isn't working. Other modes work. Just wondering what's a reasonable time for a mechanic to fix this if TSB below is the problem. I don't have the full text, but guessing it's about replacing part 4 (97203-3S000 Separator) and/or 23 (97147-3S000 Door DEFROST) if not exactly TSB problem. Thank you. Manufacturer Communication Number: 5NP-D4B5F-04 NHTSA ID Number: 10110929 Some Sonata (YF) vehicles may develop a condition with the separator plate in the middle of the heater box (Heater & Evaporator Assembly) becoming warped and may cause interference against one or more of the internal flaps that control air flow to the vents. This condition may result in HVAC system exhibiting abnormal noise from the heater box, difficulty to control the vented temperature, blocked airflow due to improper mode control, and/or airflow stuck in defrost mode.