Hyundai Sonata 2011–2014 — technical service bulletin
Bulletin 5NP-D4B5F-04 · NHTSA communication 10110929 · issued Mar 14, 2017
Technical service bulletin
communication type
Equipment
component
2011–2014
model years
4
vehicle entries
Official summary
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.
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.