Hyundai Sonata 2024–2026 — warranty extension
Bulletin 7/13/2026 TSB · NHTSA communication 11035140 · issued Jul 13, 2026
Warranty extension
communication type
Electrical System
component
2024–2026
model years
3
vehicle entries
Official summary
Certain Sonata (DN8) vehicles may exhibit intermittent battery discharge condition due to the air conditioning controller not fully powering down after the vehicle is turned off and parked. This bulletin provides the procedure to update the ATCU (Air Temperature Control Unit) software; the revised logic improves controller shutdown to prevent battery drain and corrects a condition where the HVAC control display may appear blank when climate remote start is activated via Bluelink.
Vehicles covered
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.