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Service bulletins for the 2026 Hyundai Sonata

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

20 on file from NHTSA, as of 2026-10-19.

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Only bulletins with component: Electrical system are shown. Show all

Bulletins, newest first
LA29-LA30 DCS2026-07-21. Warranty extension. ELECTRICAL SYSTEM. Certain 2024-2026MY Sonata (DN8) and 2024-2026MY Sonata Hybrid (DN8 HEV) 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. Technical Service Bulletins (TSB) 26-01-051H & 26-01-052H provide 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. Over-the-Air (OTA): This update can also be conducted via OTA. Customers can complete on their own if they have an active subscription to Hyundai Bluelink. A visit to the dealership is not required. Deployment of the OTA to Bluelink customers is planned to start the week of 07/13/26.
26-01-052H TSB2026-07-21. Warranty extension. ELECTRICAL SYSTEM. Certain Sonata Hybrid (DN8 HEV) vehicles may exhibit intermittent battery discharge conditions 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 Air Temperature Control Unit (ATCU) 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.
7/13/2026 TSB2026-07-21. Warranty extension. ELECTRICAL SYSTEM. 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.
26-01-035H TSB2026-04-15. Service campaign. ELECTRICAL SYSTEM. Some vehicles may exhibit a loss of connectivity or interruptions in the middle of using Bluelink functions. This may be due to an occasional disconnection on Verizon’s communication network. Follow the procedures in this bulletin to verify Bluelink Data Communication Unit (DCU) network connection and if needed, reset the DCU in Dealer Mode to resolve the connection.
TEB/TEBA DCS2025-12-16. Service campaign. ELECTRICAL SYSTEM. Hyundai Motor America is currently investigating an ongoing issue with software GDS event #1302. The matter is being investigated. We will provide an update once the issue is resolved and the suspension is lifted.
25-01-075H/076H DCS2025-10-29. Service campaign. ELECTRICAL SYSTEM. Certain Sonata (DN8) and Sonata Hybrid (DN8 HEV) vehicles may experience battery drain due to the air conditioning controller not shutting down completely while the vehicle is parked and turned off. TSBs 25-01-075H (for Sonata vehicles) & 25-01-076H (Sonata Hybrid vehicles) provides instructions to perform a software update for the ATCU (Air Temperature Control Unit).
25-01-076H TSB2025-10-29. Service campaign. ELECTRICAL SYSTEM. Certain Sonata Hybrid (DN8 HEV) vehicles may experience battery drain due to the air conditioning controller not shutting down completely while the vehicle is parked and turned off. This bulletin provides instructions to perform a software update for the ATCU (Air Temperature Control Unit).
25-01-075H TSB2025-10-28. Service campaign. ELECTRICAL SYSTEM. Certain Sonata (DN8) vehicles may experience battery drain due to the air conditioning controller not shutting down completely while the vehicle is parked and turned off. This bulletin provides instructions to perform a software update for the ATCU (Air Temperature Control Unit).

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.