Hyundai Sonata 2024–2025 — technical service bulletin
Bulletin 26-EM-009H TSB · NHTSA communication 11030329 · issued Mar 24, 2026
Technical service bulletin
communication type
Electrical System
component
2024–2025
model years
4
vehicle entries
Official summary
Some Sonata (DN8) and Tucson (NX4/NX4A/NX4M) vehicles equipped with the 2.5L Theta III GDI engine may display a warning lamp and store Diagnostic Trouble Code (DTC) P2B59F0, which relates to the Integrated Thermal Management Module (ITM) circuit due to a logic error. This bulletin provides instructions to update the Engine Control Module (ECM) logic to correct this condition.
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.