Hyundai Sonata Hybrid 2020–2023 — technical service bulletin
Bulletin 23-01-093H · NHTSA communication 10249698 · issued Jan 10, 2024
Technical service bulletin
communication type
Engine and Engine Cooling
component
2020–2023
model years
4
vehicle entries
Official summary
This bulletin provides the procedure to update the Hybrid Control Unit (HCU) and Dual Automatic Temperature Control (DATC) software to help improve coolant flow to the Exhaust Heat Recovery System (EHRS).
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.