Hyundai Sonata Hybrid 2020–2023 — technical service bulletin
Bulletin 23-HC-002H · NHTSA communication 10241883 · issued Aug 25, 2023
Technical service bulletin
communication type
Power Train
component
2020–2023
model years
4
vehicle entries
Official summary
This bulletin provides information related to the Engine Control Module (ECM) software update and coolant replacement for 2020-2023MY Sonata Hybrid (DN8 HEV) vehicles to improve the coolant filling mode by discharging air bubbles.
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.