Hyundai Elantra GT 2018–2019 — technical service bulletin
Bulletin Campaign T3T Dea · NHTSA communication 10169378 · issued Nov 15, 2019
Technical service bulletin
communication type
Engine and Engine Cooling
component
2018–2019
model years
2
vehicle entries
Official summary
Hyundai has launched a Service Campaign to update the ECM (Engine Control Module) software for DTC P0128: Coolant Thermostat (Coolant Temp below Thermostat Regulating Temperature) logic improvement.
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.