Ford F-150 2015–2019 — technical service bulletin
Bulletin TSB19-2121 · NHTSA communication 10160863 · issued May 15, 2019
Technical service bulletin
communication type
Engine and Engine Cooling
component
2015–2019
model years
5
vehicle entries
Official summary
Some 2015-2019 F-150 vehicles equipped with a 3.3L, 3.5L Duratec, 3.5L EcoBoost and 5.0L engine and equipped with a block heater built on or before 1-Jan-2019 may exhibit a lack of heat concern from the heating ventilation and air conditioning (HVAC) system when operating the vehicle consistently in temperatures that are below -20à  â  C (4à  â  F). This condition may be due to deposits from the engine coolant becoming trapped in the heater core. To correct the condition, flush the cooling system and replace the heater core. Follow the Service Procedure steps to correct the 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.