Cadillac XT4 2019–2021 — technical service bulletin
Bulletin 21NA229 · NHTSA communication 10205561 · issued Nov 12, 2021
Technical service bulletin
communication type
Structure
component
2019–2021
model years
3
vehicle entries
Official summary
This service bulletin provides a procedure to install a winter grille cover to correct the customer concerns of Poor Engine Performance in Extremely Cold Weather Conditions, Charge Air Cooler Icing, Malfunction Indicator Lamp (MIL) Illuminated.
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.