Cadillac XT4 2019–2021 — technical service bulletin
Bulletin 21NA090 · NHTSA communication 10199264 · issued May 10, 2021
Technical service bulletin
communication type
Power Train
component
2019–2021
model years
3
vehicle entries
Official summary
This service bulletin provides a repair procedure to correct a customer concern of Whistle or Hoot/Woot Noise Heard from Under Vehicle in Cold Ambient Temperatures.
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.