Ford Mustang 2018–2021 — technical service bulletin
Bulletin TSB 21-2220 · NHTSA communication 10199522 · issued Jul 13, 2021
Technical service bulletin
communication type
Equipment
component
2018–2021
model years
4
vehicle entries
Official summary
Some 2018-2021 Mustang coupe vehicles may exhibit a sagging headliner or gap where the headliner meets the upper door weatherstrip. This may be due to an outward bent door frame moulding not allowing the weatherstrip to overlap the headliner properly. To correct this condition, follow the Service Procedure to replace the door frame moulding.
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.