Mazda MAZDA3 2019–2021 — technical service bulletin
Bulletin 09-026-21-3817 · NHTSA communication 10201773 · issued Sep 10, 2021
Technical service bulletin
communication type
Structure
component
2019–2021
model years
3
vehicle entries
Official summary
Some vehicles may experience white-streak stains appearing on the front door that look like they seeped out from under the outer mirror base. This is caused by water intruding from gaps of the outer mirror body and/or the hinge of the outer mirror, and corrosion occurring on the aluminum die-cast inner base in the outer mirror. Water, including white-salty corrosion, may drip out from gaps under the outer mirror base resulting in white stains on the front door.
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.