Audi A4 2020–2021 — technical service bulletin
Bulletin TSB_2065234_2 · NHTSA communication 11023744 · issued Sep 10, 2025
Technical service bulletin
communication type
Electrical System
component
2020–2021
model years
6
vehicle entries
Official summary
This bulletin provides information when there is a tail light warning and variois DTCs are stored in the comfort module; B16D431, B16D631, B16D531, and/or B16D731.
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.