TSB A21100B — Honda Service bulletin

A21100B is a service bulletin on file with NHTSA for the Honda Fit, 2020 model years, filed and re-filed as 3 documents. A TSB is factory repair guidance, not a recall — the repair is not automatically free.

What the bulletin says. ServiceNews Article - There are several possible causes for the SRS DTC U3000-49 (Internal Failure of the SRS Unit) to be stored. If you can duplicate the DTC, the troubleshooting will take you through the step-by-step process in isolating the faulty component. In most…

NHTSA's own summary of the document, quoted from the public manufacturer-communications file.

3Documents filed
1Vehicle named
1Model year

Vehicles and model years A21100B names

VehicleModel years
Honda Fit 2020

Every document filed under A21100B

Manufacturers re-issue a bulletin as the repair changes, and file separate copies for technicians and for owners. All of them carry the same number.

Document IDFiledType
A21100B January 29, 2022 Service bulletin
A21100B January 4, 2022 Service bulletin
A21100B October 22, 2021 Service bulletin

What A21100B covers

Airbags, Seats & interior — the component vocabulary NHTSA files this communication under.

← All Honda Fit TSB years TSB lookup by model

Questions buyers ask

What is TSB A21100B?

A21100B is a service bulletin filed with NHTSA by Honda, covering the Honda Fit across the 2020 model years. NHTSA's summary reads: ServiceNews Article - There are several possible causes for the SRS DTC U3000-49 (Internal Failure of the SRS Unit) to be stored. If you can duplicate the DTC, the troubleshooting will take you through the step-by-step process in isolating the faulty component. In most…

Which vehicles does A21100B cover?

NHTSA's file names Honda Fit (2020). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.

Is TSB A21100B a recall, and is the repair free?

No. A21100B is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.

How do I get the full text of A21100B?

Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under A21100B, its date, and NHTSA's own summary from the public file.

Data updated 2026-08-20 from NHTSA's public records

Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under A21100B. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.