Honda bulletin A21100B
What it saysServiceNews Article - There are several possible causes for the SRS DTC U3000-49 (Internal Failure of the SRS Unit) to be stored. NHTSA’s full summary ↓
Honda filed this with NHTSA as a service bulletin dated Jan 29, 2022, received Oct 28, 2021, about the air bags — 3 documents under this number. It names 21 model years (2020–2021). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
Get the next Honda bulletin for your model by email Weekly, only when something new is filed. Nothing else; one-click unsubscribe.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationServiceNews 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 situations, the SRS Unit should be last on the list of components to replace. Here is a quick tip for troubleshooting a faulty seat weight sensor.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| A21100B | Service bulletin | Jan 29, 2022 | 10206988 | PDF, 50 KB |
| A21100B | Service bulletin | Jan 4, 2022 | 10206395 | PDF, 50 KB |
| A21100B | Service bulletin | Oct 22, 2021 | 10202598 | PDF, 36 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
Find the srs malfunction warning lamp/light for the 2021 Accord →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
Email me new Honda bulletins for one of these models
A weekly email, sent only in a week when Honda files something new with NHTSA for the model you pick — service bulletins, campaigns, warranty extensions, over-the-air notices, every model year. Nothing else is sent; one-click unsubscribe in every message. Separate from recall alerts.
What owners reported
Source: NHTSA complaint databaseOwners of the 21 model years this bulletin names have filed 4,367 complaints with NHTSA since 2015. 122 of them name Air Bags, Seats — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
I received a 2021 Insight Seat Weight Sensor Safety Recall in September 2025 saying that recall replacement parts were now available at Honda Dealers. Ever since I received this notice, none of the Atlanta area Honda dealers are able to remedy the defect in my vehicle due to lack of parts, contrary to the notice saying parts are available
2021 Honda Insight · Seats · filed with NHTSA Dec 26, 2025 · ODI 11707122
The contact owns a 2021 Honda Civic Hatchback. The contact received notification of NHTSA Campaign Number: 24V064000 (Air Bags); however, the part to do the recall repair was not yet available. Several local dealers were contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair.
2021 Honda Civic · Air Bags · filed with NHTSA Aug 12, 2025 · ODI 11680183
The contact owns a 2021 Honda HR-V. The contact received notification of NHTSA Campaign Number: 24V064000 (AIR BAGS); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue.
2021 Honda HR-V · Air Bags · filed with NHTSA Nov 13, 2024 · ODI 11624997
In depth: 2020 Honda CR-V airbag problems →
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the air bags
Source: same model, same component group2 other manufacturer communications filed against these Honda models under the same component group (air bags), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| ATI&09192023901 | Service bulletin | Sep 19, 2023 | Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2023 HR-Vs & CR-Vs with a customer complaint of the SRS light… |
| ATI&09052023901 | Service bulletin | Sep 5, 2023 | Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2023 HR-Vs & CR-Vs with a customer complaint of the SRS light… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Honda, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Honda A21100B a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the A21100B repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every Honda warranty extension on file lists the ones Honda has filed.
Which vehicles does A21100B cover?
The manufacturer filed it against 21 model years: 2021 Honda Accord, 2020 Honda Accord, 2021 Honda CR-V, 2020 Honda CR-V, 2021 Honda Civic, 2020 Honda Civic and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.