Ford bulletin 21N10 S1
What it saysCertain 2015 â 2021 Model Year Mustang Convertible Vehicles - Door Opens to Secondary Latch Position NHTSA’s full summary ↓
Ford filed this with NHTSA as a service bulletin dated Nov 15, 2023, received Dec 5, 2023, about the structure. It names 6 model years (2016–2021). 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.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationCertain 2015 â 2021 Model Year Mustang Convertible Vehicles - Door Opens to Secondary Latch Position
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 21N10 S1 | Service bulletin | Nov 15, 2023 | 10246072 | PDF, 1,349 KB |
What the document itself lists
The manufacturer titles it “Customer Satisfaction Program 21N10 - Supplement #1”.
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| BM5Z-5821813-A | Door Latch VIN Specific | — | eBay Motors → |
| GR3Z-5821812-B | Door Latch VIN Specific | — | eBay Motors → |
Read by machine from the document NHTSA serves (14 pages), read Sep 30, 2026. A part number is shown only where it matches Ford’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
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.
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 door for the 2021 Mustang →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.
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What owners reported
Source: NHTSA complaint databaseOwners of the 6 model years this bulletin names have filed 1,175 complaints with NHTSA since 2015. 123 of them name Structure, Latches/Locks/Linkages — 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.
On the 2017 Ford Mustang, the 21 owners who gave an odometer reading for Latches/Locks/Linkages reported it at a median of 60,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
Passenger side door will unlatch and open while driving, the digital alert will come on and say door ajar. Seems to do this when you're driving anywhere from 20 to 40 MPH. It has happened a total of 4 times in the last 2 weeks
2019 Ford Mustang · Structure · filed with NHTSA Nov 4, 2020 · ODI 11372983
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 structure
Source: same model, same component group3 other manufacturer communications filed against the Ford Mustang under the same component group (structure), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| SSM 54912 | Service bulletin | Jun 11, 2026 | Some 2025-2026 Mustang vehicles built on 01-Jun-2025 and through 25-Apr-2026 may exhibit a chirp and/or rattle noise from the left side of t… |
| TSB 23-2334 | Service bulletin | Oct 27, 2023 | This article supersedes TSB 21-2220 to update the model years affected and part list. Some 2018-2024 Mustang coupe vehicles may exhibit a sa… |
| SSM 51536 | Service bulletin | Apr 4, 2023 | For 2000-2024 Ford and Lincoln vehicles, swapping a module from a vehicle for diagnosis purposes is likely to cause errors and is not recomm… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Ford, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Ford 21N10 S1 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 21N10 S1 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.
Which vehicles does 21N10 S1 cover?
The manufacturer filed it against 6 model years: 2021 Ford Mustang, 2020 Ford Mustang, 2019 Ford Mustang, 2018 Ford Mustang, 2017 Ford Mustang, 2016 Ford Mustang. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.