Ford bulletin SSM 54420
What it saysSome 2023-2026 F-Super Duty vehicles built on or before 01-Oct-2025 may exhibit a "Hill Start Assist Unavailable" and/or "Parking Brake Limited Function" message at vehicle start-up with diagnostic trouble codes (DTCs)… NHTSA’s full summary ↓
Ford filed this with NHTSA as a service bulletin dated Dec 3, 2025, received Dec 10, 2025, about the service brakes. It names 16 model years (2023–2026). 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 communicationWhat it applies to, as the document itself states it — the build window in the manufacturer’s own words, read by machine from the PDF NHTSA serves. The build date is on the certification label in the driver’s door jamb; the dealer settles a borderline vehicle by its VIN.
Some 2023-2026 F-Super Duty vehicles built on or before 01-Oct-2025 may exhibit a "Hill Start Assist Unavailable" and/or "Parking Brake Limited Function" message at vehicle start-up with diagnostic trouble codes (DTCs) U0151, U023A, U0159 and/or U0146 stored in the anti-lock brake system (ABS) module. These DTCs and/or U0415 may also be present in various other modules related to "invalid data received from the ABS control module". This may be due to the software in the ABS module. To correct the condition, reprogram the ABS module using the latest software level of the Ford Diagnosis and Repair System (FDRS) scan tool. For claiming, use causal part 2C219 and labor operations 2219D and 2219D44.
Trouble codes it names: U0146 U0151 U0159 U023A U0415
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| SSM 54420 | Service bulletin | Dec 3, 2025 | 11026508 | PDF, 69 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.
Model years it names
Source: as the manufacturer filed themAlso filed against model years this site has no page for: 2023 Ford F-550 SD; 2024 Ford F-550 SD; 2025 Ford F-550 SD; 2026 Ford F-550 SD.
A 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 12 model years this bulletin names have filed 228 complaints with NHTSA since 2015. 28 of them name Service Brakes — 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.
After the vehicle was jumpstarted the vehicle failed to correctly enter gear- when shifting into reverse it instead rolled forward downhill. The following systems also displayed failure warnings: ABS Traction Control Parking Brake ( Parking brake also showed as activated when it was not active- it would audibly disengage but the parking…
2026 Ford F-250 Super Duty · Service Brakes · filed with NHTSA Jun 8, 2026
there hasn't been an incident per say and these might not be a safety concern. however i would like to list my grievances here just so there's documentation. my radio has some type of glitch where the phone calls get static like its digital, also the mirrors don't fold in all the time when locked with the key fob, the brakes have…
2023 Ford F-250 Super Duty · Service Brakes · filed with NHTSA Mar 15, 2024
2k miles on a new 2026 ford transit. While in traffic there was sudden braking I had plenty of space in front of me (also reported by the driver in front of me) I was not able to stop in time which resulted in rear ending another driver. My abs acted extremely loose, as if I was on ice on a clear day 80 degrees.
2026 Ford F-250 Super Duty · Service Brakes · filed with NHTSA Jun 5, 2026
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 service brakes
Source: same model, same component group10 other manufacturer communications filed against these Ford models under the same component group (service brakes), newest first. The eight newest are listed; the rest are on the Ford list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| SSM 54448 | Service bulletin | Dec 16, 2025 | Some 2017-2026 F-Super Duty vehicles may exhibit a pull/drift condition during braking. This may be due to the brake pads needing to be brok… |
| SSM 54160 | Service bulletin | Aug 22, 2025 | Some 2023-2025 F-Super Duty vehicles may exhibit a "Hill Start Assist Unavailable" and/or "Parking Brake Limited Function" message at vehicl… |
| SSM 53892 | Service bulletin | Jun 11, 2025 | Some 2023-2025 F-Super Duty vehicles may exhibit a "Hill Start Assist Unavailable" and/or "Parking Brake Limited Function" message at vehicl… |
| SSM 53239 | Service bulletin | Dec 17, 2024 | Some 2023-2025 F-Super Duty vehicles may require a replacement of the anti-lock brake system (ABS) module (2C219) during normal workshop man… |
| SSM 52590 | Service bulletin | Jun 5, 2024 | Some 2023-2024 F-Super Duty vehicles may require a replacement of the anti-lock brake system (ABS) module for various reasons. Replacing the… |
| SSM 52308 | Service bulletin | Feb 29, 2024 | Some 2022 F-Super Duty vehicles equipped with a 12.3 inch center display screen and 2023-2024 F-Super Duty vehicles may exhibit DTCs B1D08:1… |
| 24G01 | Service bulletin | Feb 22, 2024 | Certain 2023-2024 Model Year F-250/350 Vehicles - Brake Vacuum Sensor Replacement |
| SSM 52015 | Service bulletin | Oct 24, 2023 | Some 2023 F-Super Duty vehicles equipped with vacuum assist brakes and built on or before 01-Aug-2023 may exhibit an illuminated brake warni… |
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 SSM 54420 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 SSM 54420 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 SSM 54420 cover?
The manufacturer filed it against 16 model years: 2026 Ford F-250 Super Duty, 2025 Ford F-250 Super Duty, 2024 Ford F-250 Super Duty, 2023 Ford F-250 Super Duty, 2026 Ford F-350 Super Duty, 2025 Ford F-350 Super Duty and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone. The document itself sets the build window: 2023-2026 F-Super Duty: built on or before 1 Oct 2025 — the build date is on the certification label in the driver’s door jamb.