Lincoln bulletin SSM 53993
What it saysSome 2025 Aviator/Navigator vehicles equipped with a 24 channel audio digital signal processing module (DSP) (minor feature code IDBBN) may exhibit a no audio/sound condition with no communication with the DSP. NHTSA’s full summary ↓
Lincoln filed this with NHTSA as a service bulletin dated Jun 27, 2025, received Jul 2, 2025, about the electrical system. It names 2 model years (2025). 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 communicationSome 2025 Aviator/Navigator vehicles equipped with a 24 channel audio digital signal processing module (DSP) (minor feature code IDBBN) may exhibit a no audio/sound condition with no communication with the DSP. To confirm a vehicle is built with a certain minor feature code, review the build information by double-clicking the vehicle identification number (VIN) in the upper left corner in the Professional Technician System (PTS). This concern may be due to the software in the DSP. To determine if it is a software concern, remove the DSP fuse, F40 for Aviator or F5 for Navigator, and inspect the fuse for an open and make sure the fuse has proper blade contact. After one minute, reinstall the good fuse. If the concern is still present or a fuse concern is found, continue with normal Workshop Manual diagnostics, Section 415-00 Information and Entertainment System > General Information > Diagnosis and Testing. If communication has been re-established with the DSP, reprogram the DSP using the latest software level of the Ford Diagnosis and Repair System (FDRS) scan tool. For claiming, use causal part 18B849
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| SSM 53993 | Service bulletin | Jun 27, 2025 | 11020060 | PDF, 71 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 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 2 model years this bulletin names have filed 31 complaints with NHTSA since 2015. 8 of them name Electrical System — 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.
This vehicle has been returned to service 5 times. It is currently in service for the same 4 issues that it was taken to service for the very first time on 12/10/2025. This includes inappropriate braking on the interstate, driver window malfunction, the key intermittently stops working, and the connectivity does not regularly work.
2025 Lincoln Navigator · Electrical System · filed with NHTSA Feb 2, 2026 · ODI 11715174
Multiple loss of power, misfires, rough running and abnormal shifting. These events have put my family and I at risk as well as posing a significant risk to other drivers sharing the road due to the sudden loss of power while on the highway. Lincoln is dismissive and not taking this seriously.
2025 Lincoln Aviator · Electrical System · filed with NHTSA Sep 15, 2026 · ODI 11764477
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 electrical system
Source: same model, same component group164 other manufacturer communications filed against these Lincoln models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Lincoln list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| SSM 55262 | Service bulletin | Oct 22, 2026 | Some 2027 Expedition/Navigator vehicles equipped with power running boards built on or before 13-Sep-2026 may exhibit an intermittent condit… |
| 26-2431 v2 | Service bulletin | Oct 22, 2026 | This bulletin supersedes 26-2226. Reason for update: update the Service procedure for 2021-2022 F-150 3.5L EcoBoost vehicles with new Ford D… |
| SSM 55258 | Service bulletin | Oct 19, 2026 | Some 2025-2027 Expedition/Navigator vehicles may exhibit an intermittent electronic static/buzzing/screeching/humming noise from the front a… |
| SSM 55256 | Service bulletin | Oct 16, 2026 | Some 2024-2026 Nautilus and 2025-2027 Explorer/Aviator vehicles equipped with power folding mirrors may exhibit concerns with the auto foldi… |
| TSB 26-2442 | Service bulletin | Oct 14, 2026 | This bulletin supersedes 26-2297. Reason for update: Add 2022-2025 Transit vehicles. Some of the vehicles listed in the model statement abov… |
| SSM 55241 | Service bulletin | Oct 12, 2026 | Some 2025-2027 Aviator vehicles may exhibit a "Door Fault Service Required", "Transmission Not In Park" and/or "Hill Start Assist Not Availa… |
| SSM 55220 | Service bulletin | Oct 6, 2026 | Some 2024-2026 Nautilus and 2025-2026 Explorer/Aviator/Expedition/Navigator vehicles may experience Android Auto connection or general Bluet… |
| SSM 55208 | Service bulletin | Sep 25, 2026 | Some 2024-2026 F-150, 2025 Explorer/Aviator, 2025-2026 Expedition/Navigator, or 2026 F-Super Duty vehicles may exhibit diagnostic trouble co… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Lincoln, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Lincoln SSM 53993 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 53993 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 53993 cover?
The manufacturer filed it against 2 model years: 2025 Lincoln Aviator, 2025 Lincoln Navigator. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.