Mercedes-Benz bulletin LI82.85-P-068986
What it saysComplaint <p> After a software update, the MBUX multimedia system (A26/17) may incorrectly display the fault code B19C804 "Software tampering has been detected. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Dec 6, 2024, received Dec 11, 2024, about the electrical system. It names 34 model years (2016–2025). 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 communicationComplaint <p> After a software update, the MBUX multimedia system (A26/17) may incorrectly display the fault code B19C804 "Software tampering has been detected. There is an internal fault". </p> <p> </p> <p> Note: If there are no relevant customer complaints, then the DTC can be ignored as it does not directly affect functionality. If there is a customer complaint in addition to the above DTC, further diagnostic measures must be performed. </p> Cause The current software release of the MBUX multimedia system (A26/17) Remedy <p>Update the A26/17 to newest available software release.</p><p> </p><p>Note: Do not replace any parts.</p>
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI82.85-P-068986 | Service bulletin | Dec 6, 2024 | 11011767 | not found |
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 34 model years this bulletin names have filed 1,514 complaints with NHTSA since 2015. 324 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.
On the 2020 Mercedes-Benz GLE-Class, the 13 owners who gave an odometer reading for Electrical System reported it at a median of 6,615 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
During regular use my 2023, Mercedes Cla 250, had a fault in the instrument display in which the display shut off completely. Only the media display remained on, however the media display is completely useless in this scenario, only the instrument display can show the speed in which the vehicle is traveling and the Rpm range in which the…
2023 Mercedes-Benz CLA-Class · Electrical System · filed with NHTSA Oct 3, 2025 · ODI 11691317
this car really has a lot of issues and honestly if I didn’t know what to do last night and didn’t know about cars, it could have seriously cost me my life but luckily I was able to move out the way of a truck that was coming fast behind me while I was at a traffic light and when the light turned green the car would not start back up…
2022 Mercedes-Benz GLB-Class · Electrical System · filed with NHTSA Aug 10, 2024 · ODI 11607732
As I approached a red light and removed my foot from the gas pedal to brake, my dashboard displayed several alarming messages: “Active Brake Assist Functions Limited See Owner's Manual,” “Active Blind Spot Assist Inoperative,” “To Deselect P or N Depress Brake and Start Engine,” and “Traction Control Inoperative See Owner's Manual.”…
2022 Mercedes-Benz GLS-Class · Electrical System · filed with NHTSA Jun 4, 2024 · ODI 11592527
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 group175 other manufacturer communications filed against these Mercedes-Benz models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI47.70-P-079912 | Service bulletin | Sep 29, 2026 | Complaint Vehicle will not start after DC charging Warning in the instrument cluster related to High‑voltage on board electrical system The… |
| LI46.00-P-081006 | Service bulletin | Sep 29, 2026 | Complaint The vehicle pulls to the left or right. Cause In vehicles with Car Package Release "CPR" 2.1.0 or prior, the calibration value for… |
| LI54.71-P-080956 | Service bulletin | Sep 25, 2026 | Complaint 174 with MB. OS 2.1.1 ‑ Driver Assistance System Limited in Instrument Cluster and Does Not Self‑Extinguish. When vehicle is shut… |
| LI54.30-P-080963 | Service bulletin | Sep 17, 2026 | Complaint Issue after OTA Update IC Odometer Reading blank("_ _ _ _") IC Maintanence data unavailable Cause OTA Update E61.0 Remedy In the I… |
| LI82.60-P-080383 | Service bulletin | Sep 15, 2026 | Complaint Radio station cover art does not refresh when switching stations. The UI continues to show the old station’s artwork instead of up… |
| NCU - 2026090001 | Service campaign | Sep 11, 2026 | Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the control unit software for… |
| LI54.71-P-079104 | Service bulletin | Sep 11, 2026 | Complaint Traffic sign symbol for "Traffic Sign Assist" is blinking in instrument cluster without obvious cause usually with one of the foll… |
| ANN - MY27 XENTRY Comm. | Other | Sep 11, 2026 | A solution for the XENTRY and MY27 167 communication issue is now available through addon 26.6.1.33608. If after ensuring you've installed l… |

Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Mercedes-Benz, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mercedes-Benz LI82.85-P-068986 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 LI82.85-P-068986 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 Mercedes-Benz warranty extension on file lists the ones Mercedes-Benz has filed.
Which vehicles does LI82.85-P-068986 cover?
The manufacturer filed it against 34 model years: 2022 Mercedes-Benz A-Class, 2021 Mercedes-Benz A-Class, 2020 Mercedes-Benz A-Class, 2019 Mercedes-Benz A-Class, 2024 Mercedes-Benz CLA-Class, 2023 Mercedes-Benz CLA-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.