Mercedes-Benz bulletin LI54.10-P-079534
What it saysComplaint: Red 12 V battery warning message in IC DTC stored in EZS or currently: B161609 No DTC in DC/DC converter DC/DC converter is not providing any output voltage or output current Cause: Due to a reduction… NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Aug 8, 2025, received Aug 12, 2025, about the electrical system. It names 6 model years (2022–2025). 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: Red 12 V battery warning message in IC DTC stored in EZS or currently: B161609 No DTC in DC/DC converter DC/DC converter is not providing any output voltage or output current Cause: Due to a reduction in resistance at the HV voltage divider, the DC/DC converter measures an incorrect HV voltage. Regulation of the 12 V output voltage is therefore unstable or turns off. Remedy: Check of the DC/DC converter via XENTRY Diagnosis Actuate BUCK mode for approx. 40 s Normally, the output current will jump up to a high value (e.g. 100 A) and then slowly drop to the current specified value (e.g. 50 A) and then only change slowly and in small increments (video in attachment). In the event of this error cause, the DC/DC converter may react in two possible ways: 1) Despite displayed BUCK mode, the DC/DC converter does not provide any output voltage or output current (video in attachment). 2) The output voltage and output current may experience significant fluctuations/jumps (several 1-10 A) (video in attachment). Perform in XENTRY -> DC/DC converter N83/1 -> Special procedures -> "Evaluation of the HV resistance reduction of the DC/DC converter control unit". The special procedure compares the serial number of the installed DC/DC converter with the list of potentially affected parts. Depending on the result: If the serial number can be found in the list of potentially affected component parts, then replace the DC/DC converter. If the serial number cannot be found in the list of potentially affected parts but the problem described applies, then please open a TIPS case and forward to HQ.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI54.10-P-079534 | Service bulletin | Aug 8, 2025 | 11021802 | PDF, 39 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 Mercedes-Benz Redundant EQS 450; 2024 Mercedes-Benz Redundant EQS 450.
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 4 model years this bulletin names have filed 128 complaints with NHTSA since 2015. 35 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.
The contact owns a 2023 Mercedes-Benz EQS 580 4MATIC. The contact stated that while attempting to open the front driver’s side door, the door sensors failed to detect a hand and retracted independently and closed on the right index finger. Medical attention was not sought. The failure mileage was approximately 63,350
2023 Mercedes-Benz EQS · Electrical System · filed with NHTSA Sep 25, 2026 · ODI 11766894
My 2022 Mercedes-Benz EQS 450+ repeatedly showed "Active Brake Assist Functions Limited," "Active Emergency Stop Assist Inoperative," and Blind Spot Assist warnings, photographed by September 23, 2026. On September 24, I reported these issues and showed photos to an authorized dealer.
2022 Mercedes-Benz EQS · Electrical System · filed with NHTSA Oct 22, 2026 · ODI 11773071
On at approximately PDT, a 2024 Mercedes-Benz EQS SUV 450+ caught fire at an intersection in Irvine, California. The vehicle was being driven normally. It was NOT charging. It was NOT in a collision. It was stopped at the intersection when the fire began. There was no warning.
2024 Mercedes-Benz EQS · Electrical System · filed with NHTSA Apr 13, 2026 · ODI 11730842
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 group85 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 |
|---|---|---|---|
| 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… |
| 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… |
| LI82.85-P-079088 | Service bulletin | Aug 14, 2026 | Complaint The following most common complaints may be observed: • Brief connectivity interruptions when using Apple CarPlay over Wi-Fi • Aud… |
| LI54.65-P-080132 | Service bulletin | Aug 12, 2026 | Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist… |
| LI54.10-P-080880 | Service bulletin | Aug 12, 2026 | Complaint Customer Complaint: - AC charging is not possible. - The departure time, charging pause, location-based charging or target SOC lim… |
| LI54.10-P-080881 | Service bulletin | Aug 11, 2026 | Complaint AC and DC charging are not possible. The white LED on the charging inlet completely goes OFF after plugging in the charging cable.… |
| LI46.10-P-078012 | Service bulletin | Jul 17, 2026 | Complaint Hand detection system – malfunction / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist no… |
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 LI54.10-P-079534 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 LI54.10-P-079534 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 LI54.10-P-079534 cover?
The manufacturer filed it against 6 model years: 2025 Mercedes-Benz EQS, 2024 Mercedes-Benz EQS, 2023 Mercedes-Benz EQS, 2022 Mercedes-Benz EQS, 2023 Mercedes-Benz Redundant EQS 450, 2024 Mercedes-Benz Redundant EQS 450. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.