Mercedes-Benz bulletin LI54.10-P-080199
What it saysComplaint For the potentially affected vehicles, excessively high aging of the battery was calculated at cold battery temperatures (<10°C) and the MIL activated accordingly, even though there is no corresponding high… NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Jan 14, 2026, about the electrical system. It names 23 model years (2021–2026). 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 communicationComplaint For the potentially affected vehicles, excessively high aging of the battery was calculated at cold battery temperatures (<10°C) and the MIL activated accordingly, even though there is no corresponding high level of aging physically. In this regard, the fault code P0A7F00 "The age limit of the hybrid/high-voltage battery module has been reached" is displayed in the N127 PTCU control unit and/or A66 battery module control unit (48 V battery). Cause Faulty computation of the age limit of the 48 V battery. Remedy Step 1: Software update of A66 battery module (48 V battery) Step 2: Perform reset routine: 2.1 Read out actual value 056 in A66 control unit (age limit SOH-R) a. If SOH-R <= 125%: Delete fault memory in PTCU control unit (N127) and 48 V battery (A66). Process ended. b. If SOH-R > 125%: Drive for 60 min to add SOH-R value. 2.2 Read out actual value 056 in A66 control unit (age limit SOH-R) a. If SOH-R <= 125%: Delete fault memory in PTCU control unit (N127) and 48 V battery (A66). Process ended. b. If SOH-R > 125%: Park vehicle > 12 hours in the workshop at a warm ambient temperature > 15°C, then drive for 60 min. 2.3 Read out actual value 056 in A66 control unit (age limit SOH-R) a. If SOH-R <= 125%: Delete fault memory in PTCU control unit (N127) and 48 V battery (A66). Process ended. b. If SOH-R > 125%: Create TIPS case
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI54.10-P-080199 | Service bulletin | Jan 14, 2026 | 11027656 | PDF, 37 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: 2024 Mercedes-Benz AMG C63 S E; 2024 Mercedes-Benz AMG C63 S E 4MATIC+; 2023 Mercedes-Benz AMG E53E; 2023 Mercedes-Benz AMG S 63 E 4MATIC+; 2024 Mercedes-Benz AMG S 63 E 4MATIC+; 2026 Mercedes-Benz E53 E 4MATIC+ ALL-Terrain.
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 17 model years this bulletin names have filed 359 complaints with NHTSA since 2015. 133 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.
1. Car's computer abruptly shutdown all controls/systems when lightly applying brake to stop at yellow light. Lost Total control of car, steering locked, 4 wheel drive locked all wheels, park brake inoperable, doors locked, windows would not operate, key fob was made inoperable, HVAC was inoperable, no lights worked except for Emerg…
2026 Mercedes-Benz E-Class · Electrical System · filed with NHTSA Jun 29, 2026 · ODI 11747174
The digital instrument cluster and center infotainment display screen went completely black and blank while the vehicle was in motion. This immediate failure blinded the driver to critical safety telemetry, including the current vehicle speed, gear positioning, and active safety warning telltales, creating an immediate, severe crash…
2025 Mercedes-Benz E-Class · Electrical System · filed with NHTSA Jun 23, 2026 · ODI 11746077
On Sunday, XXX at approximately 5:30 PM, I entered the parking lot of a Staples store at , in my 2025 Mercedes Benz AMG GLC 43 SUV. It was daylight and the weather was clear. There was no wind and the temperature was in the low 80s. I drove down a parking aisle and slowed down to make a right turn into an open parking space.
2025 Mercedes-Benz GLC-Class · Electrical System · filed with NHTSA Sep 21, 2026 · ODI 11765946
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 group190 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… |
| 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… |
| LI82.60-P-079747 | Service bulletin | Sep 4, 2026 | Complaint The Apple Music app is no longer available in the head unit apps menu after updating the software of the… |
| NCU - 2026080001 | Service campaign | Aug 15, 2026 | Issue Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year 2027 S-Class (223 platform) ve… |
| 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… |
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-080199 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-080199 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-080199 cover?
The manufacturer filed it against 23 model years: 2026 Mercedes-Benz C-Class, 2025 Mercedes-Benz C-Class, 2024 Mercedes-Benz C-Class, 2023 Mercedes-Benz C-Class, 2022 Mercedes-Benz C-Class, 2026 Mercedes-Benz E-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.