Mercedes-Benz service campaign NCU - 2025040004
What it saysMercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the engine control unit software may not correspond with current production specifications. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service campaign dated Apr 17, 2025, received Apr 24, 2025, about the engine. It names 7 model years (2023–2024). A service campaign is not a safety recall — there is no NHTSA campaign number and no federal requirement — but it is usually work the manufacturer pays for on the vehicles it names; the dealer checks the VIN against the manufacturer’s list.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the engine control unit software may not correspond with current production specifications. There is a possibility that the dynamic driving profile may not be accurately calculated, which could possibly lead to an unsuccessful diagnostic routine for the lambda sensors. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the engine control unit software.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| NCU - 2025040004 | Service campaign | Apr 17, 2025 | 11017220 | PDF, 339 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 SL53E; 2024 Mercedes-Benz AMG SL63 S E.
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 42 complaints with NHTSA since 2015. 17 of them name Electrical System, Engine — 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.
My mom and I were in her car brand new Mercedes adaptive cruise was on the car started to act up with all the warning lights again, which shut all safety systems down air back seatbelts, adaptive cruise, Tronics and the engine wall between 18 wheeler and the freeway wall slammed the vehicle into the freeway hall causing about $5000 worth…
2023 Mercedes-Benz SL-Class · Electrical System · filed with NHTSA Jan 21, 2025 · ODI 11637467
Driving a 2024 mercedes c300 on the florida turnpike in the left lane at 70 MPH the engine suddenly slowed down. While the vehicle slowed in heavy traffic I was able to merge to the outside lane where it stopped. I called mercedes emergency who suggested waiting a while and try starting the vehicle .
2024 Mercedes-Benz C-Class · Engine · filed with NHTSA Jul 19, 2026 · ODI 11751377
Dashboard reading incorrectly. Blackout screen while driving. Mileage incorrectly reading. Speed limit incorrectly reading while driving the Dashboard pick up the undercarriage camera. The electricity on the car keep popping up.
2024 Mercedes-Benz C-Class · Electrical System · filed with NHTSA Aug 4, 2026 · ODI 11754852
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 engine
Source: same model, same component group45 other manufacturer communications filed against these Mercedes-Benz models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| PSL-NCU Return Parts 8/14 | Other | Aug 15, 2026 | Dear Mercedes-Benz USA Dealers, The part numbers listed in the chart below should no longer be installed, and any existing stock must be ret… |
| LI01.20-P-080884 | Service bulletin | Aug 12, 2026 | Complaint Oil leaks found on M176 or M177 engines diagnosed to be from the cylinder head cover area Cause Unknown (under investigation) Reme… |
| LI07.10-P-080384 | Service bulletin | Aug 7, 2026 | Complaint Customer reports Check Engine Light with possible loss of power concern. The Following DTC's are present • P210185 - The throttle… |
| LI20.10-P-072886 | Service bulletin | Jul 24, 2026 | Complaint Check Engine Light ON with DTC P012800 "The Coolant Temperature is Below the Specified Temperature" active and/or stored in the ME… |
| Emissions - 2024100016 | Emissions | Jul 24, 2026 | Mercedes-Benz AG (“MBAG”), the manufacturer of Mercedes-Benz, has determined that on certain MY 2019-2021 C-Class, G-Class, GLC, GT, S-Class… |
| LI07.70-P-078293 | Service bulletin | Apr 9, 2026 | Complaint Customer states CEL ON with no drivability complaints Cause The following DTC is active and/or stored in the ME (N3/10) due to sig… |
| LI01.30-P-072328 | Service bulletin | Mar 27, 2026 | Complaint -Check engine light illuminated. -Engine runs rough. -Poor shifting or jerking when accelerating. -Fault codes stored related to m… |
| CL - EW M157 | Other | Mar 27, 2026 | Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfacti… |
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 NCU - 2025040004 a recall?
No. A service campaign 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 NCU - 2025040004 repair free?
A service campaign is usually paid by the manufacturer on the vehicles it names, within the terms and time limit the document sets; the dealer checks the VIN against the manufacturer’s list.
Which vehicles does NCU - 2025040004 cover?
The manufacturer filed it against 7 model years: 2024 Mercedes-Benz C-Class, 2023 Mercedes-Benz C-Class, 2024 Mercedes-Benz SL-Class, 2023 Mercedes-Benz SL-Class, 2024 Mercedes-Benz AMG C63 S E, 2024 Mercedes-Benz AMG SL53E and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.