Mercedes-Benz bulletin NCU - 2025040001
Mercedes-Benz filed this with NHTSA as a emissions communication dated Feb 7, 2026, about the engine. It names 3 model years (2023). A emissions communication 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.
What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationMercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the engine control software might not meet current specifications. As a result, the diagnosis routine for monitoring the air-fuel ratio might not be activated as intended and a malfunction in the oxygen sensor could be erroneously detected causing the “check engine� Malfunction Indicator Lamp (‘MIL’) to illuminate. MBUSA will conduct a voluntary emissions recall. An authorized Mercedes-Benz dealer will update the engine control unit software.
Document filed under this number
| Document | Kind | Dated | NHTSA id |
|---|---|---|---|
| NCU - 2025040001 | Emissions | Feb 7, 2026 | 11028648 |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5; the full text comes from the manufacturer or a dealer. 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. Quote it 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.
Common questions
Source: NHTSA, 49 CFR 579.5Is Mercedes-Benz NCU - 2025040001 a recall?
No. A emissions communication 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 - 2025040001 repair free?
A emissions communication 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 - 2025040001 cover?
The manufacturer filed it against 3 model years: 2023 Mercedes-Benz C-Class, 2023 Mercedes-Benz G-Class, 2023 Mercedes-Benz SL-Class. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.