Mercedes-Benz service campaign NCU - 2026040007
What it saysMercedes-Benz AG (MBAG), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (MY) 2024 CLA (118 platform) vehicles, the engine electronics control unit software does not correspond… NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service campaign dated May 8, 2026, about the engine. It names 1 model year (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 (MBAG), the manufacturer of Mercedes-Benz vehicles, has determined that on certain Model Year (MY) 2024 CLA (118 platform) vehicles, the engine electronics control unit software does not correspond to the current production specifications. There is a possibility that the Air Fuel Imbalance (AFIM) diagnosis for the air/fuel ratio could fail. MBUSA will conduct a service campaign. An authorized Mercedes-Benz dealer will update the software of the engine electronics control unit in the affected vehicles.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| NCU - 2026040007 | Service campaign | May 8, 2026 | 11032520 | PDF, 437 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 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 1 model year this bulletin names have filed 2 complaints with NHTSA since 2015. 1 of them name 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.
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 group12 other manufacturer communications filed against the Mercedes-Benz CLA-Class 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 7/24 | Other | Jul 24, 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… |
| CL - 2026010005 | Other | Apr 18, 2026 | Dear Mercedes-Benz Owner: On behalf of Mercedes-Benz USA, LLC (“MBUSA”), thank you for being a part of the Mercedes-Benz family. We hope tha… |
| Emissions - 2026010005 | Emissions | Apr 2, 2026 | Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles equipped with M139 gasoline en… |
| 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… |
| NCU - 2026020005 | Service campaign | Feb 28, 2026 | Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the control unit software for… |
| LI01.30-P-075439 | Service bulletin | Nov 5, 2025 | Complaint Customer may complain of a CEL on in the instrument cluster, rough running, trouble starting, issues with ECO stop/ start or a com… |
| LI20.10-P-076206 | Service bulletin | Oct 13, 2025 | Complaint Customer states that the CEL is lit in the instrument cluster. Various codes may be active/stored: Stored in N3/10 in model series… |
| LI07.70-P-078078 | Service bulletin | Sep 16, 2024 | Complaint Check engine light on. Fault code P207273 - "Throttle actuator valve is blocked due to ice" stored. Engine may crank and not start… |
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 - 2026040007 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 - 2026040007 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 - 2026040007 cover?
The manufacturer filed it against 1 model year: 2024 Mercedes-Benz CLA-Class. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.