Mercedes-Benz service campaign NCU - 2026010004
What it saysAlways use the latest XENTRY Diagnosis software release with all available add-ons. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service campaign dated Jul 27, 2026, received Jan 22, 2026, about the engine — 2 documents under this number. It names 2 model years (2020–2021). 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 communication• Always use the latest XENTRY Diagnosis software release with all available add-ons. • Make sure to follow the operation steps exactly as described in XENTRY Diagnosis! • Use a battery charger to ensure sufficient power supply of the vehicle on-board electrical system battery (greater than 12.5 V). • If XENTRY Diagnosis is already connected to the vehicle, start with operation step 2. If two or more software updates or SCN coding’s are performed during one workshop visit or SCN coding operations are performed, operation items 02-4762 and 02-5058 must only be invoiced once for each workshop order! Work Procedure: 1. Connect XENTRY Diagnosis. 2. Update engine electronics (ME) control unit software. To do so, select menu item "Quick test view → N3/10 - Engine electronics 'MED40' for combustion engine 'M274' (ME) → Adaptations → Control unit update → Update of control unit software". Then follow the user guidance in XENTRY Diagnosis. 3. Disconnect XENTRY Diagnosis.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| NCU - 2026010004 | Service campaign | Jul 27, 2026 | 11035270 | PDF, 145 KB |
| NCU - 2026010004 | Service campaign | Jan 23, 2026 | 11027757 | PDF, 397 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 2 model years this bulletin names have filed 106 complaints with NHTSA since 2015. 54 of them name Engine, 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.
Vehicle: 2021 Mercedes-Benz E350 Sedan (W213) VIN: While operating the vehicle, the diagnostic system displayed the fault code P240200 related to the Evaporative Emission Control System (EVAP). The warning message indicated a “positive short circuit” in the fuel vapor leak diagnosis pump control circuit.
2021 Mercedes-Benz E-Class · Electrical System · filed with NHTSA May 8, 2026 · ODI 11736678
Engine keeps having a misfire that Mercedes put a TSB out for and once the misfire happen I cause the vehicle to go in a limp mode which causes the vehicle to loose power happened to me in the freeway. The car had 54K miles and Mercedes refused to repair the issue as the engine part failure isn’t common
2021 Mercedes-Benz E-Class · Engine · filed with NHTSA Dec 27, 2025 · ODI 11707258
Engine failure needs cylinder head replaced which is very common amongst this car. Same make and model is covered under warranty but mine has a different engine that isn't covered. These cars were made during covid and have faulty parts
2020 Mercedes-Benz GLC-Class · Engine · filed with NHTSA May 2, 2024 · ODI 11586626
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 group39 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 |
|---|---|---|---|
| LI18.00-P-073137 | Service bulletin | Sep 26, 2026 | Complaint Sporadic warning message in instrument cluster "Engine oil pressure stop switch off vehicle" (or similar) is shown in red on vehi… |
| LI20.10-P-075374 | Service bulletin | Sep 17, 2026 | Complaint Red coolant warning in instrument cluster. Fault codes U019F00 or U019F87 current/stored in MRG1 control unit. Cause Various cause… |
| 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… |
| 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 - 2026010004 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 - 2026010004 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 - 2026010004 cover?
The manufacturer filed it against 2 model years: 2021 Mercedes-Benz E-Class, 2020 Mercedes-Benz GLC-Class. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.