Mercedes-Benz bulletin LI 27.10-P-080851
What it saysComplaint Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situations. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Aug 29, 2026, received Sep 9, 2026, about the power train. It names 40 model years (2016–2025). 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 Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situations. May be most noticeable when transitioning from a coasting condition to accelerator pedal application. May occur in all drive modes. Cause Dual‑clutch transmissions (DCT) inherently exhibit more dynamic shifting behavior compared to other types of transmissions. This is due to the use of physical clutches for starting and gear changes. In certain situations, dynamic driving behavior can lead to a slight jerk sensation which is a normal technical characteristic of the transmission. A typical example is a "Change of Mind" situation: • The customer is coasting towards a red traffic light. • The traffic light turns green while the vehicle is still coasting. • The customer then presses the accelerator pedal. In these situations, a slight jerk may occur briefly because the transmission must quickly engage the appropriate gear and control the clutches accordingly. Since shift forks are responsible for engaging the gears during shifting, a slight shifting noise may also be noticeable. Please note driving programs S, S+, and M are designed to provide sportier vehicle behavior and are not optimized primarily for maximum comfort, so this operation may be more audible. Remedy Verify the customer's concern and confirm proper transmission operation. If no faults or abnormal operating conditions are identified by IPR (Intelligent Predictive Repair), no hardware replacement is necessary. Inform the customer that the transmission has been designed to provide direct gear engagement and responsive vehicle performance. Under certain operating conditions, brief shift sensations may be perceptible and are consistent with the operating characteristics of the dual‑clutch transmission
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI 27.10-P-080851 | Service bulletin | Aug 29, 2026 | 11037211 | PDF, 31 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 40 model years this bulletin names have filed 1,828 complaints with NHTSA since 2015. 82 of them name Power Train — 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.
Extended warrenty information mercedez benz has issued warrenty to that applie to condistions as listed above (exhaust valve, cyliner head ) back 08/04/2023 the car has in mercedez benz and have failed to pick on the extended warrrenty repairs and we now find out this cased more damage to the engine and needs to replace camshat and…
2020 Mercedes-Benz GLB-Class · Power Train · filed with NHTSA Jun 15, 2026 · ODI 11744345
The vehicle is shifting into neutral when putting it into drive. I was told the transmission valve body broke and transmission control unit for 9-speed transmission (VGS) has to be replaced. The fault codes include P073E00, gear cannot be engaged, and U012600, Communication with the steering column module has a malfunction.
2019 Mercedes-Benz GLE-Class · Power Train · filed with NHTSA Sep 19, 2026 · ODI 11765524
My 2018 Mercedes-Benz CLA250 4MATIC is experiencing a knocking noise from the rear differential at low speeds. The issue poses potential driving hazards, including possible loss of control and increased wear on drivetrain components. The noise may indicate a failing differential, which could suddenly fail while driving.
2018 Mercedes-Benz CLA-Class · Power Train · filed with NHTSA Sep 5, 2024 · ODI 11612753
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 power train
Source: same model, same component group57 other manufacturer communications filed against these Mercedes-Benz models under the same component group (power train), newest first. The eight newest are listed; the rest are on the Mercedes-Benz list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI27.00-P-073124 | Service bulletin | Sep 26, 2026 | Complaint Customer complaints relating to automatic transmission 725.0 (NAG3 Classic /9G‑TRONIC automatic transmission) and 725.1… |
| NCU - 2026080002 | Service campaign | Sep 25, 2026 | Mercedes-Benz AG, the manufacturer of Mercedes-Benz vehicles, has determined that on certain subject vehicles, the transmission control unit… |
| LI35.31-P-080353 | Service bulletin | Sep 14, 2026 | Complaint Whining / humming noises (described as foghorn‑like) from the drivetrain in the rear axle area during cornering. (figure 1) On the… |
| LI27.10-P-075869 | Service bulletin | Sep 14, 2026 | Complaint Only vehicles with a variable transfer case are affected. This can be identified through control unit N45 or N15/7 in the quick te… |
| NCU - 2026060005 | Service campaign | Sep 11, 2026 | Issue The transmission control unit (VGS) in the automatic transmission does not comply with our currently valid specifications in the vehic… |
| LI27.60-P-076554 | Service bulletin | Aug 26, 2026 | Complaint • Harsh 1‑2, 2‑3, and/or 3‑4 shift • Jerky shifting • Jolting when accelerating from stop Cause Insufficient software application… |
| LI27.19-P-080823 | Service bulletin | Aug 25, 2026 | Complaint Customers may report one or more of the following: • Transmission malfunction message • Check engine light illuminated • Shifts in… |
| PSL-NCU Return Parts 8/21 | Other | Aug 21, 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… |
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 LI 27.10-P-080851 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 LI 27.10-P-080851 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 LI 27.10-P-080851 cover?
The manufacturer filed it against 40 model years: 2022 Mercedes-Benz A-Class, 2021 Mercedes-Benz A-Class, 2020 Mercedes-Benz A-Class, 2019 Mercedes-Benz A-Class, 2018 Mercedes-Benz C-Class, 2017 Mercedes-Benz C-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.