Mercedes-Benz bulletin LI27.60-P-079968
What it saysComplaint A harsh 5-4 downshift can be felt during deceleration while braking or coasting. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Nov 5, 2025, received Nov 7, 2025, about the power train. It names 21 model years (2020–2026). 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 A harsh 5-4 downshift can be felt during deceleration while braking or coasting. It may be mistaken for a hard brake engagement Cause Poor learning of brake B06 adaptation values over time. Remedy Short-term remedy: 1. Perform IPR and follow the instructions. 2. Perform resetting of deceleration values (VGS > Special Procedures > Special procedure > Resetting learned values Deceleration mode) 3. Perform standard adaptation 4. Reevaluate the concern and release vehicle if no longer present Note: ALL steps (resetting learned values and standard adaptation) must be completed to fully resolve the complaint. Long-term measure: Aftersales software is currently in development.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI27.60-P-079968 | Service bulletin | Nov 5, 2025 | 11025150 | PDF, 216 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; 2023 Mercedes-Benz AMG E53E; 2023 Mercedes-Benz CLE 300; 2023 Mercedes-Benz CLE 450.
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 17 model years this bulletin names have filed 665 complaints with NHTSA since 2015. 29 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.
Vehicle experiences a severe, abrupt jerk/jolt during deceleration around the 5th-to-4th gear downshift. The issue occurs consistently when slowing down. Dealership verified the condition on Repair Order #1906625 and confirmed a transmission flaw. Dealer stated software is required from the manufacturer with no ETA for release.
2025 Mercedes-Benz GLC-Class · Power Train · filed with NHTSA Aug 6, 2026 · ODI 11755359
While at a stop with foot on brake, the vehicle surges forward powerfully making a loud noise despite having foot on brake. Forcefully pushing on brake pedal harder eventually stops the car. Most recent time the display screen showed "Transmission Deactivated". Dealership drove car once but did not perform service inspection.
2026 Mercedes-Benz GLC-Class · Power Train · filed with NHTSA Jan 16, 2026 · ODI 11711555
After being parked for several days at the airport, the vehicle turned on, but would not start. The instrument cluster had the following message, “Service required do not change transmission position”. I contacted Mercedes road side assistance who cannot access this parking level.
2025 Mercedes-Benz E-Class · Power Train · filed with NHTSA May 16, 2026 · ODI 11738284
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 group46 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… |
| LI 27.10-P-080851 | Service bulletin | Aug 29, 2026 | Complaint Intermittent shift feel or thud/clunk noise perceived, such as a brief jerk or transmission reaction during certain driving situat… |
| 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… |
| LI27.00-P-075630 | Service bulletin | Aug 5, 2026 | Complaint This document is intended as a pre-case diagnostic reference for transmission related concerns. It will also ensure that if a case… |
| LI27.00-P-080840 | Service bulletin | Aug 4, 2026 | Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid specification ATF 236.17 due to a global su… |
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 LI27.60-P-079968 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 LI27.60-P-079968 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 LI27.60-P-079968 cover?
The manufacturer filed it against 21 model years: 2025 Mercedes-Benz C-Class, 2024 Mercedes-Benz C-Class, 2023 Mercedes-Benz C-Class, 2022 Mercedes-Benz C-Class, 2024 Mercedes-Benz CLE-Class, 2025 Mercedes-Benz E-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.