Mercedes-Benz bulletin LI27.60-P-078998
What it saysComplaint A noticeable jerk or jolt from the transmission occurs in electric driving mode (E mode), between 20-40 mph. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Feb 13, 2026, received Mar 11, 2025, about the power train — 2 documents under this number. It names 15 model years (2023–2026). 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 noticeable jerk or jolt from the transmission occurs in electric driving mode (E mode), between 20-40 mph. Concern is mainly felt when coasting. Cause Parameters of the 5–4 neutral downshift (the shift method used in EV operation). Remedy This shift concern is considered normal for vehicles with this drivetrain. Hardware replacement does not change the root cause of the concern, as the observed shift behavior is characteristic of normal system function rather than a component‑related fault. The following adaptations may improve the shift quality: 1. Check transmission oil level (transmission oil temperature > 60°C) 2. Flush valves via Xentry procedure 3. Perform standstill adaptation 4. Perform driving adaptations for the 5–4 shift while following the below parameters: - Drive program: Slippery - Display torque in the instrument cluster - Do not shift using the paddles During coasting downshift 5-4: - Torque between –90 and –15 Nm (-66 and -11 ft-lb) - Maximum engine speed: 1,300 rpm
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI27.60-P-078998 | Service bulletin | Feb 13, 2026 | 11028812 | PDF, 36 KB |
| LI27.60-P-078998 | Service bulletin | Mar 7, 2025 | 11015550 | PDF, 35 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; 2024 Mercedes-Benz AMG C63 S E 4MATIC+; 2024 Mercedes-Benz AMG GT63 S E; 2024 Mercedes-Benz AMG GT63 S E Performance; 2026 Mercedes-Benz AMG GT63 S E Performance 4MATIC+; 2023 Mercedes-Benz AMG S 63 E 4MATIC+; 2024 Mercedes-Benz AMG S 63 E 4MATIC+.
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 8 model years this bulletin names have filed 71 complaints with NHTSA since 2015.
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
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 group48 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… |
| 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… |
| 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-078998 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-078998 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-078998 cover?
The manufacturer filed it against 15 model years: 2025 Mercedes-Benz AMG GT, 2026 Mercedes-Benz C-Class, 2025 Mercedes-Benz C-Class, 2026 Mercedes-Benz GLC-Class, 2025 Mercedes-Benz GLC-Class, 2025 Mercedes-Benz S-Class and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.