Mercedes-Benz bulletin LI77.21-P-075806
What it saysComplaint The sliding sunroof glass panel of the panoramic roof reverses during the closing process, either once or multiple times, without an entrapment (anti‑pinch) event being detected. NHTSA’s full summary ↓
Mercedes-Benz filed this with NHTSA as a service bulletin dated Apr 20, 2026, received Feb 3, 2023, about the visibility/wiper — 4 documents under this number. It names 6 model years (2023–2024). 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 communicationWhat it applies to, as the document itself states it — the build window in the manufacturer’s own words, read by machine from the PDF NHTSA serves. The build date is on the certification label in the driver’s door jamb; the dealer settles a borderline vehicle by its VIN.
Complaint The sliding sunroof glass panel of the panoramic roof reverses during the closing process, either once or multiple times, without an entrapment (anti‑pinch) event being detected. The concern may occur temporarily or repeatedly during normal closing operation. Cause The automatic reversing function of the panoramic roof is overly sensitive due to parameterization in combination with seal counter‑pressure. This condition can cause the roof to reverse even though no obstruction is present. Remedy Retrofit the vehicle to meet Cleanpoint status “Panoramic sliding sunroof glass panel reverses during closing without a pinch event.” The retrofit includes: • Hardware modification (installation of a cover rail / EPDM lip) • Corresponding software update for the panoramic roof control unit The prescribed retrofit steps must be performed in the specified sequence as outlined in this document. 1) Retrofit the EPDM lip onto the rear edge of the panoramic sliding roof panel: • Clean the underside of the rear edge of the sliding sunroof panel (marking, Figure 1) (e.g., isopropanol). • Subsequently install the cover rail on the underside of the sliding sunroof panel (Figure 2). - Distance from the cover rail to the rear edge of the sliding sunroof panel A = 5 mm - Distance from the cover rail to the right and left edges of the sliding sunroof panel B = 9 mm - Apply firm pressure by hand along the entire bonding surface of the COVER RAIL - The wider flange at the ends of the cover rail (see Figure 3) must point in the direction of travel 2) Submit an XSS Ticket with the following requests to add SA code O75 to the Vehicle Data Card • Enter code "O75" (Oscar 75) in Vehicle Documentation System (Vedok): • Add the following AO text to KG 78: AO code O75 added as specified in LI77.21-P-075806 (Version 7). 3) Install new software from the panoramic roof control unit (TSSR296, A98, PSD) and teach in the anti-pinch protection again: • Connect XENTRY Diagnosis. - always use the current XENTRY Diagnosis software release with all available add-ons. - Strict compliance with the operation steps in XENTRY Diagnosis is absolutely essential! - Ensure adequate power supply to the vehicle's on-board electrical system battery (greater than 12.5 V) using a battery charger. • Commission the panoramic roof control unit - To do this, select "A98 – control module 'panoramic sliding sunroo
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| LI77.21-P-075806 | Service bulletin | Apr 20, 2026 | 11031507 | PDF, 1,965 KB |
| LI77.21-P-075806 | Service bulletin | Oct 22, 2024 | 11009137 | PDF, 36 KB |
| LI77.21-P-075806 | Service bulletin | Jun 23, 2023 | 10238419 | not found |
| LI77.21-P-075806 | Service bulletin | Jan 20, 2023 | 10231034 | PDF, 35 KB |
What the document itself lists
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| A 294 782 06 00 | cover rail (model 294) 1 X | — | eBay Motors → |
| A 296 782 17 00 | cover rail (model 296) 1 X | — | eBay Motors → |
Read by machine from the document NHTSA serves (4 pages), read Sep 30, 2026. A part number is shown only where it matches Mercedes-Benz’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
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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.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
Find the sun/moon roof assembly for the 2024 EQE →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
Model years it names
Source: as the manufacturer filed themAlso filed against model years this site has no page for: 2023 Mercedes-Benz Redundant EQE 350 4MATIC; 2023 Mercedes-Benz Redundant EQS 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 4 model years this bulletin names have filed 129 complaints with NHTSA since 2015. 43 of them name Electrical System, Structure — 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.
The center console display (MBUX) on this 2023 EQS 450 4MATIC fails while the vehicle is in use. There is no warning lamp, chime or message first. Sometimes it flickers on and off; other times it goes fully blank and stays blank, unresponsive to touch. Owner video shows the display working and then completely blank 0.4 seconds later.
2023 Mercedes-Benz EQS · Visibility/Wiper · filed with NHTSA Sep 5, 2026
As i was driving on the interstate, i heard a gunshot-like explosion and the sunroof glass broke. Glass shards fell into the car. I had to slow down to 30 mph and exit the interstate. There was no obvious road debris or cars around me at the time of the incident. I drove the car to the dealership where it is for repair
2023 Mercedes-Benz EQE · Structure · filed with NHTSA Jul 8, 2026
The contact owns a 2023 Mercedes-Benz EQS 580 4MATIC. The contact stated that while attempting to open the front driver’s side door, the door sensors failed to detect a hand and retracted independently and closed on the right index finger. Medical attention was not sought. The failure mileage was approximately 63,350
2023 Mercedes-Benz EQS · Electrical System · filed with NHTSA Sep 25, 2026
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 visibility/wiper
Source: same model, same component group4 other manufacturer communications filed against these Mercedes-Benz models under the same component group (visibility/wiper), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| LI83.70-P-078292 | Service bulletin | Jun 16, 2026 | Complaint Red warning message in instrument cluster: "Towing not allowed, see Operator's Manual, consult workshop without starting the engin… |
| LI82.30-P-059239 | Service bulletin | May 19, 2026 | Complaint There are several types of complaint about noises or poor windshield wiper wiping performance: A: Wiper blades squeaking, chatteri… |
| LI83.30-P-079850 | Service bulletin | Jan 16, 2026 | Complaint Customer states the AC either does not cool/has poor performance or heat is insufficient. Cause Many possible root causes Remedy *… |
| LI83.30-P-079081 | Service bulletin | Apr 21, 2025 | Complaint Random heating of air conditioning system. Cause Temperature sensor in overhead control panel (OCP) delivering incorrect values: T… |
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 LI77.21-P-075806 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 LI77.21-P-075806 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.
Which vehicles does LI77.21-P-075806 cover?
The manufacturer filed it against 6 model years: 2024 Mercedes-Benz EQE, 2023 Mercedes-Benz EQE, 2024 Mercedes-Benz EQS, 2023 Mercedes-Benz EQS, 2023 Mercedes-Benz Redundant EQE 350 4MATIC, 2023 Mercedes-Benz Redundant EQS 450. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone. The document itself sets the build window: built on or before 8 Mar 2023; built on or before 9 Mar 2023; built on or before 1 Feb 2023 — the build date is on the certification label in the driver’s door jamb.