Service bulletin LI77.21-P-080503
A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.
| Type | Service bulletin |
|---|---|
| NHTSA id | 11031554 |
| Published by NHTSA | 2026-04-25 |
| Manufacturer's number | LI77.21-P-080503 |
| Manufacturer's date | 2026-04-24 |
| NHTSA component | VISIBILITY/WIPER |
NHTSA's summary
Complaint The panoramic sliding sunroof operates in a stepped movement. The panoramic roof becomes denormalized without an apparent reason (not directly after control unit replacement). Automatic operation of the glass panel and roller sunblind is not possible; only tip‑mode operation is available. Cause Resetting the panoramic roof control unit (PSD – A98 / TSSR254) can lead to loss of normalization. The root cause for the control unit reset is currently under investigation. Remedy Contribution to cause analysis: • Print the attached document “Panoramic Roof Customer Questionnaire.” • Complete the questionnaire together with the customer. • Open a TIPS case and attach the completed questionnaire. • Submit the TIPS case to the Body / Chassis / Entertainment inbox. Repair: Perform Initial Start‑Up of the panoramic roof control unit (PSD – A98 / TSSR254).
The document
The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.
Components
Glass, wipers and mirrors, Wipers and washers
| MERCEDES-BENZ AMG GLC43 | 2024 |
|---|---|
| MERCEDES-BENZ AMG GLC43 4MATIC | 2024 to 2026 |
| MERCEDES-BENZ AMG GLC43 4MATIC COUPE | 2024 to 2025 |
| MERCEDES-BENZ AMG GLC63 S E | 2024 to 2025 |
| MERCEDES-BENZ AMG GLC63 S E 4MATIC+ | 2025 to 2026 |
| MERCEDES-BENZ AMG GLC63 S E 4MATIC+ COUPE | 2025 to 2026 |
| MERCEDES-BENZ GLC 300 | 2023 to 2026 |
| MERCEDES-BENZ GLC 300 4MATIC | 2023 to 2026 |
| MERCEDES-BENZ GLC 300 4MATIC COUPE | 2024 to 2026 |
| MERCEDES-BENZ GLC 300 COUPE | 2024 |
| MERCEDES-BENZ GLC 350 E 4MATIC | 2025 to 2026 |
| MERCEDES-BENZ GLC43 4MATIC COUPE | 2026 |
Listing a model year does not mean every vehicle of it is concerned: the document says which.