{"nhtsa_id":11031867,"type":"service_bulletin","type_name":"Service bulletin","date_added":"2026-05-01","date":"2026-04-30","document_id":"LI77.21-P-080503","mfr_campaign":null,"replaces":null,"component":"ELECTRICAL SYSTEM","mfr_system":null,"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. In combination with one, serval, or all of the following Fault Codes stored in the panoramic roof control unit (PSD, A98, TSSR254): • B184954 • B184955 • B1E7554 • B1E7555 Note: Please see LI77.21-P-075807 for complaints of the sliding sunroof panel of panoramic sliding sunroof reverses (temporarily, once, multiple times) during closing process without an entrapment event 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).","document":{"url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11031867-0001.pdf","alternate_url":"https://static.nhtsa.gov/odi/tsbs/2026/MC-11031867-9999.pdf","confirmed":false},"url":"https://open.wenmarpro.com/bulletins/11031867","components":[{"id":"electrical","name":"Electrical system","parent":null}],"codes":["B1849","B1E75"],"topics":[],"vehicles":[{"make":"MERCEDES-BENZ","model":"AMG GLC43","year_from":2024,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43 4MATIC","year_from":2024,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC43 4MATIC COUPE","year_from":2024,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E","year_from":2024,"year_to":2025,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E 4MATIC+","year_from":2025,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"AMG GLC63 S E 4MATIC+ COUPE","year_from":2025,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300","year_from":2020,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300 4MATIC","year_from":2023,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300 4MATIC COUPE","year_from":2024,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 300 COUPE","year_from":2024,"year_to":2024,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC 350 E 4MATIC","year_from":2025,"year_to":2026,"match":null,"vehicle_ids":[]},{"make":"MERCEDES-BENZ","model":"GLC43 4MATIC COUPE","year_from":2026,"year_to":2026,"match":null,"vehicle_ids":[]}],"as_of":"2026-10-19","note":"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.","attribution":[]}