# Service bulletin LI77.21\-P\-075807

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: 11013336
- Published by NHTSA: 2025\-01\-31
- Manufacturer's number: LI77.21\-P\-075807
- Manufacturer's date: 2025\-01\-23
- NHTSA component: VISIBILITY/WIPER; ELECTRICAL SYSTEM; STRUCTURE:BODY

## NHTSA's summary

Complaint Sliding sunroof panel of panoramic sliding sunroof reverses \(temporarily, once, multiple times\) during closing process without entrapment event: a\) from tilt position b\) from sliding position Cause a\) Sensitive parameterization of the automatic reversing function of the panoramic roof b\) Sluggish operation through tolerances of various component parts in the roof mechanism, in particular, at higher temperatures Remedy a\) Leave the sliding sunroof panel of the panoramic roof in the rear sliding position \(fully open position\) for at least 30 minutes \(or overnight if necessary\), then perform commissioning of the panoramic roof control unit \(PSD, A98, TSSR254\) \(CP series: New software/parameter data set for X254 since 12.10.2023\) b\) Perform commissioning of the panoramic roof control unit \(PSD, A98, TSSR254\) \(CP series: New software/parameter data set for X254 since 23.09.2023\) Reference to escalation closing during reversing processes \(also described in Operator’s Manual\), if vehicle in customer possession \(see Video\_1\): If the panoramic roof blocks up when closing and then opens again slightly \(reversing process\): Immediately after automatic reversing, wipe forwards on the control panel of the overhead control panel and hold until the panoramic roof is closed. The panoramic roof is closed with greater closing force. If the panoramic roof blocks up again and then opens again slightly \(reversing process\): repeat previous step. The panoramic roof is closed again with greater closing force.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11013336-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11013336-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Body and frame, Electrical system, Glass, wipers and mirrors, Wipers and washers

## Vehicles listed

- 2020 to 2024 MERCEDES\-BENZ AMG GLC43
- 2020 to 2022 MERCEDES\-BENZ AMG GLC63
- 2020 to 2023 MERCEDES\-BENZ AMG GLC63 S
- 2024 MERCEDES\-BENZ AMG GLC63 S E
- 2020 to 2024 MERCEDES\-BENZ GLC 300
- 2024 MERCEDES\-BENZ GLC 300 COUPE
- 2025 MERCEDES\-BENZ GLC 300E
- 2020 MERCEDES\-BENZ GLC 350
- 2020 to 2021 MERCEDES\-BENZ GLC 350 E
- 2025 MERCEDES\-BENZ GLC 350 E 4MATIC

JSON: [/v1/bulletins/11013336](/v1/bulletins/11013336)

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