Investigations
Front Roof Panel Detachment
NHTSA Preliminary Evaluation PE21001 — closed, opened 2021-01-08 and involving the MERCEDES-BENZ MERCEDES BENZ.
NHTSA investigation PE21001 is a Preliminary Evaluation opened on 2021-01-08 and currently closed. The subject of record is MERCEDES-BENZ MERCEDES BENZ, which places this file inside the Office of Defects Investigation queue for MERCEDES-BENZ. Latest activity on this investigation was logged on 2021-10-14 — NHTSA updates that field whenever an Information Request goes out, a supplement is filed, or a status change is recorded in the public docket.
A Preliminary Evaluation like PE21001 is the entry point of the federal defect-investigation process. NHTSA engineers scan complaint databases, field reports, and manufacturer data to decide whether an Engineering Analysis is warranted, whether a voluntary recall is already sufficient, or whether the pattern does not rise to a defect finding.
Investigators summarized the matter as follows: "On January 8, 2021, after ongoing review with Mercedes Benz, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) opened PE21-001 to assess allegations of front roof panel deta..." Investigations are the early-warning layer of the federal auto-safety system, sitting upstream of formal recalls and defect orders. Whether this one closes without action or escalates into an Engineering Analysis, the full history stays in the ODI archive so researchers, litigators, and buyers can pull the paper trail at any time. Related MERCEDES-BENZ files, listed below, give context on whether this is an isolated concern or part of a broader pattern across the brand.
Investigation Summary
On January 8, 2021, after ongoing review with Mercedes Benz, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) opened PE21-001 to assess allegations of front roof panel detachments while driving at highway speeds in certain 2015 Mercedes-Benz (Mercedes) C-Class vehicles. The subject front roof panel is a stationary panel composed of polycarbonate and is attached to the vehicle via adhesive at the time of manufacture. The panel is found on subject vehicles equipped with panoramic sunroofs. Over time, the subject panels may exhibit cosmetic degradation leading to replacement of the panel, a procedure which entails: removal of the old panel and adhesive, site preparation, and installation of a replacement panel with new adhesive. The consumer complaints that prompted the opening of PE21-001 all described detachments of front roof panels that had been replaced after the vehicle was put into service. Mercedes' internal investigation identified a broader scope of affected vehicles (2014-2020 CLA, GLA, C, S, GLC, and GLE class) and found the following potential service procedure- related causes of front roof panel detachments: - Improper surface pretreatments such as the use of the wrong primer or cleaner or scoring of the surface; or - Use of the incorrect adhesive. These conditions lead to a front roof panel bond that, even if sound at the time of repair, cannot maintain its strength over time and environmental exposure. Mercedes updated its service and parts ordering systems to reinforce the proper use of specified kits and procedures via webinars, shop foreman meetings, and explicit reference to the risks incurred by diverging from the repair procedures. Mercedes is also furnishing parts ordering assistance, and will hold dealerships accountable for improper repairs. ODI's analysis of the ten complaints it has received from the public (VOQ's) and MBUSA's complaint data submitted in response to the information request lette
About This Investigation Type
A Preliminary Evaluation (PE) is the first phase of NHTSA's investigation process. It is opened when the agency identifies a potential safety defect pattern, usually triggered by consumer complaints, manufacturer reports, or field monitoring. During a PE, NHTSA gathers information to determine whether a formal engineering analysis is warranted.
Other MERCEDES-BENZ Investigations
Malfunction Indicator Light / No-Start
C300 Wrist-pin allegation
Vehicle Rolls Away While in Park
Rear brake line failure
Recall Administration Concerns
Data from NHTSA Office of Defects Investigation. Cross-references: NHTSA recall campaign API and NHTSA FARS where fatality records overlap. PlainCars does not rate or recommend vehicles. Learn more.
Read our methodology — how this data is sourced, computed, and verified.