In March 2021, the Stuttgart-based automaker became aware of reports from the U.S. alleging loose window trim bars or trim that had detached from the vehicle while driving. Mercedes conducted an investigation, yet it ultimately couldn’t live up to its “best or nothing” slogan.
Retrieved parts were analyzed, and M-B determined that the window trim detachments were not the result of a product specification error or a design error. In an earlier safety recall, the design of the trim attachment had been modified to address the very issue that Mercedes-Benz is currently facing.
Analyses conducted from May 2021 to June 2021 determined that parts involved in the current incidents were not subject to the previous recall and had been produced after the design change was implemented. The German automaker conducted further analyses to determine the failure mechanism of the redesigned components. The conclusion? “Certain rework measures in the vehicle assembly plant may not have been performed according to current production specifications.” Said rework measures included the removal and reinstallation of the window trim bars at the assembly plant.
M-B added a manual pull check to the production process to mitigate this problem, revising the relevant work instructions for extra peace of mind. In July 2021, the documentation of the rework processes for different assembly lines was analyzed. M-B also initiated an effort “to determine if a particular worker or assembly group may have caused such deviation.”
Due to a lack of sufficient documentation of the rework processes, Mercedes-Benz couldn’t identify the specific factors responsible for the window trim bars coming loose or flying off the aforementioned vehicles.
Come December 2021, the company implemented yet another preventive measure consisting of an additional check with a pull check tool. A process quality audit was implemented in January 2022 to eliminate any installation process errors. Mercedes-Benz notes that a change in the production procedure ensures that this issue can no longer occur on vehicles produced from April 25th, 2022, onwards. Dealers will be instructed to check the installation of the trim bars on the rear-door windows. If necessary, dealers will rework them. Build dates for the affected vehicle population range from May 20th, 2019, through April 7th, 2022, and model years 2020 to 2022.
The nameplates included in this campaign are the Maybach GLS 600, AMG GLS 63, GLS 580, GLS 450, AMG GLE 63 S and 53, GLE 580, GLE 450, GLE 400 e, and GLE 350. Coincidentally, both the GLS full-size SUV and GLE mid-size SUV are produced for the U.S. market in Tuscaloosa, Alabama.