While everyone and their dog is preparing for New Year’s Eve fireworks and socializing with our loved ones, Merc is busy filing recalls with the federal watchdog. The latest campaign involves model year 2021 through 2024 vehicles from the C-Class, E-Class, CLS, S-Class, GLC, GLE, GLS, G-Class, GT, and SL lines, namely vehicles equipped with fuel pumps manufactured by Hyundam Industrial Co.

An estimated 79,676 vehicles require new fuel pumps, with said vehicles ranging from the 2022 to 2024 model year Mercedes-Benz C 300 to AMG versions, including the 63 series. What is the problem with the suspect fuel pumps? According to documents published by the NHTSA, the supplier identified a deviation in the production process of a sub-supplier. The fuel pump impeller might not meet material requirements, a condition that’s eerily similar to Honda’s recent mammoth recall involving 2.5 million vehicles equipped with Denso pumps.

The impeller is prone to deform, therefore leading to mechanical resistance. Mercedes-Benz AG claims that – in some instances – the mechanical resistance might result in the fuel pump shutting down while driving. Before the fuel pump goes kaput, drivers may be made aware of the impending shutdown by a rough-running engine or a malfunction indicator lamp/warning message on the instrument cluster.

Merc started investigating field reports alleging inconsistent power delivery in June 2022, with the first reports originating from outside the United States market. Stuttgart’s favorite son retrieved fuel pumps from the field, which – over the next several months – were analyzed in coordination with Hyundai Industrial Co. and relevant sub-suppliers.

In December 2022, the German automaker and Hyundam identified an irregularity in raw material batches at one sub-supplier. The following month, Hyundam was required to change its fuel pump impeller raw material sub-supplier. Merc also required the changing of the injection molding process at the injection molding supplier, as well as additional quality controls within the supplier chain.

2,031 warranty claims, field reports, and service reports later, Mercedes recalled potentially affected vehicles in June 2023. Be that as it may, Mercedes-Benz AG didn’t investigate this matter properly. In July 2023, the automaker determined that additional batches of raw material may have ended up as fuel pump impellers in tens of thousands of vehicles that were not included in the original recall’s population.

Between May 2022 and November 2023, the automaker received a further 1,901 claims and reports on top of the 2,031 mentioned earlier. Said 2,031 were received between August 2021 and May 2023. Thankfully for affected owners and Merc’s legal department, the automaker isn’t aware of any crashes, injuries, or property damage related to this issue.

Dealers have already been informed about the second recall, which covers no fewer than 14 fuel pump variants. Obviously enough, service techs will replace iffy pumps with properly manufactured fuel delivery units at no charge whatsoever to owners.

Owner notifications will be mailed in February 2024. For the time being, it would be wise to run the 17-character VIN on the NHTSA’s website to determine whether your Mercedes is indeed affected or not.

Extracted in full from:  https://www.autoevolution.com/news/mercedes-fuel-pump-issue-prompts-recall-almost-80000-vehicles-affected-226818.html