In the first instance, Merc hypothesized that the electronic stability program – otherwise known as electronic stability control – pump motor is the culprit. However, the in-depth analysis didn't reveal any defect whatsoever. Mercedes couldn't identify the failure mechanism either. As a result, further investigations were carried out between February 2022 and April 2022. The company used simulations of field conditions to trigger the aforementioned failure. Said tests revealed that certain driving conditions may interfere with the ESP software at the beginning of a given driving cycle.
Said interference results in the erroneous detection of a fault condition with the ESP's pump motor power supply. Given these circumstances, Mercedes-Benz AG decided to update the faulty software back in July 2022. For whatever reason, Merc started using the updated software on May 1, 2023.
That's 10 months of faffing about, which is unacceptable for the automaker that prides itself on delivering "the best or nothing." Merc is aware of a whopping 96 field reports in the US alone, with receipt dates ranging from March 23, 2022 through May 12, 2023. On the upside, no crashes or injuries have been caused by said issue. Affected vehicles include the 297 and 223 series, namely the EQS and S-Class sedans.
The list begins with the 2022 model year EQS 450 and EQS 580, whereas the remainder comprises the 2023 model year Mercedes-Benz S 580 e, Mercedes-Maybach S 580, and Mercedes-Maybach S 680. Affected vehicles were made in the period between April 20, 2021 and February 27, 2023.
Dealers have already been instructed to update the electronic stability program software. As per the attached report, said update bears two part numbers. In all likelihood, one part number is for the EQS and the other is for the S-Class. Known owners will be notified by first-class mail before July 18.
Codenamed V297, the EQS five-door liftback is Merc's first electric vehicle built around an EV-specific platform. It's also the first electric vehicle from the Mercedes-AMG performance brand, albeit the EQS 53 4MATIC+ is a bit lacking in the aural pleasure department. The W223, by comparison, is available with six-, eight-, and twelve-cylinder lumps. Only the Maybach-branded S 680 comes with a V12 engine. The range-topping specification kicks off at a whopping $229,000.