BMW is recalling almost 3,500 EVs due to issues with the artificial sound generator that’s meant to warn people when the vehicles are backing up or traveling at low speeds. According to the National Highway Traffic Safety Administration (NHTSA) website, the recall applies to some 2022 and 2023 BMW i4 and iX models.

Federal safety standards require EVs or hybrids to make a certain amount of noise so that pedestrians can tell that there’s a car coming. Since electric motors are generally pretty quiet, especially at low speeds (the tires will likely be pretty loud on their own when you’re going faster), auto manufacturers usually have their cars make artificial sounds. That often ends up being a futuristic hum or whir; for performance models of the i4, BMW even worked with Hans Zimmer to create a sound meant to evoke the idea of a gas engine.

The problem with the affected cars is that the system that makes the noise doesn’t always work. According to the recall, “the artificial sound generator control unit may experience a fault and fail to generate the external pedestrian warning sound.”

It’s apparently fixable via a software update, though it doesn’t seem like BMW is taking the Tesla approach of doing it over the air. The NHTSA’s notice says that “dealers will update the external artificial sound generator software” for free, implying that you will still have to take your car in to get it fixed. If you own one of these cars, keep an eye out for a notification letter from BMW, which is due to be sent out on March 17th.