In November, we learned that the National Highway Traffic Safety Administration Open engineering analysis of a potential defect With the popular Tesla S and X electric cars. On Wednesday, the other shoe fell, when the NHTSA informed the US automaker that it had to recall 158,000 cars to fix defective touchscreens.

The problem relates to a component in vehicles’ infotainment systems, called the media control unit. Buried inside the MCU is an 8GB eMMC NAND flash memory stick, which can only be written a limited number of times. Once this number of read / write cycles is reached – something that takes three to four years depending on how much the vehicle is driven – the touchscreen dies off. Unfortunately, this is a real problem in a car where the touchscreen is the way nearly all controls are accessed.

Not being able to surf the internet in your car or broadcast a podcast is clearly an inconvenience, especially in a high-end car. But the NHTSA is more interested in the fact that should the touchscreen die, functions such as backup camera and window defogging, as well as audio alerts for other safety systems on board, are lost.

The problem is well known among the Tesla community, as it affected any Model S built between 2012 and 2018, and the Model Xs built between 2016 and 2018. After the NHTSA received 537 complaints from owners, Tesla asked if it had more information About the scope of a problem. It did – delivering records for thousands of complaints and over 12,000 MCU replacements.

Now, the NHTSA has taken unusual steps telling Tesla that it must recall 158,000 affected vehicles, According to Reuters. “[D]As we review the data, Tesla provided an assurance that all modules will inevitably fail due to the limited storage capacity of the memory device. ”The NHTSA also indicated that Tesla attempted to solve the problem with software patches, but these were“ procedural ”and largely insufficient“ and the law requires automakers Recall vehicles that have safety defects.

Tesla does not have a press office to contact for comment, and the company has not released any statement either on its Twitter feed or CEO Elon Musk’s summary. The company has since redesigned the MCU to use 64GB eMMC memory, so it shouldn’t be affected by modern vehicles. The more popular 3 and Y Models are not affected by this issue.