Tesla will recall nearly 135,000 older models for issues related to its touchscreens, primarily Model S sedans. Getty

Tesla has been getting mostly good news lately, which contributes to a stratospherically high stock price. But the automaker suffered a setback Tuesday with the announcement of a 134,951-vehicle recall for Model S and Model X cars because of faulty touchscreen display circuitry that could create safety issues.

After an investigation, the National Highway Traffic Safety Administration (NHTSA) requested the recall in a January 13 letter to Tesla, which then agreed on January 27 to voluntarily carry it out. The notice was posted Tuesday by NHTSA. In the recall, Tesla will replace the failure-prone parts and repay owners who previously had to shell out cash to update them.

How to Tell If There’s a Problem

The problem relates to 2012 to 2018 Model S cars and 2016 to 2018 Model X SUVs equipped with infotainment system media control units (MCUs) that use the Nvidia Tegra 3 processor and an integrated eMMC NAND eight-gigabyte flash memory device.

Translation: The media control unit links the center display to functions such as climate control, backup cameras and infotainment. eMMC means an embedded MultiMedia (memory) Card typically soldered to a circuit board (as Tesla did) rather than plugged into a socket.

Flash memory is the type that retains its contents when the power is off (USB sticks and camera storage cards use this technology). NAND refers to the internal architecture of some flash memory. This type of memory has a finite number of times new information can be written onto a device. Reading data from the memory does not impact longevity.

Tesla S Screens
A customer browses through the screens on a Tesla Model S in 2015. PATRICIA DE MELO MOREIRA/AFP via Getty Images

According to Tesla, affected cars may display a memory-degradation message later followed by a screen that goes blank and can’t be reset.

As part of the recall repair, Tesla will replace the 8-gigabyte memory module with a 64-gigabyte chip and software will load-level or move around the locations where data is stored, so the new chip will store more information and/or last about eight times as long. Because of parts shortages, Tesla is asking owners not to bring their cars in for service if the displays still work.

Flash Memory Will ‘Inevitably Fail’

The flash memory is accessed every time the vehicles are started, NHTSA said, adding that Tesla provided confirmation during  the investigation that the units “will inevitably fail, given the memory device’s finite storage capacity.” If the flash device stops working, the car’s 17-inch center display screen can fail and go blank.

Losing the ability to play music off a smartphone or access onscreen garage opener buttons isn’t a safety issue. But this is: the loss of the rearview/backup camera (a federal mandate) and HVAC defrosting and defogging, NHTSA said. Other possible effects are to the Autopilot self-driving system, turn signal functionality (the loss of audible chimes), and related driver alerts.

Tesla Model S Factory
The recall affects Model S sedans build from 2012 to 2018 and Model X SUVs built from 2016 to 2018. Like all vehicles, as they age systems can degrade and in particular, flash memory can be used to its capacity, which may prompt recalls in other vehicles with similar technologies. Getty

NHTSA’s investigation showed MCU failure rates of between 14.2% and 17.3% in 2012 to 2015 Model S vehicles, and between 1.9% and 4.1% in 2016 to 2018 Model S sedans and X SUVs. The agency said that it believes “failure rates will continue to accelerate, as shown in Tesla’s projection models.”

NHTSA is on safe grounds there: The more a Tesla is driven, and the more memory is changed with updated settings, the greater the odds of failure. NAND is not a forever type of storage if new information is constantly written to the memory.

The agency said in its message to Tesla, “NHTSA notes that Tesla has implemented several over-the-air updates in an attempt to mitigate some of the issues described in this letter, but tentatively believes these updates are procedurally and substantively insufficient.”

Display Bricks? Tesla: “Use the Mirrors When Backing”

In a response to the government request dated January 29, Tesla agreed to the recall “in the interest of bringing administrative closure to the investigation and to ensure the best ownership experience for our customers.”

The company said that it was unaware of any crashes, injuries or deaths arising from the situation, and opined, “For vehicles for which these functions are not available, drivers can continue to operate the vehicle by performing a shoulder check and using their mirrors when backing, taking care when making turns, and assuring clear visibility when driving.” It also said that drivers unable to access the defroster will be able to “manually clear the windshield,” that is, wipe it with a rag.

2021 Tesla model S
The Model S is Tesla’s flagship, and many early buyers were early adopters of all kinds of new technology. As in many advanced cars, electric or otherwise, today’s hot new tech can also be tomorrow’s hardware issue. Tesla

Tesla says owners who upgraded to recent software (over the air, using Tesla’s onboard cellular data modem), will have a limp-home mode which maintains the backup camera onscreen display, enables a pre-set cabin temperature with windshield defogging, and keep the turn signals active. It won’t bring the failure memory module back to life, however.

Tesla hasn’t always responded quickly to recalls, safety experts say. William Wallace, manager of safety policy for Consumer Reports, tells Forbes Wheels, “This is clearly a safety issue and we’re glad people’s cars will get repaired. It probably would’ve happened much faster if Tesla hadn’t dragged its feet. Tesla has a long history of resisting necessary recalls, despite the company’s obligations to the public and our safety laws. NHTSA should hold Tesla accountable for its delays.”

“Everything Tesla Does Is Under Inense Scrutiny”

According to Jessica Caldwell, executive director, Insights, at Edmunds, Tesla needs to be proactive as moves beyond a fairly small market niche. “Automotive recalls are nothing new in this industry,” she said, “but considering Tesla is the world’s most valued car company, everything they do is under intense scrutiny.

“This recall is on one of their hallmark products—their touch screen—which is something tangible to a consumer. And now that Tesla has rolled out mass-market products to consumers who may not be as tech savvy as their early adopters, Tesla will have to put increased efforts in the realm of customer service so these consumers come back to the brand—just like every other car company has been doing for decades.”

“Tesla Going to Drag This Out”

The recall could be protracted, said Sam Abuelsamid, principal analyst for e-mobility at Guidehouse Insights. “The parts in the original Tesla MCU are not used anymore, and they are apparently in short supply,” he said.

“Rather than just replace all of them now with new components that they charge $1,500 for, Tesla plans to do a phased recall, starting with the cars that have the most cycles on them first,” Abuelsamid tells Forbes Wheels. “I suspect that Tesla is going to drag this out, hoping that some number of these vehicles are retired before the MCU fails.”

2021 Tesla Model Y
While the recall back-and-forth between NHTSA and Tesla was playing out, the agency officially gave the Tesla Model Y a five-star overall safety rating. Tesla

Backup cameras are, of course, now required safety equipment on all new U.S. cars. NHTSA has recalled many other cars for the failure of these cameras, including models from Mercedes-Benz, BMW, Nissan, Bentley, Jaguar Land Rover, Honda, Subaru and Maserati.

NHTSA is always watching, and on January 13, Tesla’s Model Y SUV got a five-star overall safety rating from the agency.