When the Tesla Model S electric vehicle launched in 2012, one of its stand-out features was the enormous central touchscreen in the dashboard that replaced nearly all physical on-board controls. It quickly became a selling point of the car with a simple, elegant user interface, intuitive controls, and even hidden ‘easter eggs’. Although many rivals had used touchscreens for a long time, none were remotely as large as Tesla’s unit.

However, earlier in January, the US’s National Highway Traffic Safety Administration (NHTSA) finally issued a formal letter to Tesla, informing the automaker that it had determined the screens in 2018 and earlier Model S and Model X vehicles posed a safety risk. The risk was centred around the fact the driver would lose some critical safety functionality if the screen or the software driving it failed. In particular, they would no longer be able to operate the demister or the reversing camera, which could potentially lead to an accident. Anecdotal reports told of drivers suddenly unable to access most vehicle functions because their central screen had gone black and become unresponsive.

Sending a letter in this manner is rare because most OEMs opt to issue voluntary recalls for defective parts before having their hand forced by regulators. If Tesla continues to ignore requests to issue a recall, it could lead to legal action being taken against the automaker, which could force it to replace screens en masse, along with doing damage to the automaker’s reputation. The NHTSA said it has gathered more than 12,000 complaints and warranty claims related to Tesla’s touchscreen.

Now, to worsen Tesla’s headache, the Kraftfahrt-Bundesamt (KBA) transport authority in Germany has confirmed that it is investigating possible safety risks posed by Tesla Model S and Model X touchscreens. Tesla has not yet commented on either the US or German investigations but it will likely have little choice to respond if it leads to the threat of legal action.

Automotive grade versus industrial grade

There have been question marks over how appropriate Tesla’s screens were for their intended application for some time. One particularly prominent problem is known as ‘yellow banding’. This issue sees a prominent yellow border develop around the edge of the screen over time. Many commentators noted that this issue was similar to problems observed in a number of consumer electronic devices, typically caused by the screen getting too hot. Tesla began replacing screens free of charge up to the end of 2018 but, since then, has only offered a free ultraviolet ‘healing’ service – it is unclear how successful this fix is, with some owners reporting the screen returning to normal, while others have said the problem remains after the remedy. Some owners in the US have successfully entered arbitration against the automaker to force them to fix the problem.

Tesla opted to fit industrial-grade touchscreens that were more commonly used in industrial and medical applications.

So why are screens in Teslas failing under high heat? As revealed in Ashlee Vance’s biography of Elon Musk, the tech entrepreneur wanted a large central screen in the Model S but nothing like it existed in the automotive supplier space at the time. As a result, Tesla opted to fit industrial-grade touchscreens that were more commonly used in industrial and medical applications. The critical difference here is that thermal and vibrational testing for industrial-grade components is less intense than the testing carried out for automotive-grade units.

In the biography, it is stated that Tesla carried out its own internal tests that showed the industrial-grade screens met its criteria, but years of real-world testing by owners shows that this was insufficient in practice. Dashboards receive an outsized share of the thermal load experienced by the car thanks to being centralized in the cabin, often directly under a sunroof, potentially for hours at a time and, in the case of the Model S, also have HVAC and on-board electronics systems hidden behind them, adding even more heat to the mix. Again, this added weight to the assertion that screens in early Model S and Model X cars were not fit for purpose because they didn’t meet automotive levels of robustness, but were tasked with many critical on-board functions in place of physical controls and switches.

It seems, in its haste to beat rivals to the mark by releasing a car with an enormous central touchscreen, Tesla might have overlooked some of the critical reasons why such a large screen had not yet been invented for automotive-specific applications. If the screens are determined to be too great a safety risk, Tesla might be forced to issue a recall in certain markets. In addition, it will suffer reputational damage because it will be seen to be dragging its feet on a safety-critical issue.

This article first appeared on GlobalData’s research platform, the Automotive Intelligence Center