NHTSA Opens Formal Investigation of 416,000 Tesla Vehicles for ‘Phantom Braking'

author: FutureCar Staff    

It seems like electric automaker Tesla can't catch a break in 2022. The company is already dealing with three seperate recalls this year, in addition to the ongoing scrutiny surrounding the performance of its Full Self-Driving (FSD) software.

Now Tesla's latest problem is the opening of a formal investigation by the National Highway Traffic Safety Administration (NHTSA) of roughly 416,000 vehicles after reports of unexpected braking events when drivers have the automaker's Autopilot automated driving system activated.

The NHTSA confirmed earlier this month it was reviewing consumer complaints that Tesla vehicles were activating the brakes unnecessarily. This preliminary evaluation is the first step in the process that could lead to formal recall if warranted.

The preliminary evaluation covers 2021-2022 Tesla Model 3 and Model Y vehicles in the United States after the agency received 354 complaints about the issue over the past nine months.  The vehicles under review are equipped with Tesla's Autopilot Level-2 automated highway driving feature.

The NHTSA said that "Complainants report that the rapid deceleration can occur without warning, at random, and often repeatedly in a single drive cycle."

Tesla owners have already made the company aware of the problem, which is also referred to as "phantom braking", where the vehicle applies the brakes for no apparent reason. However their complaints were largely dismissed by Tesla, which said it was normal.

In May 2021, Tesla Chief Executive Elon Musk said removing one of the radar sensors used by the Autopilot system would prevent the phantom braking events. 

Like safety systems from other automakers including Automatic Emergency Braking (AEB) features offered standard on many new vehicles, Tesla's Autopilot driver assist system can apply the vehicle's brakes if there is an unexpected object in the road or another vehicle ahead stops suddenly.

An owner of a 2021 Tesla Model Y reported to the NHTSA in Oct 2021 that the brakes suddenly applied while driving on a highway at 80 mph.

"The car braked hard and decelerated from 80 mph to 69 mph in less than a second," the owner said. "The braking was so violent, my head snapped forward and I almost lost control of the car."

Last summer, the NHTSA  opened an investigation for Tesla vehicles failing to stop for emergency vehicles. NHTSA in August opened a formal safety probe into Tesla's Autopilot system in 765,000 U.S. vehicles after a series of crashes involving Tesla models and emergency vehicles. One of the Tesla vehicles crashed into the back of a stopped fire truck that was responding to another incident.

Earlier this month, Tesla announced it was recalling its "Full Self-Driving" (FSD) software, which may cause the vehicle to not come to a complete stop at stop signs. The recall affects 54,000 vehicles with the beta version of the more advanced FSD autonomous driving feature.

The recall covers Model S sedans and X SUVs from 2016 through 2022, as well as 2017 to 2022 Model 3 sedans and 2020 through 2022 Model Y SUVs. 

Tesla said it will disable the feature with an over-the-air software update. 

The "rolling stop" feature was added in October so the vehicle behaves more like human drivers at stop signs, as drivers often don't come to a complete stop before proceeding through an intersection. The rolling-stop feature allows Tesla vehicles to go through intersections with all-way stop signs at speeds up to 5.6 miles per hour, which essentially treats them as yield signs instead.

Tesla beta testers were required to "opt-in" to use a setting dubbed "Assertive Mode", which prompted NHTSA to raise questions with Tesla.

Days later, Tesla recalled 2021-2022 Model S sedans and Model X SUVs, 2017-2022 Model 3, and 2020-2022 Model Y vehicles to address a malfunctioning seat belt chime. The problem is that the audible chime may not activate when the vehicle starts and the driver has not yet buckled their seat belt. 

A year ago, the NHTSA requested that Tesla recall roughly 135,000 vehicles due to premature failures of the center-mounter touchscreen display. The vehicles affected include Tesla's flagship Model S sedan and Model X SUV. The NHTSA announced in Nov 2020 that it was expanding its probe into nearly 159,000 Tesla Model S sedans over reports of the center touchscreen display failures.

The NHTSA made its request in a formal letter sent to Tesla on Jan 13, 2021. It gave Tesla the opportunity to voluntarily recall the vehicles on its own, a preliminary step before the auto safety agency issues a mandatory recall.

Tesla wrote in its filing with the NHTSA that "in the interest of bringing administrative closure to the investigation and to ensure the best ownership experience for our customers" and agreed to comply with the request.

In total, Tesla issued 10 recalls since October, many of which were for software issues. Tesla's software-based vehicles have allowed the automaker to fix many of the recalled vehicles with an OTA software update, which is much easier than owners having to take their vehicles in for service.

FutureCar Staff