Tesla cars ‘phantom braking' complaints at high speeds spur formal NHTSA probe

The National Highway Traffic Safety Administration is investigating complaints of Tesla cars with Autopilot driver assist that suddenly brake at high speeds, the latest in a string of confrontations between the company and safety regulators.  The agency said it is launching a preliminary investigation after receiving 354 complaints that “unexpected activation of braking system may cause rapid deceleration.” NHTSA previously confirmed it was reviewing complains about the phenomenon, which has been dubbed “phantom braking.” 

Driver complaints include an unidentified 2021 Tesla Model 3 driver in Madison, Wisconsin, who complained in January of his car braking unexpectedly at highway speed, according to a filing on the NHTSA website.

“I was driving north on Wisconsin route 14 at about 60 mph in my Tesla model 3 using the cruise control,” the driver said in the complaint. “When a large transportation truck came from the opposite direction, my Tesla suddenly braked sharply. A Ford F150 truck was following behind me and almost crashed into the back of my car.”

The probe adds to a slew of recalls and investigations of Tesla vehicles. Two weeks ago Tesla announced its 11th U.S. vehicle recall in roughly four months, the latest in a spurt of safety-related fixes that have coincided with regulators subjecting the carmaker to greater scrutiny.

In August, the agency opened a defect probe of Tesla’s advanced driver assistance system known as Autopilot after repeated collisions with police cars and fire trucks. Weeks later, the company beamed an over-the-air update to its vehicles that sought to improve how Autopilot handles crash scenes. NHTSA asked the carmaker in October to justify making the software change without filing a recall.

No crashes or injuries stemming from the latest braking issue have been reported. The complains involved cars outfitted with Autopilot, NHTSA said in a filing posted on website Thursday morning. 

“The complaints allege that while utilizing the ADAS features including adaptive cruise control, the vehicle unexpectedly applies its brakes while driving at highway speeds,” the agency said in the filing. “Complainants report that the rapid deceleration can occur without warning, at random, and often repeatedly in a single drive cycle.” 

Tesla shares extended their decline in early trading, falling as much as 1.5% to $909.49 as of 6:10 a.m. New York time.

Tesla, which has disbanded its media relations department, did not respond to a request for comment on the NHTSA investigation. 

The latest investigation covers an estimated 416,000 2021-2022 Tesla Model 3 & Y vehicles.