US Regulator Launches Probe Into Tesla ‘Phantom Braking’

The US government’s automobile safety regulator has begun a preliminary investigation into unexpected “phantom braking” by Tesla’s Autopilot driver-assistance system.

The National Highway Traffic Safety Administration (NHTSA) said it began the probe in response to 354 complaints it has received over the issue in the past nine months.

The complaints say that when Autopilot is engaged on motorways, it can at times unexpectedly slow the vehicle down when no obstacle is present.

The regulator said no crashes, injuries or fatalities have been caused by the incidents, but complaints alleged that the issue has led to near-misses.

Unexpected braking

In spite of the feature’s name, Tesla says Autopilot “does not make the vehicle autonomous”.

The NHTSA’s Office of Defects Investigation (ODI) said it has begun a “preliminary evaluation” of the issue, which could eventually lead to an official recall of affected vehicles.

The investigation covers about 416,000 Tesla Model 3 compact sedans and Model Y hatchbacks manufactured in 2021 and 2022 and sold in the US.

The complaints allege that while using Autopilot features, “the vehicle unexpectedly applies its brakes while driving at highway speeds”, The NHTSA said in a statement.

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

“ODI is opening this preliminary evaluation to determine the scope and severity of the potential problem and to fully assess the potential safety-related issues.”

Safety concerns

One of the complaints, made available by the agency on its website, said that the vehicle “arbitrarily applies the brakes when adaptive cruise is being used”, adding that it “is scary to me and my passengers, and I am afraid to use this feature”.

Many of the complaints note that unexpected braking occurs on two-lane highways when vehicles approach from the other lane or when there is a stopped car on the shoulder, but according to one complaint, “most incidents have been on open roads with no obvious hazards ahead”.

This complaint added that the issue had also occurred “at least three times” on motorways with multiple lanes.

Tesla is currently under investigation by the NHTSA for two other matters. One involves its Passenger Play feature, disabled by the company in December 2021, which allowed games to be played on the dashboard touchscreen while the vehicle was in motion. The investigation covers about 580,000 vehicles.

Autopilot questions

Last August the agency began a probe into the role of Autopilot in 11 crashes in which Tesla cars collided with emergency vehicles that had flashing lights turned on.

Separately, last year Tesla recalled 54,000 cars equipped with Full Self-Driving software to disable a feature that under certain conditions allowed the vehicle to roll slowly through intersections with stop signs, following meetings with the NHTSA.