SACRAMENTO, Calif. — Tesla helped launch the electric vehicle industry and is pushing the limits of autopilot technology, but a hidden flaw could be a danger to some drivers.
Tesla’s automatic emergency braking “detects cars or obstacles that the car may impact and applies the brakes accordingly,” according to the company’s website. It's a feature in Tesla's autopilot system, which comes included in every Tesla sold after early 2019 and was an add-on prior to that. It’s also a feature in any Tesla with enhanced autopilot and full self-driving or “FSD” systems.
Automatic emergency braking — engaged when a driver has turned on the autopilot setting — can avoid collisions and even save lives.
Sometimes, however, the car’s sensors think something is in front of it and the car slams on the brakes even though nothing is there.
It’s a phenomenon called “phantom braking,” and it's led to at least one death in recent years, according to the National Highway Traffic Safety Administration. A Tesla on a Missouri freeway unexpectedly slowed to a near-stop and the driver got rear-ended and died as a result. Others involved in the crash survived.
Phantom braking has been documented in videos shared by Tesla owners. Their vehicles suddenly slam the brakes, often on open roadways, quickly slowing in response to imagined hazards.
An investigation by ABC10’s sister station reviewed thousands of federal auto safety complaints. It found phantom braking is more widespread than previously reported and many drivers aren’t aware of the risk because Tesla, along with federal auto safety regulators, haven’t done much to warn them.
"I could have been killed. It was terrifying,” said Tesla driver Kathy Kopacek.
Kopacek was on a road trip this summer when her 2022 Tesla Model Y suddenly slammed its brakes while in cruise control along an open stretch of interstate.
“I thought, oh my gosh. What happened?" she said.
She was shaken but thought it was a fluke until the same thing happened a few hours later. Again, at highway speeds.
“I mean, I was 70, 72 mph and it stopped fast," she said. “Everybody around me was swerving, screeching."
Phantom braking is the glitch in the system. Automatic emergency braking, however, can lead to safer driving, Tesla owners tell ABC10.
“I'd have to say it's probably a better driver than I am,” said Tesla driver Ken Spencer, of Lincoln. “Saved me from a rear-end on Business 80 down over by Haggin Oaks. Admittedly, I was distracted; I was looking at something over here. Car in front of me slammed on its brakes. The car went, ‘beep, beep, beep, beep’ and stopped. It wasn't a huge speed difference but it would have crunched up a couple cars.”
Spencer has owned and driven Teslas for the better part of a decade and has experienced phantom braking.
“It happens, but I drive with my foot near the brake,” he said. “It's a bit of a shock, but the fact that it's such a shock to these people should say that it doesn't happen very often, but be ready, I think, is the thing.”
A driver can immediately override phantom braking by pressing the brake or accelerator. It’s a matter of paying attention, Spencer says.
“You have to be vigilant; you're driving a 4,000-pound missile at, you know, 60, 70 mph,” he said. “It's easy to get complacent, but you shouldn’t.”
Tesla driver Jack Brown, of Santa Cruz County, agrees.
“I have been using autopilot for the last five years in the car. I’ve been generally pretty happy with it but realize it's beta software and there are waivers saying you’ve got to keep your attention on the road,” Brown told ABC10.
He says phantom braking has happened to him about a half-dozen times in five years.
“The thing I've noticed is if I get along, like, a white semi-truck, for some reason it wants to do it. And if it's a very bright day and I'm going through an overpass and the shadow being cast from that it's like, ‘Okay, that's probably why it happened,’” he said. “(I was) ready, you know. Disengaged by tapping the brake pedal and taking control of the car.”
A caution on Tesla’s website says, "Ensure all cameras and sensors (if equipped) are clean before each drive. Dirty cameras and sensors, as well as environmental conditions such as rain and faded lane markings, can affect Autopilot performance.”
The company emphasizes the technology is “intended for use with a fully attentive driver, who has their hands on the wheel and is prepared to take over at any moment.”
ABC10 spoke with dozens of other Northern California Tesla owners. Some said they rarely or never encounter phantom braking and questioned why we were doing this story.
But others shared stories of near collisions.
One driver told ABC10 “on a beautiful day, clear road it was slamming on the brakes as hard as possible from 80 mph. Scared us silly and everything from the back came flying up over the seats. If there had been traffic behind us we would have been toast.”
It happened several more times during that ride to the point where she now doesn’t use autopilot at all. She says she’d like to see Tesla offer a simple cruise control option following a set speed without using artificial intelligence.
Others say the issue has gotten better with software updates to their car and point out all the times the technology has helped them.
“The autonomous driving is something that's very new to everyone,” Brown said. “In the long term, at least, I think it's going to save a lot of lives more than it's going to hurt people.”
Days after that interview, Brown said he’d just completed a long road trip.
“120 miles into my trip from Santa Cruz to Carlsbad on 101 between San Ardo and Paso Robles on (Full Self Driving) and the car suddenly sets the max speed from 75 to 15 while in the left lane approaching a street underground with a pickup truck (bearing) down on me,” Brown said. “I disengaged and took over and moved to the right lane.”
ABC10 is hearing from drivers this phantom braking problem while in autopilot isn’t specific to Tesla and other automakers’ vehicles equipped with autopilot technology have experienced the issue, too.
See the full investigation HERE.
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