Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Phantom braking events with pics

This site may earn commission on affiliate links.
Just took a trip from Orange County to Las Vegas. On the return trip we experienced 3 phantom braking events while in autopilot mode. Each event had one thing in common --- a "dark" object perpendicular to the road surface. See the pics and let's hear if you've encountered something similar. As others can attest.. it scares the hell out of you when you're doing 75 and the car hits the brakes without warning.
phantom1.jpg
phantom2.jpg
phantom3.jpg
 
I did 800 miles yesterday and had probably 10 hard brakes with nothing around, not even shadows or tar snakes as far as I could tell. Not a single braking with cars coming at me on a 2 lane road, that was a huge fix, but this seems to have gotten worse.
 
What month/year was your car built? I'm on 12.3.2, 9/2021 build date, and AP handles those exact situations really well. All previous versions would freak out and slow at least 5, sometimes up to 15 mph, not every shadow, but at least half of them.

12.3.2 and 12.3.3 should be about the same, only bug fixes, but who knows. I've heard others on 12.3.2 still have bad PB.

Really weird how the same software can behave so differently in different individual cars. Makes figuring out any solutions in a general way almost impossible.
 
Double-check the screen's posted speed limit at the time of the braking event. I know along my daily route which just happens to be North America's busiest highway, there are map data errors either about speed limits or for whatever reason my position where it thinks I am in an off-ramp. Entirely map data related, and not vision related.
 
I had an event on a local, high-speed (75mph) toll-road the other day. While crossing under the toll-reading gantry the car on FSD with speed set at 80mph, the car braked really hard!! I went from 80 to about 45 in a heartbeat, it took me a second to get onto the accelerator and stop the braking action. We have a lot of accidents and fatalities on that road, averaging at least one a year, and I was so damn happy no one was behind me. Praying Tesla sends a fix soon!!
 
No pic but had my first "real" phantom breaking that made zero sense. In the past there was always "something" that I was like "ah that makes sense" that the car wanted to "react". Overpass, truck near by, construction barrel, road lanes shifting...

This time nothing around but it was a two lane road....if I wasn't prepared to take over and accelerate I think I'd have flat spots on my tires...but it never got the change.

I will only use Auto Pilot from now on on the highway...just not worth the effort at least for now.
 
  • Like
Reactions: DWtsn
Sorry no pics. The phantom braking was keeping me busy. I went on a 3,200 mile trip 2 days after taking delivery. 10 / 800 doesn't sound bad. I had more like 10 episodes per mile. Mostly heat mirages that look like water, cloud passing overhead casts shadow that runs across highway, skid marks on highway, shadow below overpass, shadow from trees, and most of the rest unknown. ONE was really well done. 10PM on a dark night, way out in the country, on a narrow dirt not gravel road. Popped over a little hill driving around 30mph, it slapped on the breaks to a full stop! Nobody within 10 miles, so tried to figure out why. After maybe 15 seconds, I could see there was a deer about 20 feet off the road standing well hidden in bushes. I just sat and waited. After another 20 seconds or so, the deer slowly walked out of the brush onto the road and straight up to the front of the car. Looked at it a bit, turned around and started walking down the middle of the road. At a respectful distance of 50 feet or so, the car started up and followed the deer. Another 100 feet down the road the deer veered off the road and walked off into the bushes. Car went back up to 30 mph and continued on. No complaints here! Good Job 42.
 
  • Like
Reactions: DWtsn
I've seen about three different instances of phantom breaking. First is encountered as a result of signs positioning; often experienced at you come over the crest of a hill and the sensor picked up a road sign across the roadway. The second is encountered with certain signs across the roadway with the shadow. The third is encountered with differences with the roadway surface that span the highway in the shape of a rectangle. The interesting part of this, is that it isn't consistent which I believe might be due to the angle of the sun.
 
Got to see my first one today. Driving home around 7pm in the middle of 3 lanes going 60. Little to no traffic.
Blue model 3 was coming up about 65mph on the inside lane. Just as it was getting past me... whoosh, gone, slammed on the brakes.
No traffic, straight roadway, no overpass. There were some shadows on the road from the sun setting behind the trees.
 
Don’t plan to use autopilot on my new m3 - I m not sure why owners put up with multiple close calls of slamming on brakes by surprise - I don’t want it even once - kind of a shame because we pay for it to be included in base price - I would opt out for now It Tesla made autopilot optional - ag
 
With a 2020 Model Y, I had no issues. This 2021 Model Y has the PB problem. Never know when but relax and then it hits me. Tesla owners are a forgiving bunch. We generally love our cars. Nevertheless, we should not have to accept a "feature" that works better on most other brands. I imagine radar ranging is far more accurate than optical but it doesn't matter what I think. It matters that in this respect, my Tesla is substandard.
 
  • Like
Reactions: DWtsn and alangold
With a 2020 Model Y, I had no issues. This 2021 Model Y has the PB problem. Never know when but relax and then it hits me. Tesla owners are a forgiving bunch. We generally love our cars. Nevertheless, we should not have to accept a "feature" that works better on most other brands. I imagine radar ranging is far more accurate than optical but it doesn't matter what I think. It matters that in this respect, my Tesla is substandard.
Been on a few road trips recently, and I think about hands off the wheel and what that might be like... I really enjoy having adaptive cruise control where all I have to do is steer. I think I would be more stressed watching the car do its thing and constantly wondering when I need to jump in.
 
  • Like
Reactions: alangold
I just drove to Phoenix and had 2 PB events within 30 minutes of each other - on completely open, empty highway east of Indio...
I dont want to use the Autopilot as its clearly dangerous - imagine if a big-rig was behind me. It lowers the value of the autopilot and the car if you cant use it for its intended use. My wife was freaked out by the deceleration it was so jarring. And I love my Tesla too!