So you are NOT having the same issue as the OP, got it.
You wouldn't happen to have any dashcam video of your YOUR issue would you?
-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Cruise control inappropriately slamming on brakes
- Thread starter mckince
- Start date
You wouldn't happen to have any dashcam video of your YOUR issue would you?
CheezyNachos
Member
I'm also not sure if this has anything to do with it. The car lets you know when there is an emergency braking event. The same does not happen to me during phantom braking.
THOSE two events may not be related, but if you turn off Automatic Emergency Braking, then you have turned off a safety feature.
Personally, I will suffer through some phantom braking incidents to keep a safety feature on.
CheezyNachos
Member
Right. What I was implying is that I would not turn it off either, because it does not appear that one would have anything to do with the other outside of the poster's personal anecdote.
I think the point they were making was that if AEB is activated, the car is going to alert as such. Phantom braking events are(*generally*) seemingly acute slowdowns with no alerts whatsoever. I will concede that it is possible for phantom braking events that alert and maybe even trigger AEB but that is not what is generally described when people complain about phantom braking.
Knightshade
Well-Known Member
Part of the problem is the lack of definition. Some folks use the term for when the car slows down 5 mph in the right lane approaching on/off ramps or cresting a blind hill.
Some use it for when a map error causes the car to think it's in a 45 zone now when they were doing 70 (which happens much less often than the first case)
Also, perception. When the car does something you didn't command and didn't expect, it SEEMS far worse than it objectively is.
A while back someone actually measured "phantom" braking with an accelerometer and it was like 0.2g, which isn't nearly as hard as some folks perceive it, but when you don't expect it it seems like OMG SOMEONE WILL SLAM INTO ME.
Some use it for when a map error causes the car to think it's in a 45 zone now when they were doing 70 (which happens much less often than the first case)
Also, perception. When the car does something you didn't command and didn't expect, it SEEMS far worse than it objectively is.
A while back someone actually measured "phantom" braking with an accelerometer and it was like 0.2g, which isn't nearly as hard as some folks perceive it, but when you don't expect it it seems like OMG SOMEONE WILL SLAM INTO ME.
Absolutely. Lots of different perceptions of what phantom braking is, and it has evolved over time because of additional features being added and additional things being tracked by the car. When the Model 3 was new 2017/18, you only had TACC and lane keeping. There was no NoA and the car could care less about whether there was an onramp/offramp or lane merge because it wasn't tracking it then. At that time, phantom braking was pretty much caused by an overpass/shadow that confused the vehicle only. Oncoming cars caused things too but I didn't consider that phantom braking.
This phantom braking should not affect your safety score like it does. My experience shows it brakes and emergency warnings when tree shadows appear on the road, you easily can go around a bicycle, coming over a knoll and a bird is on the road, etc. When this happens and it screams at you, I startle and sometimes add to the brakes. There goes your safety score for the day, down. The only problems I have had with my safety score is when I have the cruise ON. This shouldn’t be. Now my score is only 98.
Phantom breaking is going to kill me one day. Cruise control at 80mph on a two lane high way was easy in my Subaru. In my 2021 Y, hard mode. Even when the road is empty it’ll still brake check me. Today, driving past a semi it braked hard down to 70mph before I slammed on the gas pedal. some how I didn’t get rear ended.
Other than another driver over-reacting with road rage, no one is going to die from a car unexpectedly braking. I am certainly not defending phantom braking (though it has decreased quite a bit), but this over-reactive hyperbole needs to die.
Where do you get the idea that sudden braking can't result in a deadly crash? You can type four words into Google and have a plethora of articles providing evidence to the contrary
Not only for the driver in the braking vehicle, but occupants of vehicles behind the braking vehicle
Last edited by a moderator:
I had a phantom braking event in my July '21 build, Vision 3 SR+ (2 lane highway, at night, only cruise control active, not AP) where I was cruising around 75 mph and then all of a sudden the car slammed on the brakes so hard my son's head actually bounced off the driver's seat slightly. I won't use AP (or even CC) with the family in the car anymore, and will only use them (very alertly) if I'm alone.
Knightshade
Well-Known Member
Folks have been saying OMG AP BRAKING IS GONNA KILL SOMEONE SOON for years.
To my knowledge the # of actual accidents, let alone deaths, from this remains at 0.
That's not to say it's physically impossible or anything- but based on Teslas published data, driving on AP results in vastly lower accident rates than driving without it.
To my knowledge the # of actual accidents, let alone deaths, from this remains at 0.
That's not to say it's physically impossible or anything- but based on Teslas published data, driving on AP results in vastly lower accident rates than driving without it.
Can you, and every one else "we'regonnadie", be more precise about the rate of deceleration and the end speed when the deceleration is stopped?
In 2 years of driving a Model 3, I have experienced occasionally what I would call phantom braking, but I would never ever characterize it "slamming on the brakes". Anyone following me during such events would probably think that I missed an exit or something and never the situation would elevate beyond an occasional annoyance instead of an imminent life-threatening danger as characterized by some posters.
It happened so quickly I don't remember all the details, but it was hard enough to have everyone in the car lurch forward rather severely. As soon as I realized what was happening, I put the pedal down to speed back up to cruising speed. If someone were behind me within a couple of car lengths, very good chance they would have at least tapped the rear. I wouldn't say it was full on slamming the brakes, but I'd say at least 3/4 braking.
Quick Google search brings this up immediately
UPDATE: Was Tesla Phantom Braking The 'Cause' Of This Multi-Car Crash?
Cars with features like adaptive cruise control and automatic emergency braking can sometimes brake by mistake. Tesla vehicles aren't immune to this issue.
insideevs.com
Of course, the blame in a phantom braking incident would likely fall upon drivers following too closely whereas intentional brake-checking would be treated differently
SalisburySam
Active Member
Er, apparently not. There are many posts of even worse phantom braking on current v36 and v40 non-FSD beta versions, and I certainly experience this on v36.5.1. I have FSD but I‘m not in the beta testing so I cannot confirm with first-hand knowledge but the posts show even they continue to have phantom braking. Doesn’t seem to be going away anytime soon, assuming it even can. I would really like to think Tesla is aware and addressing this for real, but I see no evidence of that.
Similar threads
