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phantom braking. Are you still experiencing it with latest software update?

Are you still experiencing it with latest software update

  • yes

    Votes: 88 72.1%
  • no

    Votes: 34 27.9%

  • Total voters
    122

ETinKC

Member
Mar 9, 2021
8
6
Kansas City. MO USA
Just took my first long trip, 1,500 miles in two days and it happened twice. Freaked me the **** out. Wasn’t paying enough attention to notice if there was an overhead sign or anything else that may have triggered it.
 

Gesteur

Member
Jan 24, 2018
39
17
europe
I have a Model S for 3 years now. I am based in Switzerland. I don't go on many long trips but I have just been on a 1000km round trip on motorways / Autoroutes and I had at least 2 scary phantom breaking experiences on the trip. I say scary as I was not expecting them and I can see that they can be dangerous when not expected. My 2 examples are linked to when entering a tunnel or passing under a bridge with Shadow on the road and with a vehicle or lorry on my right side. Now that I read that it is an experience that others have had I can understand why some Tesla drivers would be reluctant to use the cruise control function. I will still use it I think but with more caution. If I understand correctly this does not happen in other branded cars cruise control as they use a different basis to manage the cruise control ? Can someone advise on that ? My friend who was with me is an Audi driver and was quite shocked by the Model S Cruise Control behaviour.
Is Tesla cruise control a GPS based system as opposed to what else for other Car brands ? Thanks for any replies
I can only confirm that the phantom braking had gotten worse. I m also living in europe and get it on each travel i do on a highway, not on same spots.
The braking freaks the people in the car out, because it s unexpected.

Like this TACC is useless and Tesla should actually refund owners who paid for this useless *sugar*, ok autopark works, but imo TACC which is supposed to be a basic tempomat doesn't really work.

Of course Tesla will shift responsibility to the owner, but we are talking about functionality we paid and we cant use because it s buggy.
I remember that 2y ago it wasn't so bad, I dont think it will get better unless Tesla properly addresses this.
 

tij664

Member
May 8, 2017
391
534
Turlock, CA
I don’t think they will ever solve this. My wife’s first new vehicle ever was a 2011 Ford Edge which came with all the bells and whistles including TACC. That had some pretty scary phantom braking incidents on the freeway on a regular basis. It’s 2021 and if the supposed most advanced cars out there today (Tesla) are still doing it on a regular basis then it’s never going to go away.
 

S4WRXTTCS

Well-Known Member
May 3, 2015
5,631
6,406
Snohomish, WA
I don’t think they will ever solve this. My wife’s first new vehicle ever was a 2011 Ford Edge which came with all the bells and whistles including TACC. That had some pretty scary phantom braking incidents on the freeway on a regular basis. It’s 2021 and if the supposed most advanced cars out there today (Tesla) are still doing it on a regular basis then it’s never going to go away.
I agree that that this will never get solved ENTIRELY.

But, the two cases you're presenting are some of the worst offenders in the history of Adaptive cruise control systems.

In 2011 adaptive cruise control systems had some pretty major phantom braking issues especially in corners where nearby cars would confuse it, and would cause it to slow down. In fact I had a Range Rover Sport that didn't have ACC because the dealer claimed they were garbage, and refused to add it to any of their builds.

In 2015 I got my first Adaptive cruise control vehicle and that was a Tesla Model S with AP1. The system used Radar plus a single camera, and absolutely did not have any phantom braking issues at all. Over the years Tesla added various SW features to it that did introduce occasional phantom braking, but nothing all that worrisome.

In 2018 I traded it in on a 2018 Model 3, and the adaptive cruise control system was noticeably worse. There were periods where it seemed to improve with less phantom braking, and then periods where it seemed worse. In recent drives all my phantom braking events have been maps based. Maybe a handful of overreactions which I don't really count as phantom braking. Heck even some people will call some of my braking phantom braking like just today I braked because someone was getting way too close to my lane, and I just had a feeling. So I slowed down to see what he was going to do, and then gunned past him when he corrected his lane positioning.

Ultimately I think most of Tesla phantom braking issues are correctable. Either in allowing users more granularity in what to brake for or fixing the root causes of the phantom braking.

The stuff we can turn off while still having TACC:
  • Traffic light response -> Can sometimes phantom brake if it gets confused by a light/sign
  • NoA with unconfirmed lane changes -> can sometimes phantom brake if it thinks it needs to make a lane change
  • AP -> Can phantom brake if it suddenly thinks its on a different road type
The stuff we can't turn off:
  • Braking for vehicles that cars think will come over the line -> I've seen this cause phantom braking with large vehicles that the Tesla camera can't locate correctly so it thinks they're coming over the line.
  • Braking for corners -> Sometimes will cause phantom braking if the maps says there is a corner, and there is no corner.
If you looked at the available adaptive cruise control systems in the market you'll see a lot of them that don't have a phantom braking issue. Like I've never experienced a single phantom braking event with my Jeep Wrangler Unlimited, and its adaptive cruise control system. It's a very basic bare bones adaptive cruise control system that just works. I call it the "keep your foot near the brake" ACC as its more likely going to need my corrective action to brake. Where the Tesla ACC system is more likely going to be my corrective action to tell it to go. Heck these days my biggest issue with AP/TACC is phantom not going.

My brother has a Subaru, and a Honda with adaptive cruise control and neither of them have phantom braking issues either. The Subaru eyesight system mostly got its phantom braking issues sorted out in early generations. The early ones would get fooled by shadows of vehicles.
 
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TerryMcC

New Member
Jul 21, 2021
2
1
sydney
Hi,

I am fairly new to the Tesla world and have not yet experienced phantom braking but have wondered if there might be three separate things happening that are all being put in the one bucket and confusing things.

There seems to be descriptions ranging from 'slowing' to full on slam brakes.

In my understanding there are three systems (I don't have FSD so maybe even more) that might cause these events:

a) TACC: something here is causing various levels of braking.

b)Auto pilot: looses track of the road/lane and slows in confusion.

c) Autonomous emergency braking: Anyone had this activate when not in Autopilot/TACC? Anyone run with this turned off and still get problem?

Just some thoughts.
Tery
 
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Knightshade

Well-Known Member
Jul 31, 2017
12,814
19,002
NC
Hi,

I am fairly new to the Tesla world and have not yet experienced phantom braking but have wondered if there might be three separate things happening that are all being put in the one bucket and confusing things.

There seems to be descriptions ranging from 'slowing' to full on slam brakes.

In my understanding there are three systems (I don't have FSD so maybe even more) that might cause these events:

a) TACC: something here is causing various levels of braking.

b)Auto pilot: looses track of the road/lane and slows in confusion.

c) Autonomous emergency braking: Anyone had this activate when not in Autopilot/TACC? Anyone run with this turned off and still get problem?

Just some thoughts.
Tery



AEB does not require AP or TACC to be activated-- I had it happen once driving entirely manually crossing an intersection where I was going straight and someone shot out to turn in front of me when he didn't have right of way for example.

That said- someone did testing a while back and found changing the early/normal/late setting on emergency braking DID impact how often they got phantom braking, with "early" causing a LOT more of it. This was like 2 years ago now, so it's possible this isn't impactful today, I dunno, I've always had mine set to late and almost never (like can count on one hand with fingers left over in 20,000+ miles on AP) had "phantom" braking.
 
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TexasTezla

Member
Feb 28, 2020
221
187
Texas
I've had it a couple of times going in an underpass on the 35 in Texas (one was a slowdown the other a hard brake) but apart from that nothing else after 18 months of ownership. I recently drove from Santa Fe, NM to Dallas, TX with no issues at all. Pretty much AP all the way.
 

greymatter73

Member
Jun 7, 2021
170
214
Elk Grove, California
Was driving about 70mph on the freeway on Sunday with no cars around me with cruise control on when all of a sudden the car slammed on the brakes to the point you could hear the tires squealing on the pavement... while I was able to recover, I'm not sure if my wife will ever let me use cruise control or autopilot ever again with her in the car!
 

Knightshade

Well-Known Member
Jul 31, 2017
12,814
19,002
NC
I've had it a couple of times going in an underpass on the 35 in Texas (one was a slowdown the other a hard brake) but apart from that nothing else after 18 months of ownership. I recently drove from Santa Fe, NM to Dallas, TX with no issues at all. Pretty much AP all the way.


The overpass thing is the exact situation Tesla is removing radar to try and solve (there's a video from Karpathy explaining it if you're interested)
 

Phyzi Driver

Member
Jun 2, 2021
90
105
Houston, TX
Was driving about 70mph on the freeway on Sunday with no cars around me with cruise control on when all of a sudden the car slammed on the brakes to the point you could hear the tires squealing on the pavement... while I was able to recover, I'm not sure if my wife will ever let me use cruise control or autopilot ever again with her in the car!
It's pretty disheartening that Tesla continues to have this issue after so many years.
 

mrmtb

Member
Jun 18, 2021
9
13
Norcal
Had my first phantom brake while using AP today. 2021 SR+ 1k miles.

It was a slightly curvy section of the freeway that was well marked. No cars around me except for a big rig braking 4-500 feet in front of me in another lane. Too far for it to show up on the display and it's never applied brakes from that far away for any other car braking in front of me.

Luckily it wasn't too hard and it brought me down ~15 mph.
 
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Ecoli

Member
Aug 6, 2019
560
181
New Zealand
updated to 2021.12.25.6
Went for a drive today on a stretch of motorway I regularly drive
which I quite often engage AP/NoA without any phantom breaking

Today 2 occurrences of PB both looked to be the same scenario
Passing a car which was on my left, in the left lane
No bridges or overhead signs in front. in both instances the car I was passing was behaving normally
not drifting across the lane not signaling. I was traveling on the right in the right hand lane
My car suddenly decided to rapidly slow down and stop passing the car on my left
for no reason that I could see. It did this twice once on the way out and again on the return journey
I think it went from 100km/hr to about 70 or so. I did accelerate once I was sure nothing was wrong
I wasn't game enough for science to let the car decide how much it was going to slow down

With AP/NoA engaged I also passed other cars the same way and had other cars pass me
on the same journey without incident

May be its not phantom breaking, maybe it's driver alertness test to make sure your really are paying attention
to keep you on your toes, alert and ready for the unexpected...lol
 
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Fernand

Active Member
Mar 22, 2019
1,560
1,566
Northern california
I never had phantom braking. Maybe 3-4 in 2.5 years. But let's distinguish braking from slowing. Of late in NOA my car has been taking speed limit signs and slowing for curves more seriously, and that has apparently caused some unwanted slow-downs. On the other hand the overall performance in major curves and lane changes is better, much more human. It's still a horse you have to ride, don't let it gallop out of control.

There's a specific issue with lane widening, as when a right lane disappears. The car will always tend to center, so if there's a car coming up on the right it's a tricky thing. Either the car can still make it and continues, or it decides it's letting the other car through and slows down, sometimes a lot. I don't know what else they can do. Unquestioningly hugging the left would be dangerous.
 
Last edited:
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Fernand

Active Member
Mar 22, 2019
1,560
1,566
Northern california
Going from 2021.4.21 to 2021.12.25.6 I've had more significant slowdowns in freeway NOA mode in responding to conditions. For instance way earlier and excessive slowdown in approaching an exit.

It's not "phantom" or illogical, but wow. I suspect they are working on pure vision, getting rid of the radar dependencies (still not sure why). But I sure DO wish they would keep us somewhat informed, because at first glance, it might be tempting to imagine they just randomly make things a little better or worse for the hell of it. ;)

I confess I miss the way NOA worked a few months ago. It wasn't as sophisticated, it was pokier in changing lanes, but it was more predictable.
 
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Occhis

Member
May 26, 2019
237
106
Front Royal, VA
Most of my experience with PB is more than just slowing. When I’m in heavy traffic and the car “slows” from 65 to 45 unexpectedly for no apparent reason and quickly enough that it creates a possible rear end collision situation, I call that phantom. No to mention unnerving. So many tailgaters out there. Even when I’m expecting it b/c it’s in the same location as it’s happened before, it still startles me. The rate of deceleration is more than just slowing, definitely is braking. Now I just flip TAAC off just before I get to those 2 spots. With the exception of those 2 locations which BTW are in construction zones, PB has almost become a non-issue.
 
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