SalisburySam
Active Member
I done for my phantom braking what you suggest for navigation…and yet, over 3 years later, no resolution. Huh!
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1st phantom brake
- Thread starter mluu510
- Start date
Nolakai
Member
I've had phantom breaking a few times too. I don't use autopilot, but it's happened in adaptive cruise for me and always around overpasses. Ours is a radar-less 2021 Y. The first time was scary. The next times were just annoying because I quickly took myself out of cruise by hitting the right steering wheel toggle up. I wish Tesla had just regular, old-fashioned cruise control as an option. I like driving. I like paying attention. But it's nice to set a speed when I'm on a highway, especially to prevent myself from going too fast, which is really, really easy here in Southern California. I don't want any car breaking for me.
redmunds
Member
I've had this happen many times in my 2020 MS LR+ while using AP (not FSD). It's usually not what I would call "phantom" braking because it's obvious which vehicle (in different lane) that it's braking for, and not what I consider an actual threat, so it's more like "over reaction" braking. I just mash the electron pedal to let car know it's ok.
Yes of course I reported it to service, and yes of course he went through the logs. The technician then reeled off all the things that make TACC freak out including, shadows, pillars, large vehicles pulling over, worse in rain, basically all the situations we find ourselves. What he couldn’t do was offer a solution as I suspect he knew there wasn’t one. So reporting the PB appears futile. Until the regulator takes this issue seriously I suspect Tesla will ignore it, a bit like VW and the diesel scandal. Regrettably I think that TACC will never be free of PB.
SalisburySam
Active Member
As I said in post #21, yes, I have done this. I have since the beginning used the bug report feature until I learned that it really does little, but still do it nonetheless out of habit and the fact that I’m really good at it from all the practice. Service calls (4 over the years on this topic alone) have resulted in exactly what you’d expect: denial, explanation of what I did wrong, lists of obvious causes like overpasses, and that an upcoming firmware update will fix. That is, the expected humma, humma, yatta, yatta, botta bing botta boom. Load of crap. Either fixing this is (a) rationalized by Tesla as a non-problem, (b) it enjoys an extremely low priority behind the next Easter egg, or (3) it is unfixable with existing sensors, hardware, and software. Many of us thought the radar was causing phantom braking but recent vehicles without radar, and radar-equipped vehicles with software versions that don’t use the radar, refute that. At this point I agree with @rt29781 that TACC is at fault and will most likely never be fixed.
So what to do? As I’ve mentioned before, with passengers I just don’t use it, and since you have to use TACC before any of the other FSD-ish “features” I don’t use them either, hence my comment about not getting much for my EAP/FSD “investment.” The only real solution that I see is an option for dumb cruise control to disable the TA stuff as desired. At this point I chalk up Tesla’s refusal to do so as sheer arrogance, much like Apple’s “courageous” (their word) move to eliminate headphone jacks from mobile devices a few years back. Another load of crap. Yeah, I’m a little bitter about this. Totally spoils an otherwise amazing vehicle.
As a side but pertinent note: earlier in my ownership I frequently gave others a ride in my car to share the excitement. Whether they or I were driving, phantom braking happened on almost every test drive for them. Initial excitement immediately turned to WTF moments and instant turn-off. I know I lost more than one referral from this fact alone.
Bottom line: I know @haroldo that phantom braking is not a problem for you, and I applaud your fortune. But please respect that for me, and apparently others, it is a huge problem, a most unwelcome one, and its unfailing recurrences are constant reminders of an unsolvable annoyance that no other car ever experiences. My Model 3 is my 26th owned personal vehicle. It was very close to my favorite of all. It is no longer.
This happens on my 3 also. What I do not understand is why the great and masterful Musk has not addressed this yet. I have other gas cars with adaptive cruise and they never do this. I guess Tes;la has some catching up to do.
Nolakai
Member
Yes, 'overreaction' breaking is a better way to describe what I've experienced too,
Nolakai
Member
Personally, I would love a 'dumb' cruise control option. I just want my speed to be capped and held steady when I'm on an open road.
I understand completely and am not trying to belittle the issue.
My main (actually, only) point, which I’ll repeat, is to ask how long it took to take corrective action. Did the car slow drastically (70 MPH down to 50)? Did it brake for a second or two?
I’m 63, while I‘ve never had cat like reflexes, when my car brakes, I’ve been able to override before it dropped (guessing here) ~5 MPH, dangerous enough to cause problems for a tailgater, but not as much under normal traffic conditions. Generally speaking, when I have an annoying tailgater, traffic is very heavy at higher speeds, or notice an aggressive driver, I usually click up to turn off automatic driving and take over. (Probably good advice to all owners)
As an experiment, on an empty road, I let car “figure it out“. It slowed for a second or two, down about 10 MPH, and then resumed driving normally. I understand every situation is different, but that’s the only time I didn’t override.
When the car brakes, how much did speed drop? How long before you took corrective action?
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As fate would have it a few minutes after making the post above, I was on an empty road, using automated driving.
A truck in front of me was doing 70, I passed it with my TACC set at 72 miles an hour.
When I was about six car lengths ahead of the truck (I waited a few seconds before confirming the lane change) I moved into the truck's lane. A few seconds later my car started to brake.
I quickly pulsed the accelerator to override, and glanced at the screen, the car was at 69 miles an hour. I didn't push down on the pedal to accelerate, rather I just tapped to override. The speed shown was not affected by my override.
From this, extremely unscientific experiment, it appears that the extent of the phantom braking incident (with an alert driver) was 3 miles an hour, and, if I had to guess, under 1/2 second.
Yes, unanticipated braking is not a great situation, it’s obviously a problem, and a widely known issue. But everyone reading this thread is aware of the situation, and should be prepared. Those not reading forums, similarly, should be alert and prepared to take over for any unanticipated events.
A truck in front of me was doing 70, I passed it with my TACC set at 72 miles an hour.
When I was about six car lengths ahead of the truck (I waited a few seconds before confirming the lane change) I moved into the truck's lane. A few seconds later my car started to brake.
I quickly pulsed the accelerator to override, and glanced at the screen, the car was at 69 miles an hour. I didn't push down on the pedal to accelerate, rather I just tapped to override. The speed shown was not affected by my override.
From this, extremely unscientific experiment, it appears that the extent of the phantom braking incident (with an alert driver) was 3 miles an hour, and, if I had to guess, under 1/2 second.
Yes, unanticipated braking is not a great situation, it’s obviously a problem, and a widely known issue. But everyone reading this thread is aware of the situation, and should be prepared. Those not reading forums, similarly, should be alert and prepared to take over for any unanticipated events.
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SalisburySam
Active Member
I correct immediately, whatever that is in time so I don’t allow a big drop in speed. In traffic not requiring an immediate correction such as no one behind or around me I hold back the correction to see what the car actually does. USUALLY the braking is pretty hard and fast, going down from 65-70mph to 45-50mph in a second or two, so fairly violent and certainly so for passengers. With traffic around me my initial reaction is go pedal correction, then disable TACC with the stalk or brake pedal tap, a lot of swearing, another bug report, more swearing, and continuing on my travel. I have also noticed that my verbal wrath now includes statements as to what brand of car my next vehicle will NOT be.
That's interesting, I have a 2021 and the braking, while startling, is nowhere near as aggressive as your experience.
From your profile, it looks like you have a 2018, right? I wonder if the car's production year matters?
If I had to guess, when I let it slow without overriding, it went from 65-70 to 55-60 in a second or two, definitely braking, but not anywhere as severe as your car.
Next time I'll try to pay more attention (and set a Bug Report, so service can let me know the exact details).
On another topic, you got a cute dog, but black on black is tough to see (one of the advantages of a white dog!). How about updating your avatar with a flash photo?
SalisburySam
Active Member
Thank you. She’s a 14-year-old flat-coated retriever sitting on a dark leather couch looking out the window. Yeah, photography is not a strong suit and I was lucky enough to get an in-focus picture at all given the shaky way I hold a smartphone camera. Maybe I’ll use a better photo of our other dog, a 6-year-old black and tan Shiloh Shepherd. Or, I might try for a view with better lighting, but I’ll need to find one of those evasive round tuits laying around…no guarantees. Can’t do anything until I get a round tuit.
And yes, my car was manufactured in 06/2018. No idea how that affects anything other than I’m glad I have the no-additional-cost perpetual updates for satellite mapping, traffic, and whatever else comes with that nowadays.
I have a 2021 car and agree with SalisburySam the braking is very aggressive and scares the hell out of my wife. Scaring my wife is not a good thing and will be the demise of this Tesla.
Well, that ruins my theory.
I have Model 3 (June 2021). When it braked, it felt like the car was slowing, definitely not slamming on the brakes.
When I let the car continue braking (no override), it acted like it was confused ... like when there's an extra wide lane and it's not sure where to go... and slows. Definitely not aggressive, but not passive (regen) slowing either, if that makes any sense.
After a second, or so, it stops braking as it realized the presumed threat was not valid and then resumed traveling.
I've had similar confusion when the car missed an exit service road, but neared to area where the cloverleaf was.
Have you allowed the car to figure it out? How long did it brake before realizing its mistake?
I also have a June 2021 (Model Y). We both have Vision only. My experience is like yours, it rarely happens, and when it does, it is not very severe for me or my wife. I do have stopping for stopsigns/lights off, it seemed to be slightly worse with that on.
Maybe that's a factor? I set up a separate thread Phantom braking survey to see if there's a correlation
clydeiii
Member
Seems very unlikely year and model do not matter. All that matters, most likely, is software. And they are working around the clock to make it better.
clydeiii
Member
I bet whatever is "felt like the car is slowing" to some is "slamming on the breaks" to others.
I also think geography influences this. I very rarely experience phantom breaking here in MD but I bet it's much worse on other roads.
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