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Phantom Braking vs TACC in Late 2020

Maxpilot

Member
Jul 27, 2020
53
59
Kansas
I'm having a little buyer's remorse for getting FSD. I don't use it because it is so buggy. I enjoy driving the car. I really don't need FSD.
 

Trilodroid

Member
Nov 30, 2020
18
5
USA
Reporting back continued, forgot one thing... it did slow down on large highways once for a lane merging into my lane. I take it this is some overly safe driving in case merging cars are hidden... ? Also had lane departure warnings on rough roads (did I mention this) driving around 45 mph, that had some odd lane lines and road damage in the middle of the road.

Watching videos, I can definitely see how it is harder for the AP to know what to do when there is a hill plus a curve ahead, which makes the illusion of oncoming vehicles appearing to be driving in your lane coming right at you from a distance. But somehow our human brains can decipher this situation, so AP needs to learn how to do the same. Now the overhead branches and overpasses... I don't get that at all. Is a shadow appearing as a 18-wheeler/lorry to the AI or something?
 

goldengate

Member
May 9, 2018
362
429
san rafael,ca
95% of my drives I don't get PB. I noticed that it seems to happen when going up hills (it only slows down) or making right curves with another vehicle on the opposite lane. (All of these happen on two lane roads)

On highways I have very little issues with PB.

100% agree w/the above. the right curve with another vehicle on opposite side is where I most often see it.
I had a scary incident last week with someone who was following too closely... I wondered if he was a DUI since he was an older man with a handicapped placard in an older beat up car and didn't seem to be the type to tailgate ... I was in the slow lane on the freeway.
Just as I was thinking "I hope this damn car doesn't pick now to do a PB" of course 10 seconds later BOOM it did it... luckily I had my foot over the accelerator and within a second had it back to 65, but it was really scary and he backed off, probably thinking I was brake checking him.

Having owned the car since 2018 and loving every minute of it for the most part, this PB is my lingering concern. Since I am on hardware 2.5 I fear it will never be completely fixed for my car...
 

Phlier

Bluebird
Jun 12, 2019
1,475
1,847
Utah
So I have been watching a few beta testers FSD footage on Youtube as of last night, just recently it seems there isn't much if any phantom braking. I have actually seen no phantom braking scanning through videos of 21020.44.15.3 and 21020.44.15.4. FSD has obviously come a long way from just a couple of months ago, so I am hopeful it will fix general AP as well.
I've been watching a ton of those FSD beta videos, too, and have yet to see a PB event in any of them. One of the guys did actually state that he's been in the program since it was first released and has yet to have a PB event with the beta.

PB has really been a mystery. A few months ago, I noticed that after the most recent firmware update, the three areas that *always* cause PB events and the two areas that most of the time caused PB events were completely fixed. I immediately came to the forums to see if there were others reporting decreased PB events, just to find out that it seemed like the majority of the PB related posts were from guys/gals reporting that it was worse than the previous firmware version.

IMO, it's too early to completely write off HW 2.5 for getting PB fixed. Sure, we know that HW 2.5 won't have the horsepower needed for FSD, but that doesn't mean that it doesn't have the power needed to implement the new TACC code. This is definitely going to be a wait-and-see thing for HW 2.5.
 
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Brexpat

Member
Sep 4, 2019
16
4
NL
On the cusp of getting a new car, and there is so much about the Tesla Model 3 that I love. The one thing I'm worried about is phantom braking during TACC (not talking steering assist, nor FSD). I've been doing a little digging... OK a lot of digging, and it is clear that with each software update something like phantom braking may change dramatically. What I have seen is in July 2020 there was a big update where it was more of an issue. I gather that it has gotten better since then, so I do not want to be worried about issues that are going away or do not apply to me (for instance TelsaBjorn is great on his phantom braking reporting, but I personally don't need to worry about narrow lanes and big trucks on small roads in Norway).

As it is exceptionally hard to get a test drive where I live I need help... can a few posters give me their current take on it per the following... and maybe throw in what sort of town/city/state/country you drive in if you don't mind sharing:

1. TACC and phantom braking on interstate style highways in late 2020.
2. TACC and phantom braking on the way to work. And have you gotten a consistent false positive/phantom brake so you know the one or two spots to watch out for? Does this change with each update?
3. The state of phantom braking over the course of your ownership of a Tesla.
4. Does turning off AEB change anything currently? From February 2020 there is a Youtube video where someone turned off Automatic Emergency Braking and it didn't actually turn that feature off. Guessing that was a temp bug.
5. Would you say staying on the conservative software updates actually avoids major mood swings of AP or is it still hit or miss?
6. Does phantom braking happen more or less if you have more distance or less distance from the car in front of you?

What would be ideal for a buyer like myself is the ability to engage TACC such that it only worries about the car you are following and ignores everything else. That option would be perfect for 90% of my car-assisted driving.
Buy something else. The car has too many bugs and is borderline unfit for purpose. Fast in a straight line though.
 

jeffnz

Member
Aug 17, 2019
97
19
New Zealand
Just got back from a 5800km road trip with nearly all on 2 lane narrow and winding roads. Used TACC a lot of the time. Had a few unexpected slow downs (not jamming hard on the brakes though) and each was related to coming up to the top of a blind hill with a truck in the oncoming lane. Something I hadn't seen before was it would slow down a little as it approached sharp curves. I didn't realize TACC did that and it was nice.

And for the times I was on a divided highway it was perfect on those types of roads
 
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Shelburne

Member
Mar 9, 2021
84
58
Shelburne Falls, MA
On the cusp of getting a new car, and there is so much about the Tesla Model 3 that I love. The one thing I'm worried about is phantom braking during TACC (not talking steering assist, nor FSD). I've been doing a little digging... OK a lot of digging, and it is clear that with each software update something like phantom braking may change dramatically. What I have seen is in July 2020 there was a big update where it was more of an issue. I gather that it has gotten better since then, so I do not want to be worried about issues that are going away or do not apply to me (for instance TelsaBjorn is great on his phantom braking reporting, but I personally don't need to worry about narrow lanes and big trucks on small roads in Norway).

As it is exceptionally hard to get a test drive where I live I need help... can a few posters give me their current take on it per the following... and maybe throw in what sort of town/city/state/country you drive in if you don't mind sharing:

1. TACC and phantom braking on interstate style highways in late 2020.
2. TACC and phantom braking on the way to work. And have you gotten a consistent false positive/phantom brake so you know the one or two spots to watch out for? Does this change with each update?
3. The state of phantom braking over the course of your ownership of a Tesla.
4. Does turning off AEB change anything currently? From February 2020 there is a Youtube video where someone turned off Automatic Emergency Braking and it didn't actually turn that feature off. Guessing that was a temp bug.
5. Would you say staying on the conservative software updates actually avoids major mood swings of AP or is it still hit or miss?
6. Does phantom braking happen more or less if you have more distance or less distance from the car in front of you?

What would be ideal for a buyer like myself is the ability to engage TACC such that it only worries about the car you are following and ignores everything else. That option would be perfect for 90% of my car-assisted driving.
We bought our 2020 M3 LR in September. Most of our driving is done on rural roads with speed limits no higher than 50mph. When we do go on the interstate, we have never experienced phantom braking, even while going under overpasses. But it's another matter on the rural roads. The car tends to get confused and hit the brakes only occasionally, but it's always while going around a sweeping curve with a car coming in the other direction. There is one stretch of road we often drive, with a sweeping curve, and another road that merges into it on the outside of that curve. If there is a car traveling toward us around that curve, and a car waiting to enter from the other road, we almost always experience some phantom braking. It's gotten to the point where I now take the car out of TACC before approaching that stretch of road. Our previous car was a 2017 Volvo S60. We never had a phantom braking issue with that car on any kind of road when we were using it's Adaptive Cruise Control. Perhaps Tesla is just being overly cautious, but I think that TACC does need some improving.
 

TexasTezla

Member
Feb 28, 2020
58
29
Texas
So far I have driven approx. 10k miles on mostly highway driving using AP. Total stress reliever for me. Whereas I used to arrive tired after an 8 hour stretch I now arrive feeling OK! I've had a couple of PB events but nothing that I could class as dangerous. Personally I think AP is great and well worth the $5k I paid in 2019.
 

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