Has anyone heard of a Tesla being rear ended because of phantom braking?

[enemji]

It doesn't imply that at all.

It does to me.

 

[Frank Langella]

It does to me

It’s phantom braking, not phantom stopping.

 

[derotam]

It’s phantom braking, not phantom stopping.

Phantom Slowing down is probably a better description of what is generally known as Phantom Braking. Reading "Braking" so literally to mean using the physical brakes is a bit of a stretch....when talking specifically about how a TESLA works.

Now blended brakes may cause a operating mode but I currently do not have any repetitive PB spots I can use to test things out.

You should get SMT and record data for your PB events and post it. It would be interesting to see the actual deceleration curves and whether the car is or is not applying the physical brakes.

 

[zoomer0056]

Phantom Slowing down is probably a better description of what is generally known as Phantom Braking. Reading "Braking" so literally to mean using the physical brakes is a bit of a stretch....when talking specifically about how a TESLA works.

Now blended brakes may cause a operating mode but I currently do not have any repetitive PB spots I can use to test things out.

You should get SMT and record data for your PB events and post it. It would be interesting to see the actual deceleration curves and whether the car is or is not applying the physical brakes.

Wait ... what? I thought PB stood for phantom blending. No, that's what you get when trying to make a smoothie with a broken blender. Or, maybe it's the PB without the J, which would be good if it's toasted!

 

[JB47394]

I thought PB stood for phantom blending.

Pedantic Bickering

 

[zoomer0056]

Pedantic Bickering

Good one.

 

[sandman1330]

The argument about coming to a complete stop vs aggressively slowing down is kinda irrelevant, as I would venture to say everyone overrides the braking event with the accelerator before it gets to that point anyway. So whether it would have come to a complete stop or not, most don't even find out as they override first. It's the initial loss of 20mph in the time it takes to react that's jarring, and potentially dangerous.

All that being said, since FSDb 11.4.2, PB on my work commute has all but disappeared. I don't think I've had a single event since that update, though I haven't tried a longer road trip yet. So if you're not on FSDb, that updated software will (eventually) trickle down. Maybe the light is at the end of the tunnel... Or maybe the next update will bring it back. Here's hoping!

 

[Goose66]

There's a wide variety of definitions here on TMC. Some view it as any slowdown that's not expected, including just a few MPH. Others define it as a "slamming on the brakes" event where it drops 20+ MPH rapidly. And yet others see it as an AEB event (automatic emergency braking), which is a safety system designed to mitigate a collision.

I would think everyone who has experience phantom braking on NoA or FSDb v11+ knows what we are talking about when we say "phantom braking." No, it's not stopping. No, it's not slowing down for slow/stopped traffic in front of it or in the adjacent lanes. No, it's not AEB braking (because that wouldn't be "phantom" - there is a logical explanation). Phantom braking is when you are going down the highway at speed and the car for no apparent or visible reason dramatically sheds a material portion of it's speed in an instant.

Again, if you have experienced it, you would know it. And, to add my own 2 cents, if there is somebody tailgating you when it occurs, then there is a very real chance that they will interpret it as you brake-checking them, as has happened to me more than once. I have often thought it was related to shadows in that passing under a bridge on a sunny day is a frequent place where it occurred, but that is purely anecdotal and I don't think a definitive reason has been determined.

 

[Goose66]

All that being said, since FSDb 11.4.2, PB on my work commute has all but disappeared. I don't think I've had a single event since that update, though I haven't tried a longer road trip yet. So if you're not on FSDb, that updated software will (eventually) trickle down. Maybe the light is at the end of the tunnel... Or maybe the next update will bring it back. Here's hoping!

Phantom braking is still present on the highway in 11.4.2. Has it gotten better in 11.4.2? Maybe, but it's hard to tell. I haven't had frequent phantom braking problems (i.e. more than 2 over 100 miles or so) in a while now.

There is a "new" braking situation in 11.4.2 that is dangerous, although it might not qualify as "phantom braking." In 11.3.6, the car did a really good job of cheating over to the opposite lane line when passing a truck. So if the truck started to encroach into your lane, the car was already over a bit and wouldn't panic. However, for some reason in 11.4.2, they apparently removed or added some latency to the "cheating to the outside of the lane" function while at the same time tweaking the lane encroachment detection function. Now if a truck starts to encroach in your lane while you're passing it, the car slows down dramatically (similar to phantom braking), which really makes no sense because the safest reaction is often to not only cheat over a little if able but to speed up to get around the truck. IMO, slamming on the brakes just makes it more likely that the truck will hit you if it continues to come over into your lane while also now making collisions with the cars behind you more likely as well. This is one of two "regressions" I have identified in 11.4.2.

 

[derotam]

Phantom braking is still present on the highway in 11.4.2. Has it gotten better in 11.4.2? Maybe, but it's hard to tell. I haven't had frequent phantom braking problems (i.e. more than 2 over 100 miles or so) in a while now.

There is a "new" braking situation in 11.4.2 that is dangerous, although it might not qualify as "phantom braking." In 11.3.6, the car did a really good job of cheating over to the opposite lane line when passing a truck. So if the truck started to encroach into your lane, the car was already over a bit and wouldn't panic. However, for some reason in 11.4.2, they apparently removed or added some latency to the "cheating to the outside of the lane" function while at the same time tweaking the lane encroachment detection function. Now if a truck starts to encroach in your lane while you're passing it, the car slows down dramatically (similar to phantom braking), which really makes no sense because the safest reaction is often to not only cheat over a little if able but to speed up to get around the truck. IMO, slamming on the brakes just makes it more likely that the truck will hit you if it continues to come over into your lane while also now making collisions with the cars behind you more likely as well. This is one of two "regressions" I have identified in 11.4.2.

Catch 22 however. If you are going the speed limit or are at your limit set for TACC the are you expecting the car to go faster than that? Violating your set speed isn't necessarily an issue, but violating the legal speed limit on its own would be a NHTSA recall just waiting to happen.

I understand your point and I agree with the idea...but laws, NHTSA, legal liability...

 

[Goose66]

Catch 22 however. If you are going the speed limit or are at your limit set for TACC the are you expecting the car to go faster than that? Violating your set speed isn't necessarily an issue, but violating the legal speed limit on its own would be a NHTSA recall just waiting to happen.

I understand your point and I agree with the idea...but laws, NHTSA, legal liability...

I get that, but even if driving at the set speed is making progress getting past (or passed?) the truck, it still dramatically slows down on the detected possible encroachment. I guess I feel like that would never be my choice unless I was in maybe the rear 1/5th of the truck - especially if there are cars on my tail. And like I said, I didn’t notice this behavior until 11.4.2, thus I consider it a regression.

 

[israndy]

The argument about coming to a complete stop vs aggressively slowing down is kinda irrelevant

I can't tell if that is in relation to my question, as I didn't ask if PB means coming to a stop or aggressively slowing

I asked if it was unexpected slowing or if it was throwing things off the seats slowing. I have NEVER experienced the latter but from all the complaining it sounds like that's what people get.

 

[Goose66]

I can't tell if that is in relation to my question, as I didn't ask if PB means coming to a stop or aggressively slowing

I asked if it was unexpected slowing or if it was throwing things off the seats slowing. I have NEVER experienced the latter but from all the complaining it sounds like that's what people get.

I would characterize it as any dramatic slowing that a human would never expect and would never do themselves unless they were hard braking for a visible obstacle. How much speed is reduced (and whether things fly off seats) just depends on how long the NNs think that something is there. Usually it is only for a moment and the car returns to the original speed. Another way to view it - both times it has happened with my wife in the car it's been alarming enough that she audibly gasps and then insists that I stop "playing with my car" while she's a passenger.

 

[enemji]

Phantom Slowing down is probably a better description of what is generally known as Phantom Braking. Reading "Braking" so literally to mean using the physical brakes is a bit of a stretch....when talking specifically about how a TESLA works.

Now blended brakes may cause a operating mode but I currently do not have any repetitive PB spots I can use to test things out.

You should get SMT and record data for your PB events and post it. It would be interesting to see the actual deceleration curves and whether the car is or is not applying the physical brakes.

Yes. You get it and articulated it very well.

 

[LadyOnikara]

I have only had one experience of "Phantom Braking". I had the TACC on and a car in the other lane was a little too close to the center line and Casper got scared and hit the brakes slightly. That's all.

 

[texas_star_TM3]

for what it's worth... PB on a hot summer day with mirages over the hot asphalt on an otherwise long and wide road stretch caused my Model 3 to go from 83mph to ~50mph *within seconds* ... on a MAJOR highway from Amarillo to Dallas-Ft.Worth.

yes, the brakes are applied. and yes - other cars honked at us....

Phantom Braking getting worse - any ideas on how to stop it?

Happens to me a lot in Texas in my 23 M3P. Ridiculous that Tesla cannot figure this out. We have a Volvo XC90 and Nissan Rogue that has adaptive cruise control, and this never happens. It would be nice if Tesla enabled a straight up cruise control setting to avoid this. As it stands now, it’s...

teslamotorsclub.com

 

[enemji]

for what it's worth... PB on a hot summer day with mirages over the hot asphalt on an otherwise long and wide road stretch caused my Model 3 to go from 83mph to ~50mph *within seconds* ... on a MAJOR highway from Amarillo to Dallas-Ft.Worth.

yes, the brakes are applied. and yes - other cars honked at us....

Phantom Braking getting worse - any ideas on how to stop it?

Happens to me a lot in Texas in my 23 M3P. Ridiculous that Tesla cannot figure this out. We have a Volvo XC90 and Nissan Rogue that has adaptive cruise control, and this never happens. It would be nice if Tesla enabled a straight up cruise control setting to avoid this. As it stands now, it’s...

teslamotorsclub.com

I was on the same road last week and had PB galore and it was not due to mirages, for sure.

 

[enemji]

Major Phantom Braking Issues

I agree. I also think the regen braking available to us humans is significantly reduced as compared to what the car can do on its own. I agree, and the deceleration curve definitely could be different as well. Hmm.., I need to find a strong repetitive PB spot and plot the deceleration and...

teslamotorsclub.com

 

[DPowers]

Phantom braking is unsettling and seems like it could cause a rear ending incident but I've yet to hear of a single case where this has happened. Out of the millions of miles that Teslas have driven with automation, there should be multiple reports of accidents if this were truly a problem. Could it be that it's not as dangerous as it appears? Perhaps the car takes into account the car behind before it decides to brake and doesn't do so if the rear car is too close.

BTW: I know about the 6 car pileup last Thanksgiving in the SF Bay Bridge tunnel. A Tesla changed lanes in front of a fast moving vehicle and then slows to a stop, causing the accident. The driver blamed FSD but Teslas use AP on that bridge, not FSD, so that's not possible. Also phantom braking incidents don't stop the car, they only retard the speed temporarily then continue at full speed. The full report of this incident has not been released and the driver's report is verifiably erroneous so phantom braking may not be the issue.

Phantom breaking is unsettling and dangerous to us and everyone around us. Tesla needs to own and resolve the issue. At some point, one or more attorneys will subpoena video to prove that it is a safety hazard for us as Tesla owners/drivers and for those driving around us.

 

[smogne41]

Phantom breaking is unsettling and dangerous to us and everyone around us. Tesla needs to own and resolve the issue. At some point, one or more attorneys will subpoena video to prove that it is a safety hazard for us as Tesla owners/drivers and for those driving around us.

It has been a problem for >6 years. They obviously can't fix it, at lest with the current approaches or they would have already.