Just come across the phantom braking issue, considering canceling my order

[mscott]

So here's my issue with the whole "just learn and be prepared" to overcome PB responses: What I've learned so far is that bridge guard rails and "mirage/oasis effect" on the road seem to be common triggers. (I've not been able to correlate any of my PB events with shadows, but I wouldn't rule it out.) Well, especially on roads I don't travel frequently (i.e., pretty much all of them when I take a road trip, which is when I most want to use AP), I don't know which specific possible triggers will cause the car to PB. (And bridges are amazingly common on highways once you are forced to look for them!) Therefore, I have to hover my foot over the accelerator to be ready to respond quickly to any PB event. On long drives, I find that very uncomfortable.

My family and I just completed two road trips this summer in my new MSLR, one was 3,700 miles and the other was 5,300 miles. The PB was bad enough (at least one event between every SC stop) that I eventually just stopped using AP/TACC and manually drove the car. I can deal with not using AP, but not using any kind of cruise control on a long drive is just plain medieval.

Yes, when I'm alone in the car I use TACC/AP more and "deal" with PB, but if I have a passenger in the car, no way I'm going to subject them to that crap.

Also, like a few others here, I came from an AP1 car in which I can't ever remember experiencing a PB event, ever. (It would sometimes lower the set speed on TACC, apparently due to the car thinking I was suddenly on a side street with a lower speed limit, but that slowing is much more gradual than most of my PB events.)

One other thing I've noticed is that when I do manually push the accelerator to get through a PB event, the car sometimes returns to aggressively slowing after I lift off the accelerator. It can do this for a mile or more. Sometimes I turn off AP/TACC and turn it all back on and that fixes it. Maybe that was a bug in the firmware I had at the time, IDK. Regardless, it's pathetic behavior for a $100K car.

 

[wadood]

Is this as bad as it sounds? Just came across some discussion from Tesla owners(!) who are really upset about the phantom braking that is still presently an issue. It sounds like a really scary problem. At this point I’m considering canceling my Tesla order because this is a hard safety dealbreaker I haven’t come across in any other vehicles I was cross-shopping. Is it only some some cars? I have a 22 Model S with only Autopilot on order.

First of all, phantom braking is not hard full stop on a highway! I have not experienced anything like that ever. However, on daily basis, I see brakes applied for no good reason, which slows down the car a bit. In almost all cases the car corrects itself, without me doing anything. I have MYLR and use FSD. I have driven from Toronto to New York, twice last month with zero interventions.

 

[cbdream99]

So here's my issue with the whole "just learn and be prepared" to overcome PB responses: What I've learned so far is that bridge guard rails and "mirage/oasis effect" on the road seem to be common triggers. (I've not been able to correlate any of my PB events with shadows, but I wouldn't rule it out.) Well, especially on roads I don't travel frequently (i.e., pretty much all of them when I take a road trip, which is when I most want to use AP), I don't know which specific possible triggers will cause the car to PB. (And bridges are amazingly common on highways once you are forced to look for them!) Therefore, I have to hover my foot over the accelerator to be ready to respond quickly to any PB event. On long drives, I find that very uncomfortable.

My family and I just completed two road trips this summer in my new MSLR, one was 3,700 miles and the other was 5,300 miles. The PB was bad enough (at least one event between every SC stop) that I eventually just stopped using AP/TACC and manually drove the car. I can deal with not using AP, but not using any kind of cruise control on a long drive is just plain medieval.

Yes, when I'm alone in the car I use TACC/AP more and "deal" with PB, but if I have a passenger in the car, no way I'm going to subject them to that crap.

Also, like a few others here, I came from an AP1 car in which I can't ever remember experiencing a PB event, ever. (It would sometimes lower the set speed on TACC, apparently due to the car thinking I was suddenly on a side street with a lower speed limit, but that slowing is much more gradual than most of my PB events.)

One other thing I've noticed is that when I do manually push the accelerator to get through a PB event, the car sometimes returns to aggressively slowing after I lift off the accelerator. It can do this for a mile or more. Sometimes I turn off AP/TACC and turn it all back on and that fixes it. Maybe that was a bug in the firmware I had at the time, IDK. Regardless, it's pathetic behavior for a $100K car.

Before updating to the FSD beta, I hardly faced any PB. Now, it's a common theme, more than likely it's a bug. Hopefully, the new version coming out soon will fix or improve it.

 

[Tam]

...In almost all cases the car corrects itself, without me doing anything...

An example in the New York Times is that the Tesla drove at 77 MPH and slowed down to 55 MPH, then got hit from behind.

Can Tesla Data Help Us Understand Car Crashes?

This is today in https://www.nytimes.com/ Video : https://vp.nyt.com/video/2022/08/16/101991_1_tesla-crash-hp-promo_wg_720p.mp4 We had a similar situation with our Model Y. While in Self Driving on I95 in South Carolina, the car braked hard because there was a car stopped on the left grass...

teslamotorsclub.com

AEB is not phantom braking. You are confused.

Whatever the names, some would not call that "phantom braking." Still, the fact that when there should not be any reduction in the speed if driven by humans but to the machine, it's perfectly reasonable for the automation to do that, then it's a problem regardless what the name is "phantom braking" or not: It's a reduction of speed that a human driver would not do.

 

[AndrewZ]

The NHTSA is calling this "unexpected brake activation" but also refers to phantom braking.

If anyone is interested, this was the NHTSA's request for information under the phantom braking investigation after receiving 758 complaint reports on 2021-2022 Models Y and 3 as of May

https://static.nhtsa.gov/odi/inv/2022/INIM-PE22002-87085.pdf

They're asking for very specific stuff including deep technical items related to autonomous driving assist systems. With a lawsuit in the works, I imagine they'll ratchet this up as the NHTSA often moves specifically in response to action in the legal realm.

 

[_Redshift_]

Ah this was my other consideration. I get lane centering/adaptive cruise control in my Hyundai for the reduce in mental stress while driving, but I NEVER try to do something else other than being alert to the road while driving. I was thinking this phantom braking could be coming across more severe for the Tesla drivers who treat driving as something they now no longer need to be as attentive to. But I would always be attentive. If it's really simple to catch it and accelerate if you're constantly paying attention to the road, that's understandable. I just wonder then how freaky/sudden/startling is the phantom braking? I've frequently seen people say it's startling, and many people in this thread are corroborating that and saying they turn off AP. Well, that would defeat the whole purpose of getting a Tesla, at least for my circumstances.

In My 2018 Model 3 I have had two instances of ‘slam on the brakes‘ at 75 mph or so on the freeways. The braking was strong enough to throw you forward in you the seats.

Once there was family with me and the other time there wasn’t anyone else with me. Due to that event, my family now asks me not to engage the EAP when they are in the car. I turn it on all the time now, and my family has kind of become used to it.

That sudden braking has not occurred in the last 2 years. However, phantom braking thats not as severe has continued, and become more frequent with the past few software updates. When I am cruising at 70+ in the free and clear carpool lane, if the adjacent lane has a bit heavy traffic, the car brakes to slow down to 55 mph, which is annoying but not severe, since the cars following you get very annoyed by that behavior.

There is a particular section of the road near my office where carpool lane starts as a new lane. The car used to always slow from 70 to 50 mph there. Couple of years back, that went away. However, with the last few updates, it is back again.

This is the annoying part, the software updates seems to regress sometimes.

 

[_Redshift_]

That’s because you don’t recognize it soon enough or know the places to avoid it in the first place. It takes a LOT of time. I used to be outraged about it. Now it’s totally a non issue. My wife used to hate too. Now she doesn’t even notice it. And it doesn’t take white knuckled to catch it. It just comes natural after a lot of driving with it.

It also has improved quite a bit over time.

Be great if it never did it all. But it’s the software erroring on the cautious side.

I don’t think you can blithely conclude that it’s ‘software erroring on the cautious side’.

It can be equally possible to have a glitch in the software, a bug in the algorithms, or camera input sensing that had some problem (like glare, shadow, whatever).

 

[White Shadow]

Phantom brakes happen in all cars that use radar for collision avoidance technology (including Automatic Emergency Braking)....

Gotta disagree. I've had a 5 vehicles (cars and SUVs, I always have one of each at all times) over the last ten years and all of them have this technology and none of them ever had any kind of phantom braking.

 

[Tam]

Gotta disagree. I've had a 5 vehicles (cars and SUVs, I always have one of each at all times) over the last ten years and all of them have this technology and none of them ever had any kind of phantom braking.

I admit that my statement is too absolute, so I was wrong.

It should be rephrased that phantom brakes may happen due to conventional radar technology, but not in all cars.

Now that we have 4D-RADAR, it's likely to eliminate phantom brakes to near zero.

Countering the ‘Phantom Braking’ Phenomenon

"It is one of the only radars on the market today that can detect objects accurately with almost no instances of false alarms, eliminating the issue of phantom braking and enhancing safety for the driver and others on the road."

 

[alangold]

Well said. The sky definitely isn’t falling with the phantom braking issue. I just don’t use the Autopilot. Problem solved. I didn’t buy FSD because the technology just isn’t there yet. At least not for me. Everything else about my Tesla makes up for the Phantom Braking, and all the other annoyances. When a competitor comes out with a car that comes close to competing with my Tesla, I’ll definitely take a look at it. Until then, the car is awesome and I don’t mind driving “manually”.

This blog has had a huge response from wild to mild - I also thought about canceling my model 3 due to PB braking issues - I don’t rely on cruise control - but having your foot ready to intercede the car makes no sense for me - I do want to try it sometime with no traffic -

 

[vonklarp]

Got my 2022 Model y in April, took my first road trip from Oregon to Wyoming in July. Great trip except for the phantom breaking, 6 or so in all, one was just a tap, one was just a mild slow down, and the rest a sudden deceleration that really scared me. All on I84 with a speed limit of 80 while driving ~75 using TACC only. Filed a NTSHA report upon my return. I would not hesitate to buy Tesla again but don't us AP much anymore.

 

[beatle]

Is PB more prevalent on two lane roads or divided highways? The former I don't really care about so much, but the latter is what AP is made for IMO.

FWIW I think I have experienced PB once or twice on my AP1 car in the past 3 years and 34k miles. I use it frequently.

 

[BitJam]

I do about 80 to 85% of my driving with AP enabled. When I got my car a year ago PB happened often enough to be annoying. Then roughly 6 or so months ago it was almost only happening when I was on a two-lane road and a large truck was approaching from the opposite direction. I can see the truck coming way before the PB happens so I just put my foot lightly on the accelerator and the problem was solved. IMO a proactive approach like this can be the key to making PB a minor nuisance. Same thing when the car wants to move into the wrong lane on my regular route. I know exactly where it's going to happen so I avoid it.

For the past 3 months or so I've had almost no phantom braking. No issues with trucks in the opposite lane. I'm sure this is a function of where I drive. Still, for where I drive it has almost entirely gone away. For example on the small, lonely two-lane road I take to drive home there is a small hill or rise. The car would consistently brake on the hill probably because it was not certain what was on the other side. It stopped doing that about 6 months ago. My subjective, anecdotal experience is that PB has gotten much better during the year I've had my car.

If you are considering cancelling an order because of PB concerns then I suggest you take a test drive on the roads where your drive the most (I realize this is not possible everywhere, including where I live).

 

[ruby110]

This is exactly my experience. It doesn't happen all that often, but it's highly unpredictable. I had it happen numerous times (10+) driving across Kansas on I-70 where there was literally nobody else in sight, so these are not like—as some others have suggested—a case of me not seeing something and the car saving me.

On the highway, it's bridge guard rails that seemed to provoke PB most frequently, but it also seems that the "oasis effect" can trigger it. Also, it does seem to happen a lot less often in heavy traffic. I haven't ever had a PB event in stop-and-go traffic, and the more cars there are around me the less it happens.

My experience driving across country is that PB occurs on roads with no traffic ahead of me. It appears to me that it’s a line of site issue. There is a rise in the road and the car doesn’t know the road continues. I turn TACC off if I’m not following someone. This is happening in a 2018 M3. I am confident this will be fixed but in the meantime it’s a serious issue. I like to use TACC to avoid speeding.

 

[Droschke]

AP1 with zero phantom braking when using the TACC or AP in the early years.

Now, it is very common, especially when the TACC is active and on 2-lane roads and when a car is parked on the shoulder, among other scenarios. The braking is very harsh and sudden. If I use the TACC on any 2-lane road I try my best to remember disabling it once I see a car parked on the roadside. The only thing changed during these years is the software.

 

[Mark II]

AEB is not phantom braking. You are confused.

If AEB triggers for no reason, then it is phantom braking, like other manufacturers cars. Google it. Just because your Tesla has never had PB without AP does not mean others may not have experienced it, or that it is not possible.

 

[mswlogo]

I don’t think you can blithely conclude that it’s ‘software erroring on the cautious side’.

It can be equally possible to have a glitch in the software, a bug in the algorithms, or camera input sensing that had some problem (like glare, shadow, whatever).

I’m sure it is a glitch like glare or something and it errors on the cautious side and assumes it’s an obstacle until it has confidence it’s not glare, shadow or whatever.

If it was simply a “bug” it would have been fixed eons ago. It’s partly limitations of the sensors.

 

[roblab]

In my experience, phantom braking happens mainly on single lane roads with curves and hills and dips. The car can't see, so thinks the pickup coming your way is on your side --- until it suddenly can see and lets off the brakes.

Tesla set up NoA and Autopilot to be used on dual lane highways or bigger, where the car can see the road. It has little problem driving smoothly and surely on these roads.

I haven't had any phantom braking issues when I refrain from using autopilot on single lane roads.

As to bullsheiss, some people bring their own. I prefer to stay above that.

 

[mswlogo]

Tesla set up NoA and Autopilot to be used on dual lane highways or bigger, where the car can see the road. It has little problem driving smoothly and surely on these roads.

And that’s exactly what it was designed for and the only place I use it.

FSD Beta is for off highway. Still work in progress.

Folks complaining about PB on anything but multi lane highways should say so.

 

[Wol747]

My 2020 S used to have PB episodes on auto fairly frequently - so much so that 'er upstairs won't let me use autopilot at all when she's with me (which is virtually all the time, so bye bye $8500 FWIW.)
This last year I've had the occasional one that's a very minor and momentary slow down with the exception of one hard braking a month ago. None have had any obvious reason such as bridges, shadows, other traffic etc.