Ghost Braking Danger on Cruise Control

[ElectricIAC]

Worst is when on a newly built or expanded road and the car hasn’t a clue of the speed limit (because GPS) and “panic brakes” down to 50 from 75. SO annoying..

 

[nj1266]

Does this behavior go away if we disable Automatic Emergency Braking?

 

[Fernand]

FWIW I don't like "it". New HW3 and 2020.24.6.4

I drove ~ 180 miles in NOA on freeways today. I had no "phantom braking". But a lot of little regressed behaviors. The programmers seem to be changing a lot of things at once, and there are side-effects.

Hard to summarize, but it's changed a lot. It adds up to sloppy like I haven't seen in a long time. It was so smart and smooth a few updates back with my HW2.5, and now it made it difficult to relax.

New users ! hang in there, this isn't "as good as it gets". We've had bad spells before; obviously they're working on it.
.

 

[QuickOne]

I've had my M3 for about a month. Just took a 3200 mile road trip from Massachusetts to Kansas and back.
During this drive, I was on 2020.24.6.1 and I had multiple panic braking instances, all on the Interstates.
It seemed to me that it was when we were on a slight (ever so slight) downgrade near anything that cast a shadow.
From 80 to near 30 almost instantly isn't something to be ignored, especially with others behind you.
I also have noticed that the M3 will slow if a vehicle is in the right lane and I am pulling past it. Not every time, but often enough that I notice.

That one is the same I experienced on my '18 Honda Accord Touring. The response from Honda was 'Not reproduceable'
I trust Tesla to overcome this, but scary as all get out until they do. A bit dangerous too.

 

[Fernand]

3200 Miles? Oy, Mate, you probably just drive too much

 

[CertLive]

FWIW I don't like "it". New HW3 and 2020.24.6.4

I drove ~ 180 miles in NOA on freeways today. I had no "phantom braking". But a lot of little regressed behaviors. The programmers seem to be changing a lot of things at once, and there are side-effects.

Hard to summarize, but it's changed a lot. It adds up to sloppy like I haven't seen in a long time. It was so smart and smooth a few updates back with my HW2.5, and now it made it difficult to relax.

New users ! hang in there, this isn't "as good as it gets". We've had bad spells before; obviously they're working on it.
.

You know I am on 2020.20.17 and it has the smoothest autopilot characteristics I have ever used so far. One phantom break because of loss of speed limit 70 to 45 attempt. Hit the throttle to stop the close car behind rear ending me and ended up doing 80 in a split second I hope not triggering a speed camera I saw the lines!

 

[Stellavator]

Owned my car for almost 2 years now and have never had phantom braking, until now. Since the latest 2020.24.6.4 it has happened twice. And autopilot is just generally a little sloppier on the road. Definitely some regression here with this update. Hopefully will be fixed soon.

 

[TLLMRRJ]

Owned my car for almost 2 years now and have never had phantom braking, until now. Since the latest 2020.24.6.4 it has happened twice. And autopilot is just generally a little sloppier on the road. Definitely some regression here with this update. Hopefully will be fixed soon.

I wonder if they accidentally left that out of the marketing of OTA updates? Yes, your car can get worse, not better, with an OTA. On those days it gets worse, it kinda makes you wish you stuck with an old school manufacturer that puts out more stable code than one that throws new versions over the fence willy nilly and then leaves you dumbfounded as to whether or not they know or care about the problems they introduced.

 

[ElectricIAC]

That's the fun of owning a Tesla. You never know when you're gonna hit 0/00 on the wheel.

 

[carlosnunezhtx]

The only phantom brake that I've experienced in the 800 miles of driving I've done with ours so far was under an overpass near our house at low speed, fortunately.

Regardless of Tesla employing more advanced technology, my wife’s 2017 Honda phantom brakes far less than my 2019 Model 3. IMO, Tesla should have already figured out how to handle shadows from an overpass, but here we are, a couple years later, we have HW3, and I still have multiple incidents of false positives during my drive. Don’t even get me started on how poor the BSW system is compared to my wife’s Honda.

I think Tesla's system phantom brakes because it heavily leans on cameras instead of sensors like most other TACC's do

 

[ElectricIAC]

A similar effect happens when it feels like tracking the car in the next lane over and decides to pace it. This was largely gone in 20.12 but returned with a vengeance in 24.xx

 

[Fernand]

Like a box of chocolates. I mean, it's usable if you know and ride your beast, but mine has a bit of that Covid on the brain. I used to NOA so relaxed and now it's a lot more work. Sigh. Fix it boys!
.
And girls.
.
And the nagging thought is "and I paid to get him/her that HW3, and maybe they didn't wear masks when they installed it". Or something. Sigh.

Yeah, my wife's Honda seldom brakes or wavers. It's go no AP or fancy CC at all. Just my wife.
.

 

[SlimJim]

interestingly, I have not experienced any phantom braking in my new Tesla in 1000 miles. I am using AP everyday now.

 

[Fernand]

Even though I'm annoyed at the NOA regressions in 2020.24.6.4, I'm not having any "phantom braking" now either. Never had that problem.

It's bizarre how some people get a lot. I've had maybe 3-4 in a year and a half, all but one in early 2019. And even then they were plausible slowdowns in ambiguous situations. Never ever anything like suddenly going from 75 to 30 MPH, as one person described.

I'm driving in Northern California to Nevada. Maybe that helps. @SlimJim where do you drive?
.

 

[john5520]

Makes you wonder how thorough their testing is.

Even though I'm annoyed at the NOA regressions in 2020.24.6.4, I'm not having any "phantom braking" now either. Never had that problem.

It's bizarre how some people get a lot. I've had maybe 3-4 in a year and a half, all but one in early 2019. And even then they were plausible slowdowns in ambiguous situations. Never ever anything like suddenly going from 75 to 30 MPH, as one person described.

I'm driving in Northern California to Nevada. Maybe that helps. @SlimJim where do you drive?
.

What roads do you drive on often?

 

[Fernand]

Makes you wonder how thorough their testing is.
What roads do you drive on often?

Mostly NOA on freeways in the SF Bay Area. Also AP on surface boulevards and some back roads and highways.

It's certainly not un-thorough testing. It's an immensely complex program, and many complex cases interact. You make one thing more proactive, and something else suffers, like a complicated whack a mole. That's software reality.

I suspect the Bay Area has more complete speed limit mapping than other regions, that might be a factor, and why some people have more events.
.

 

[Silverpnt01]

I've had my current m3p for a month and have encountered several phantom breaking incidents. It appears to mainly do it around overpasses. I would think the car thinks the shadow is something it's gonna hit.

It's dangerous, I've almost been rear ended and then the other vehicle thinks your an idiot.

 

[Hyacinth416]

I experienced phantom braking on the highway with no overpass in sight recently. It was as if someone slammed the brakes, my foot was hovering over the accelerator (pure luck) and I managed to floor it almost immediately but it sure freaked the wife out. I also experience deceleration when the car thinks the speed limit changes from 100km/h to 70km/h, not sure why this happens but it does happen frequently in the same spots.