Phantom braking

[njmurvin]

Is this even a thing with MX? Most of the articles I’ve read mention M3 and MY. Does it only affect cars without radar? Do any/all MXs have radar? Does it happen with Autopilot or FSD or both?

I’m getting my 2019 Raven (no FSD) later this week and want to understand if this is something I need to be aware of.

 

[Bigriver]

Yes, phantom braking can be a thing with any Tesla model with adaptive cruise control that is a part of basic autopilot, enhanced AP and FSD. I have a 2017 Model X and 2018 Model 3, and they behave mostly the same. My personal experience is that I no longer experience the horrible, soul-jarring phantom braking that once occurred. They tended to be with shadows in the road or with overhead bridges, but were always extremely sudden and severe slow downs. Now, the only thing I experience are more like phantom hesitations. Annoying but not alarming. And very seldom.

A 2019 MX has radar, but the latest updates going out are reportedly disabling it on cars that have it. Both my cars have radar that was disabled about a year ago when I joined FSD Beta.

I am a big fan of autopilot. It has been a game changer for me for long trips. It is extremely good. But one still needs to pay attention, and there are times when you need to intervene.

 

[glide]

Is this even a thing with MX? Most of the articles I’ve read mention M3 and MY. Does it only affect cars without radar? Do any/all MXs have radar? Does it happen with Autopilot or FSD or both?

I’m getting my 2019 Raven (no FSD) later this week and want to understand if this is something I need to be aware of.

Yes it impacts all Tesla’s. And even if you have a model equipped with radar, that is going away as of software version 2022.20.9

 

[hemanthpai]

I have a 2020 MX and experience PB couple times a month, so it’s very real. I’ve stopped using Auto Pilot/Navigate on Auto Pilot. Regarding the previous post about PB going away with 2022.20.9, I recommend searching this forum for that firmware version. I, for one, will not be updating to that firmware for as long as I can.

 

[hemanthpai]

Sorry, I meant radar going away, not PB going away

 

[Bigriver]

I have a 2020 MX and experience PB couple times a month, so it’s very real. … I, for one, will not be updating to that firmware for as long as I can.

I would not fear the loss of the radar regarding phantom braking. My cars are better without the radar than they were with it.

 

[jboy210]

I would not fear the loss of the radar regarding phantom braking. My cars are better without the radar than they were with it.

Agreed. Radar is a blunt instrument. It says just yep there is something x meters ahead, no idea what it is so better slam on the brakes. I have a lot of phantom braking on my 2018 X 75. A hill with an overpass or rise in the middle divider would trigger it. Really bad on I-5 when you would be cruising at 80 and some one right behind you. It was like the car did it on its own to auto-brake check tailgaters.

 

[ngng]

Agreed. Radar is a blunt instrument. It says just yep there is something x meters ahead, no idea what it is so better slam on the brakes. I have a lot of phantom braking on my 2018 X 75. A hill with an overpass or rise in the middle divider would trigger it. Really bad on I-5 when you would be cruising at 80 and some one right behind you. It was like the car did it on its own to auto-brake check tailgaters.

I'll counter that with radar is excellent in limited viz. I routinely use cruise control, even at low speed in fog and snow as a safety net. Can't do that with vision.

 

[jboy210]

I'll counter that with radar is excellent in limited viz. I routinely use cruise control, even at low speed in fog and snow as a safety net. Can't do that with vision.

You are braver than me. I would never over drive what I can see. Growing up in the Central Valley of California which is infamous for fog you learn what a killer fog can be. Sometimes for weeks we would come to intersection and have to roll down the windows and listen for cross traffic. You went when it sounded empty, but knew you were taking a chance. And it seemed like everyone knew someone that got in a wreck or near miss in the fog.

 

[ngng]

You are braver than me. I would never over drive what I can see. Growing up in the Central Valley of California which is infamous for fog you learn what a killer fog can be. Sometimes for weeks we would come to intersection and have to roll down the windows and listen for cross traffic. You went when it sounded empty, but knew you were taking a chance. And it seemed like everyone knew someone that got in a wreck or near miss in the fog.

Sometimes you don't have a choice. I've been stick in pretty bad viz in Tahoe (not in the Tesla) and fog through Monterey or up in the Santa Cruz mountains.

 

[ApexProxy]

I have gotten a phantom brake on adaptive cruise about once every 500 or so miles. Each time in a different location but all on well marked very straight sections of freeway during the day with absolutely no actual reason. The last one slammed them so hard I disengaged and went manual for the remaining 50 miles for fear of having an actual heart attack. I keep my windshield pristine because I know the system is visual based so I have no idea what is triggering these PBs but it's making it hard to trust TACC for fear of causing me to be rear-ended or triggering road rage because someone thinks I was brake checking them. Things like this make me wonder how far off FSD really is if they cant even make TACC reliable.

I have on more than one occasion wished I had a dumb cruise control to use alternatively which is not a thought I expected to have.

Also a side note with TACC, on the freeway when someone changes lanes in front of me as I am following another car on setting 2 my car will hard regen and drop like 20MPH rapidly as though it had no idea what the other car was doing and thought it was essential to restore following distance an nearly emergency rate. Almost as uncomfortable as PBs are and something humans would be criticized for doing.

 

[brainhouston]

It was like the car did it on its own to auto-brake check tailgaters.

Easter Egg feature

 

[RBinIL]

Experienced two on the same trip this week. Both were caused when going from asphalt to concrete bridges on the interstate. Been on that route more than once and never had it happen before.
My MY seems really buggy lately.

 

[ApexProxy]

So after getting an update last weekend to go from 2022.23.101 to 2022.28.2 I have driven about 600 miles and have had no PBs or unexplained slowdowns on the same route in the same driving conditions. Previously I have had 1-2 events in that time frame. Hopefully this trend continues.

 

[Tokodave]

The past couple times I’ve driven from Butte, Montana, up to Helena I’ve had a phantom braking event, a relatively aggressive one at that, the exact same place, about two miles south of the exit off I 15 for Boulder Montana. Nothing the least bit obvious on or along the Interstate that would cause it? It’s a road I’ve driven countless times and it’s never happened before!

 

[Stuart1]

I have a 2020 Model S and on my 34 mile drive to work each day I would get phantom braking at the same two point on the road every day. As of the last software update a few days ago there is no phantom braking!!!!!

 

[brainhouston]

pre/post software versions would help