My 100D model S regularly brakes hard for no reason at all when in FSD. Have others noticed this?

[Hans58]

For the past few weeks I've noticed extremely erratic braking when in FSD. The car is going along just fine and it will all of a sudden, for no reason at all, slam the brakes and slow down roughly 15-20 mph. It is dangerous and has almost caused an accident twice

 

[Tam]

For the past few weeks I've noticed extremely erratic braking when in FSD. The car is going along just fine and it will all of a sudden, for no reason at all, slam the brakes and slow down roughly 15-20 mph. It is dangerous and has almost caused an accident twice

That is not new.

I knew it when I got it since 2017.

For now, the option is to adapt to it or to just disable it and drive manually.

It's a beta after all.

 

[cookie99]

ah yes phantom braking, welcome to the forum!

it happens when you’re going through an overpass

 

[JimBob 909]

Last time it happened, I glanced down and the cruise control went from 65 in the circle to 40 in the circle. No idea why. When it does happen i hit the accelerator so I'm not rearended. My wife thinks I'm nuts and that I'm doing something to cause this.

 

[KArnold]

Are you near an exit ramp when it happens? Mine seem to - I'm thinking the car thinks you are exiting. Might just be me.

 

[BrianS85]

I’ve been thinking about upgrading my 2015 AP1 to something newer, with FSD, but all of these posts about phantom braking and lane centering are starting to make me think I should stick with AP1 for now. It would be very annoying to spend a bunch of money only to have a worse autopilot experience.

 

[Ostrichsak]

I’ve been thinking about upgrading my 2015 AP1 to something newer, with FSD, but all of these posts about phantom braking and lane centering are starting to make me think I should stick with AP1 for now. It would be very annoying to spend a bunch of money only to have a worse autopilot experience.

The lane centering issue is also present on AP1, although far less frequently. I've personally never experienced phantom breaking in an AP1 car nor if I heard too many references towards that though.

 

[headcase]

AP1 and previous AP2 car owner here. Sold the AP2 car due a few limitations, including frequent phantom braking (downright dangerous if a semi is directly behind you!), FSD still a fairytale, and poor performance of windshield wipers in the dark. Still content with my AP1.

 

[2101Guy]

shadows in road is a highly likely cause. The cameras sometimes think shadows on the road surface are objects

 

[jdw]

GPS inaccuracies will also do this - the car thinks you are on a different road and drops the speed limit.

 

[DerbyDave]

shadows in road is a highly likely cause. The cameras sometimes think shadows on the road surface are objects

I think this is likely true, and I can't understand why Tesla depends so much on visual data. It should also look at the radar to see if there is a big white truck overturned across the highway just in front of the car, or whether a shadow is an obstacle. FSD will never be reliable when so much emphasis is placed on visual data. It should never run into a stationary object across the road the size of a truck.

 

[Dss2000]

For the past few weeks I've noticed extremely erratic braking when in FSD. The car is going along just fine and it will all of a sudden, for no reason at all, slam the brakes and slow down roughly 15-20 mph. It is dangerous and has almost caused an accident twice

I used to have this in my Model S but seems to be better the last few months with software updates. Seems like when passing an offramp car would think it's on the offramp and adjust cruise control speed down to 45mph. Was better if I kept away from the right lane of the freeway. But It doesn't seem to do that as much in the past several months.
I do have a problem that after about 30 minute drive at freeway speeds when I get off on the off ramp it hard brakes when I let up on the accelerator. Seems to do this for about 5 minutes after getting off the freeway and then easing up on accelerator works fine. Anybody else have this issue or is it normal behavior?

 

[GreggF1]

I've driven an 8 hour trip on FSD and the only time my new car did this was when someone veered into my lane. For some reason the car 25% of the time will hit the brakes, and 75% of the time it will swerve if it can. We use FSD all the time and have not experienced the car stopping for no reason - it always seem attributed to some event.

 

[AmpedRealtor]

For the past few weeks I've noticed extremely erratic braking when in FSD. The car is going along just fine and it will all of a sudden, for no reason at all, slam the brakes and slow down roughly 15-20 mph. It is dangerous and has almost caused an accident twice

Maybe you shouldn't be putting your life in the hands of Tesla's beta-ware. Both FSD and AP are "beta" products and you must accept that disclosure when you enable those features. Don't be surprised if it kills you as it has others. My advice would be to stop using it for anything but adaptive cruise. The other features simply do not work and are not worth risking life and property (for which YOU, the driver, are responsible regardless of what the software does).

 

[2101Guy]

Maybe you shouldn't be putting your life in the hands of Tesla's beta-ware. Both FSD and AP are "beta" products and you must accept that disclosure when you enable those features. Don't be surprised if it kills you as it has others. My advice would be to stop using it for anything but adaptive cruise. The other features simply do not work and are not worth risking life and property (for which YOU, the driver, are responsible regardless of what the software does).

Enjoy

Tesla Autopilot safety almost 9x safer than average driving - Electrek.