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I can't wait for the next update! Phantom braking is driving me nuts.

Jul 29, 2020
69
36
San Francisco
We like many things about our model Y. But Not the autosteer or autopilot (TACC). Will try autopilot from time to time but still phantom braking does happen on the latest release.
There is no obvious pattern, except this: my wife is napping in the passenger seat, I'm driving on the freeway with autopilot, no cars nearby, the car suddenly and abruptly slows down even brakes suddenly.. She wakes up and says WHAT DID YOU DO? I answer defensively NOTHING THE CAR DID IT ON ITS OWN! And I proceed to turn Off autopilot. I guess it's something about the cameras, glare from the sun, reflections etc. Anyway no use in guessing why, it's Tesla issue to solve. .
 
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JimFeet

Supporting Member
Supporting Member
Aug 8, 2021
33
70
Moab, UT
Phantom braking makes Auto Pilot on our MY nearly unusable, especially in certain lighting conditions.

I live in Moab, UT, a red rock desert with wide open vistas and deep rock canyons. I often leave early in the morning and drive 250 miles of mostly wide well-striped 2-lane roads to Salt Lake City. In that distance we can experience upwards of more than 25 instances of phantom braking. In the dark, oncoming headlights as far away as 200 yards (really!) can initiate sudden violent braking dropping speed from 65 mph to 40 mph in less than 2 seconds. Other times approaching bridges or guardrails, oncoming trucks (usually dark colored) or sometimes absolutely nothing will cause an event. Most but by no means all braking events occur in poor lighting or with strong side light shadows.

I've endeavored to record many "bug reports" and have force-saved dash cam video but nothing out of the ordinary shows in later reviews. I've recalibrated the cameras with no effect. Here's my personal take on what could be behind phantom braking:

1. It would make sense for Tesla's AP to use the same object recognition algorithms as FSD. When dealing with self-driving, I'm sure Tesla is going to be ultra-conservative in their assessment; they don't want to be accused of causing collisions. Hence, braking is deemed preferable to incorrect analysis leading to a potentially fatal accident. (Although phantom braking can and likely will lead to rear end collisions.)

2. The forward looking cameras used for distance in our MY appear to be spaced no wider apart than human eyes, maybe less. In every other vehicle I've owned with "adaptive speed control" the traffic aware cameras have been spaced upwards of 10"-12" apart. This wider spacing offers far better distance/range analysis. Tesla is counting on their camera quality and range finding technology - but it's not there yet.

Anyway, neither of these conditions are likely to be resolved anytime soon so I end up driving my high tech automobile as if it was 1960.
 
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Fourdoor

Active Member
May 31, 2016
1,065
942
United States
Phantom braking makes Auto Pilot on our MY nearly unusable, especially in certain lighting conditions.

I live in Moab, UT, a red rock desert with wide open vistas and deep rock canyons. I often leave early in the morning and drive 250 miles of mostly wide well-striped 2-lane roads to Salt Lake City. In that distance we can experience upwards of more than 25 instances of phantom braking. In the dark, oncoming headlights as far away as 200 yards (really!) can initiate sudden violent braking dropping speed from 65 mph to 40 mph in less than 2 seconds. Other times approaching bridges or guardrails, oncoming trucks (usually dark colored) or sometimes absolutely nothing will cause an event. Most but by no means all braking events occur in poor lighting or with strong side light shadows.

I've endeavored to record many "bug reports" and have force-saved dash cam video but nothing out of the ordinary shows in later reviews. I've recalibrated the cameras with no effect. Here's my personal take on what could be behind phantom braking:

1. It would make sense for Tesla's AP to use the same object recognition algorithms as FSD. When dealing with self-driving, I'm sure Tesla is going to be ultra-conservative in their assessment; they don't want to be accused of causing collisions. Hence, braking is deemed preferable to incorrect analysis leading to a potentially fatal accident. (Although phantom braking can and likely will lead to rear end collisions.)

2. The forward looking cameras used for distance in our MY appear to be spaced no wider apart than human eyes, maybe less. In every other vehicle I've owned with "adaptive speed control" the traffic aware cameras have been spaced upwards of 10"-12" apart. This wider spacing offers far better distance/range analysis. Tesla is counting on their camera quality and range finding technology - but it's not there yet.

Anyway, neither of these conditions are likely to be resolved anytime soon so I end up driving my high tech automobile as if it was 1960.
I have a good solution as long as you will be traveling at one speed for the majority of the trip.


Keith
 

Valtor

Member
Aug 3, 2019
42
26
Becancour, QC
I am actually thinking of trading in my 2019 M3 for an older Model S with AP1 just to get rid of phantom braking. Would that be just a dumb move? Or can owners of AP1 models confirm that phantom braking is not as much an issue with AP1? I would be very happy with just dumb adaptive cruise at this point.
 

DoctaM3

Member
Dec 8, 2020
61
56
Pittsburgh
Honestly, it is one of the most annoying things about the car that I love otherwise. Phantom braking is totally random and I have not been able to put it together to figure out the case. Also new is "slowing for emergency vehicle" when there are no vehicles or lights in sight. REALLY painful. Anyone else getting these notices?
 
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growler23

Member
Apr 27, 2021
19
65
Austin, TX, USA
On the long road trip I recently took with TACC, there were many no-reason braking incidents, but I didn't notice any messages about emergency vehicles. I also tried to engage my problem-solving brain to figure out the causes of the braking, but there seemed to be no consistent thread. Sometimes no traffic nearby, no overpasses with shadows, sometimes there was traffic nearby... I really could not find a pattern before I turned it off and one-pedaled it the rest of the way.
I would accept "dumb" cruise control right now.
As has been pointed out, this used to work much better. I'm guessing we are caught in the wash of the massive merge of city and highway FSD code that apparently happened recently, and much was made worse for us highway drivers. I thought I would avoid a lot of this "bleeding edge of technology" pain by not choosing FSD, but apparently FSD's bleeding edge has caught up with me anyway.
I really hope this is worked out by the Spring - I am considering my next major road trip then. Somehow I am not buying Elon's current "so much better in 2 weeks" statements. I'm a software guy. Spring might be doable, but I am becoming convinced it won't be fixed by Christmas.
I know there is no marketing department, but does Tesla ever acknowledge problems like this? I like to believe they read these forums (I would if I were them) but it'd be good to know we are heard. And yes, I am pretty sure this is a problem a service center can't do a thing about.
 
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JimFeet

Supporting Member
Supporting Member
Aug 8, 2021
33
70
Moab, UT
On the long road trip I recently took with TACC, there were many no-reason braking incidents, but I didn't notice any messages about emergency vehicles. I also tried to engage my problem-solving brain to figure out the causes of the braking, but there seemed to be no consistent thread. Sometimes no traffic nearby, no overpasses with shadows, sometimes there was traffic nearby... I really could not find a pattern before I turned it off and one-pedaled it the rest of the way.
I would accept "dumb" cruise control right now.
As has been pointed out, this used to work much better. I'm guessing we are caught in the wash of the massive merge of city and highway FSD code that apparently happened recently, and much was made worse for us highway drivers. I thought I would avoid a lot of this "bleeding edge of technology" pain by not choosing FSD, but apparently FSD's bleeding edge has caught up with me anyway.
I really hope this is worked out by the Spring - I am considering my next major road trip then. Somehow I am not buying Elon's current "so much better in 2 weeks" statements. I'm a software guy. Spring might be doable, but I am becoming convinced it won't be fixed by Christmas.
I know there is no marketing department, but does Tesla ever acknowledge problems like this? I like to believe they read these forums (I would if I were them) but it'd be good to know we are heard. And yes, I am pretty sure this is a problem a service center can't do a thing about.
I agree completely. As a software developer myself I appreciate the complexities involved in dynamic real-time graphic analysis based solely on limited and variable video data. It seems unfortunate that Tesla apparently doesn't solicit owners' video and functional "black box" data (with the owner's explicit permission, of course) to serve as beta test information. I know you can create a "bug report" by making the verbal command, "bug report - phantom braking" which supposedly captures vehicle data, including video, for later download at your next service visit. But making a service visit appointment for phantom braking is useless.

NTSB has criticized Tesla for using the public for FSD beta testing but IMO it's the ONLY way to ensure software is capable of handling real world conditions and TACC is the best and safest foundation upon which to build FSD.
 
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JimFeet

Supporting Member
Supporting Member
Aug 8, 2021
33
70
Moab, UT
For those of you having issues, try recalibrating your cameras.
Have recalibrated multiple times without noticeable effect. Minimal phantom braking on interstates and whenever an "extra" lane such as passing lane is between an oncoming semi and me. Also, I often use TACC to help hold slow speed limits (25-30 mph) in town with no phantom braking evident. extreme phantom braking prevalent as previously described at 55mph or higher on wide, well-striped, two-lane highways with long range visibility.
 

mark95476

Active Member
Jun 21, 2020
1,938
1,490
Bay Area CA
I got some phantom braking using FSDbeta 10.3.1 last night.

1) A car was passing on the right and my Tesla braked hard which slowed me from from ~55 to 45 mph.
2) There was another coasting slow-down right as I was going through a clear intersection.
 

sckor

Member
May 1, 2015
25
3
Ottawa, Canada
I got some phantom braking using FSDbeta 10.3.1 last night.

1) A car was passing on the right and my Tesla braked hard which slowed me from from ~55 to 45 mph.
2) There was another coasting slow-down right as I was going through a clear intersection.
Curious - as a beta tester, are you able to provide feedback for events like this?
 

laservet

Member
Mar 9, 2020
387
256
Williamsburg, Virginia
Twice in my 20 mile drive to work today. Same old same old, nobody in my lane, overtaking a car in an adjacent lane that isn't moving toward my lane, 15 mph hard deceleration over 2-3 seconds, did not accelerate back up to speed in the 10-15 seconds I waited. It eventually would have picked up speed and overtaken the adjacent vehicle but by then I'd have been rear ended going so slow in the fast lane.
 

Valtor

Member
Aug 3, 2019
42
26
Becancour, QC
I just sold my 2019 Model 3 SR+ essentially because of phantom braking and am taking delivery of my new vehicule tomorrow morning. Adios phantom braking. At least I made a profit selling it higher than I paid 2 years ago.
 

PDX-Y

Member
May 24, 2021
189
222
Portland, OR
I'll chime in too. I did my first long road trip in a while today (to goose my Safety Score to 98, of course -- it worked), and the first since the update to 2021.32.22. It was great. Over 400 miles of driving, much of it in the PNW rain, and the car was rock solid. No significant comfort or safety issues at all, just normal gripes about lane selection (it really likes to get back to the right after passing even if I can see another slow car ahead, etc...).

Of course, I fully expect all that tuning to regress once Beta (hopefully! fingers crossed!) arrives, which is (I believe) running an older version of the highway stack and will be merging the highway and streets modes in an upcoming release.
 

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