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PSA: CAREFUL--Autopilot sudden braking

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Just heard back via email (see below). hopefully speak to them today. I haven’t use autopilot in a while so I will not be helpful in diagnosing the problem since it won’t show in the logs. Anybody that has had it happen recently should write Tesla via your account so they can see the logs

Thank you for writing in! I have not heard about this issue occurring particularly after this firmware update. Sometimes, the vehicle decelerates when it detects an overpass. I am not sure if that is the case but I reached out to our Vehicle Support team and they will call you to investigate further. They have expertise and better tools when it comes to troubleshooting. Please feel free to reach out to me if you do not receive any call from them today. Have a great day!
Best Regards,

Executive Care
Ok. Executive care called. They are highly interested in collecting more data on this issue and are encouraging customers who have experienced this issue to report it (with exact time and circumstances) so they can pull the logs. I obviously could not help since it has been a while since I have used autopilot.

Another way they suggested that we report it is to use the voice control and say “bug report” and identify “autopilot”. That apparently time stamps it so they can pull the logs. But it would be good to call it in as well as since they would like context as well of what was going on when it happened.

So again, please contribute to solving this issue by noting when it happened and reporting it via the voice control or filing it via the report to management.
 
Is this happening with TACC only or with both TACC and autosteer engaged?

It can happen in either scenario. I've had it happen in both situations. In my case, it was more of a gentle brake, but definitely as I was approaching an overpass.

Also, on a local road where I was on TACC only, there was a section with lots of tree shadows. The car kept braking and going and braking and going. No one was behind me, so I let it do its thing just to observe.
 
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Subject: Bug report. - autopilot sudden braking [ ref:_00D506dxX._500f1g1RWo:ref ]

Hello Ryan,

Thank you for writing in! I am sorry to know about the sudden braking and apologize for the inconvenience. Sometimes, vehicle decelerate when it detects the overpass. I am not sure if that is the case however, I have forwarded your feedback to our Engineering team. We are always striving to improve our products and feedback such as yours is highly valued! Please reach out to our Technical Support team at 877-798-3752 with details like timestamps, location, car speed etc, in case the issue occurs frequently . They can pull the logs and contact diagnostic support team.
Rest assured, safety of the customers is our number one priority and we work diligently on improving our autopilot functionality. thank you for being Tesla Owner!
Best Regards,
Trupti S | Executive Care
45500 Fremont Blvd | Fremont, CA 94538
 
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Hey all, I just joined this site to find out if others have experienced this issue. This has happened to me about six or seven times since getting my Model 3 in March. My husband has the Model S and has never had this problem. It is scary and I can’t figure out a pattern except it’s usually within the first 15 minutes of engaging autopilot Always during the day but that’s when I typically drive. No cars in front of me and haven’t noticed shadows but will look out for that.
 
Had this happen to me for the first time yesterday on a long drive back from Cape Cod. Both times autopilot decided to slow down suddenly was when I was about to go under an overpass and both happened within just 2 or 3 minutes of each other. I’m on 2018.18.13 (as I’m sure just about everyone else here is on), so this is definitely still an issue with the latest software.
 
I know there are other threads about this. But I think it is serious enough flaw in AP, that I think everybody should be careful (Trust me, I am not a short seller. I own 3 Teslas).

Situation: When autopilot is engaged, it somehow sees some shadows/images, and it brakes pretty hard even though no car is in front of you. It does not come to complete stop, but it will go from 65-70 to 45 pretty quickly.

Conditions: Typically for me it has been driving in the dark (evening or early morning) and going under an underpass. I am not sure if others have seen this during the daytime or other conditions.

Please take notice of this and be careful when engaging autopilot. I have already been rear-ended (not related to this issue), but I can see how this bug can create a hazardous situation where somebody behind could rear end you.

I hope Tesla takes note of this and fixes it soon....it can be fairly dangerous. In the meantime, I have taken to driving again without autopilot until the next update.
When I’m on autopilot I always keep my foot on the « gas pedal », precisely for this reason. With that you can usually override phantom breaking very quickly. My right foot gets pretty tired :(

In one ocurrence, I had my right foot loose (far from the pedals) and it was actually pretty messy. I rushed for the accelerator and pressed the brakes by mistake. It was a light press so it actually disengaged autopilot and stopped braking but it was not very good.

Another trick... I don’t use autopilot when someone is tailgating or move over. Also be careful when large vehicles are following you.

This bug is seriously annoying. The bulk of autopilot accident coverage focuses only on stationary objects. Trust me phantom breaking is a lot more frequent on the freeways than stationary objects (and unlike stationary objects paying attention doesn’t necessarily prevent accidents).
 
I would add: I wish Tesla paid less attention to solving the stationary object problem and more attention to this. Bottom line if you use autopilot as designed (on the highway) stationary objects are not all that common and you don’t have to be extremely focused to handle them.

So far all the instances of stationary objects collision I have seen are with people who were not paying attention at all to the road, doing something else.

I suspect that this phantom braking issue is the result of Tesla trying to address these collisions with stationary objects. They try to overcome the limitation of radar and that results in too many false positives.
 
Reporting the issue is enough of a drag to make drivers skip it.

Why does the driver need to be involved anyway?

I think the next AP update needs to include Groundhog Mode*, where the system auto-reports any events that surround any high speed braking manoeuvers that it initiates.

*I saw a shadow and braked myself.
 
There's a very curvy road near my home. It's a 25 mph zone and it's hard for me (psychologically) to drive that slow, so I use TACC. Often the Model 3 will detect a car approaching in the other lane, or a parked car in the parking lane, as being in front of me and will brake. The first time it happened I disengaged TACC. Now I just use the go pedal to maintain speed.

I imagine this is an entirely different issue than what others are talking about here, but I can see it being significant if using TACC on curvy mountain roads at highway speed.
 
I just experienced my first sudden braking on the highway with a car behind me, thankfully my instincts and reflexes were quick enough to prevent an accident. I'd advise everyone to keep their foot on the pedals when going highway speeds just in case.
 
Ok. Executive care called. They are highly interested in collecting more data on this issue and are encouraging customers who have experienced this issue to report it (with exact time and circumstances) so they can pull the logs. I obviously could not help since it has been a while since I have used autopilot.

Another way they suggested that we report it is to use the voice control and say “bug report” and identify “autopilot”. That apparently time stamps it so they can pull the logs. But it would be good to call it in as well as since they would like context as well of what was going on when it happened.

So again, please contribute to solving this issue by noting when it happened and reporting it via the voice control or filing it via the report to management.
Can you send them a link to this thread?
 
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Took my car into the service center for unrelated last week and this happened for the 4th time on my way in. I explained and gave them the exact time it happened. Suggesting this only started happening in the last 2 updates the service advisor stated that he doubted it was firmware and decided to align/calibrate the radar.... I don't have the car back but I'm not sure why we would all be having this issue if it were truly a hardware issue.
 
Can you send them a link to this thread?
They know it is a problem...they just need data to debug. Coming to this thread does nothing but validate the issue which they acknowledge. So ultimately it is up to us to supply the data by reporting it and giving them logs to work with to debug. So stop reporting it to this thread....report it to Tesla.

Telling fellow owners that there is an issue does nothing at this point.
 
Took my car into the service center for unrelated last week and this happened for the 4th time on my way in. I explained and gave them the exact time it happened. Suggesting this only started happening in the last 2 updates the service advisor stated that he doubted it was firmware and decided to align/calibrate the radar.... I don't have the car back but I'm not sure why we would all be having this issue if it were truly a hardware issue.
Yeah I am sure it is a separate group who is dealing with this and service centers are unaware(as with most software issues). The person I spoke to was on a dedicated team working on these autopilot issues.
 
Since it happened, I have stopped using AP when my family is riding with me. When I do use it at high speed, I have my foot very close to the accelerator pedal. Definitely will report if it happens again.