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AP sudden braking with nothing in front

camrunr

Member
Nov 13, 2017
33
64
Camarillo, CA
Since the last few updates, AP is far smoother overall. Better lane keeping, better lane changes, better space management in traffic. But holy *sugar* that’s all down the drain when you get a panic stop at 70 mph out of nowhere and there’s traffic behind you.

This has happened with just radar assist on. Honestly, makes CC and AP nearly worthless. I really don’t want to be rear ended cuz AP thought it saw a ghost.
 

Tezlanian

Member
Apr 24, 2018
214
92
North America
Welcome to the beta program. I've had some decelerations going around curves with altitude changes but nothing like what you're describing. Can you try to reproduce it in the same place at a time with no traffic and take a video?
 

Tezlanian

Member
Apr 24, 2018
214
92
North America
I would notify Tesla so they can pull the info from your car and correct it.

What Tesla really needs are actual beta testers in the fleet and an interface to where we can log an event. Could even gamify it giving super charger credits or other stuff for legit reports. Or maybe that's stupid and it only appeals to me because I'm a tinkerer.
 

boaterva

Supporting Member
Supporting Member
Apr 2, 2016
7,573
3,746
Northern Virginia, USA
Since we’ve now been told that voice report actually works, I’d use that at the time of the incident (using the Note command mentioned in the Release Notes for the new Nav). That way they should get info about location to see if it was reacting to an overpass, etc. I’ve had this happen once or twice and need to remember to react quicker to make reports on the scene.
 
  • Informative
Reactions: modamoda

Tezlanian

Member
Apr 24, 2018
214
92
North America
Since we’ve now been told that voice report actually works, I’d use that at the time of the incident (using the Note command mentioned in the Release Notes for the new Nav). That way they should get info about location to see if it was reacting to an overpass, etc. I’ve had this happen once or twice and need to remember to react quicker to make reports on the scene.

Thanks for the info, I will definitely be using this!
 

AviP

Member
Feb 8, 2018
202
151
New Canaan, CT
Could be dirt/bugs on your sensors. Clean them up. False returns from reflective garbage by the side of the road. Who knows!?! Maybe a bug swarm in the middle of your lane. I've ridden my motorcycle through them and been instantly covered in bug splatter, all over my helmet windshield and shoulders. There's to many variables.

In the real world, be safe with BetaPilot.
 
Last edited:

camrunr

Member
Nov 13, 2017
33
64
Camarillo, CA
It’s happened 5 or 6 times. I’m sure the last 3 were passing under a bridge in bright daylight, so a sharp contrast is in play here. I was hoping the last update (2018.14.13) cured it, but no not so much. At least one time on a previous version was driving into an early morning sun, no bridge.

No dashcam, so no vid.

I’ll look into how to report it. Seems like an emergency brake, esp one that I override by mashing the accelerator, should either prompt to report or do it automatically.
 

fbitz777

Member
Apr 6, 2016
432
567
Wexford, PA
Could be dirt/bugs on your sensors. Clean them up and be safe with BetaPilot.

Since the last few updates, AP is far smoother overall. Better lane keeping, better lane changes, better space management in traffic. But holy *sugar* that’s all down the drain when you get a panic stop at 70 mph out of nowhere and there’s traffic behind you.

This has happened with just radar assist on. Honestly, makes CC and AP nearly worthless. I really don’t want to be rear ended cuz AP thought it saw a ghost.
Happened to me today although it did not feel like a panic...more like a sudden deceleration from 74 to 55mph...there was an underpass and I think these can trigger such a behaviour.
 
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Reactions: suwaneedad

irishndude4

Member
Feb 16, 2018
62
42
Pearland, TX
So I was going to post this comment last week, but I kept forgetting. I have not received my M3 yet but I met someone in Houston who has had one for about a month, and she mentioned a similar experience when using AutoPilot on the freeway going about 75 mph. She said she either tried to stop using autopilot or the car did this on its own, but the car immediately went from 75 to about 30mph and it scared the crap out of her. She said luckily nobody was behind her or else it probably would have caused an accident. When she told me this story, I thought she just did something wrong while driving and caused this herself, but sounds like maybe not? Pretty troubling to hear for those of making the leap very soon!
 

C141medic

Active Member
Apr 9, 2016
1,714
1,497
New Jersey
That’s scary stuff to read. Could this be an AEB issue rather than TACC since it’s reducing speed by at least 25mph? Just speculating.
 

barjohn

Member
Sep 23, 2017
547
668
Riverside, CA
I had it happen twice the other day and no overpass in either case and my car is pristine so no bugs or sensors covered with anything. I keep it super clean and clean it up when I get home and there was very little on the front. I had the same thing happen on my S on several occasions. The most recent episodes scared the sugar out of me because a big pickup truck was coming up fast on my tail and I neither wanted to be rear ended by him or have him think I was doing it on purpose and create a road rage situation where he would decide to run me off the road or worse. It does not give off the collision warning like a real almost collision does with its loud beeping. Instead it just suddenly slams on the brakes and when you are doing 75mph, even if it is just reducing your speed by 25mph it could definitely cause and accident. I hope Tesla is aware of the issue and trying to resolve it. Because all my travels are recorded by TeslaFi, I can provide the date, approximately where I was on the freeway and approximate time.
 

SlicedBr3ad

Member
Feb 25, 2017
922
828
Fl
Since we’ve now been told that voice report actually works, I’d use that at the time of the incident (using the Note command mentioned in the Release Notes for the new Nav). That way they should get info about location to see if it was reacting to an overpass, etc. I’ve had this happen once or twice and need to remember to react quicker to make reports on the scene.
What's the voice command to report it? Thanks!
 

SlicedBr3ad

Member
Feb 25, 2017
922
828
Fl
I had it happen twice the other day and no overpass in either case and my car is pristine so no bugs or sensors covered with anything. I keep it super clean and clean it up when I get home and there was very little on the front. I had the same thing happen on my S on several occasions. The most recent episodes scared the sugar out of me because a big pickup truck was coming up fast on my tail and I neither wanted to be rear ended by him or have him think I was doing it on purpose and create a road rage situation where he would decide to run me off the road or worse. It does not give off the collision warning like a real almost collision does with its loud beeping. Instead it just suddenly slams on the brakes and when you are doing 75mph, even if it is just reducing your speed by 25mph it could definitely cause and accident. I hope Tesla is aware of the issue and trying to resolve it. Because all my travels are recorded by TeslaFi, I can provide the date, approximately where I was on the freeway and approximate time.
Is it safe to sign up to teslafi?
 

Sawyer8888

Member
Mar 16, 2017
422
421
South Florida
I've noticed unintended decelerations when traveling on slight bends in the road. AP sometimes thinks the vehicle further ahead in the adjacent lane is in my lane. These are not massive slow-downs. Perhaps they only 10 mph swings. Still, very uncomfortable often requiring a quick flooring of the accelerator, and occasionally an expletive.
 

barjohn

Member
Sep 23, 2017
547
668
Riverside, CA
I think it is safe to use TeslaFi. However, I also use Remote S and Key for Tesla along with a couple of other apps. It would be nice if they would allow token log in and all of them say they don't keep a copy of your user name and password that these are just handed off encrypted to the Tesla Server and they then operate off a token. There is some trust required and until I have reason to believe that it shouldn't be given I will continue to give that trust. I do change the password from time to time but it is a hassle to then go fix all the programs that breaks.
 
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Reactions: SlicedBr3ad

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