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Well there’s a thing, sudden unintended acceleration just happened to me

Discussion in 'Model 3' started by Marc Roberts, Jun 27, 2020.

  1. Marc Roberts

    Marc Roberts Member

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    So I know what responses this is going to get, because I have made the same responses. I’m going to send my experience as follows to Tesla and try to reproduce in a safe environment.

    I was driving forward into a parking space, on the flat, feathering the accelerator to creep forward (I use hold mode). As I lifted my foot *off* of the accelerator the car lurched forward. Luckily I was quick on the brakes and I didn’t crash into anything. Chill mode might also have saved my front bumper...

    Like I say, I firmly expect to receive a load of responses calling BS, but I’m just reporting my experience. It feels as though the car got confused by low speed where the “hold” action kicks in and the feathering of the pedal. It was enough for my wife to have a go at me about it.
     
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  2. goldengate

    goldengate Member

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    I would take the vehicle into service immediately and have them pull the logs and examine the car.
     
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  3. 1.21GW

    1.21GW Member

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    I would echo that. Get it to a service center.
     
  4. Marc Roberts

    Marc Roberts Member

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    I have mobile service booked for a couple of weeks time, do you think they'll be able to look at the logs?
     
  5. LACALawyer

    LACALawyer Banned

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    Am I the only one who now watches out for this each and every time despite it never happening to me?
     
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  6. LACALawyer

    LACALawyer Banned

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    call the local news. I guarantee Tesla will come over in 1 hour instead of 2 weeks...
     
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  7. Marc Roberts

    Marc Roberts Member

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    I've been really skeptical about every report I've seen about it, but if I hadn't been quick on the brakes, I'd have crashed into the big sign displaying the prices at the local fuel station, and then I *would* have been one of those news stories.

    And because I *was* feathering the accelerator, I bet the public response would be that the logs show that the accelerator was being pressed when the acceleration happened...
     
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  8. Stickboy46

    Stickboy46 Member

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    Question. Did it actually accelerate? Or did the regenerative braking not kick in. I've had the same scenario but instead of it acclerating it just felt like the regen braking just never triggered causing me to continue at my current speed when i was expecting to slow down. It was always in a parking lot too, so low speeds.
     
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  9. Marc Roberts

    Marc Roberts Member

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    This is a really fair question, and I know it's hard to take a random person's word for it, but as it was on the flat (as opposed to downhill), I am positive it accelerated rather than "not regen".

    But, I'm going to try and find any empty space to try things out, see if I can get steps to reproduce.
     
  10. Eriamjh1138

    Eriamjh1138 Member

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    It never happens to a lot of people. Being mentally aware of it may save you from an incident.

    This is the first report where the driver reported he went to the brakes to stop it.

    This is not pedal Mis-application.
     
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  11. p010sp0rt8

    p010sp0rt8 Member

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    I can 70% reproduce a test case where the car “unintentionally” accelerated coming into my driveway.

    I’ve actually chalked it up to an oddity in regenerative breaking.

    My street slopes down to my driveway and my driveway slopes up causing a relatively small “v”. Angles to the normal eye are not extreme. If I turn to get into my driveway at a faster than normal speed I let off the accelerator as the car is approaching the lowest part of the V to not scrape. My expectation is for the regen braking to kick in and slow the car. It does not.
    Instead the car will continue as if regen braking is not active and the car will continue at its now higher momentum due to the decline. This is alarming and feels like unexpected acceleration since I’m used to regen braking taking over.

    regen mode on high
    Drive mode in sport
    Often times I’m also pressing the button for homelink and turning the wheel at the same time
     
  12. DS369

    DS369 Member

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    I bet that it has something to do with mechanical part of the pedal and car reading it's position. I have a good gut feeling about it. The "feathering" part is the key. I bet the car reading the accelerator position values gets some kind of a error, array overflow or something. I will try to experiment on my M3 with it. Also I feel like the pedal system slowing getting worn out and causing lack of smoothness of operation to impact the experience. For example I can hear the breaking pedal actuation sometimes, kind of a creak. This physical wear causes the car computer to get values from the sensor that are breaking the logic.
     
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  13. MasterC17

    MasterC17 Member

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    Have you checked your floor mat to ensure it is properly secured and not interfering with the operation of the accelerator pedal?
     
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  14. dykdyk

    dykdyk Member

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    The very reason I stopped using the “Chill” mode is the gut sensation at certain speeds that the regen breaking is also, somehow in chill mode in a certain band of speeds closer to 5-12mph. Feels like certain combinations of conditions make it seem as if a car accelerating. That’s an uneasy out of control feeling.
     
  15. Electric Dream

    Electric Dream Pilots the Millennium Milkfloat

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    The accelerator pedal has two sensors and their outputs are cross-referenced, so your explanation isn't possible.
    There hasn't been one case I'm aware of where a Tesla's 'unintended acceleration' was due to a sensor fault.
    There was an issue with the software when hold mode first came which caused unexpected behaviour (not unintended accleration) but that was addressed pretty quickly.

    The Model 3 is a heavy car with very little frictional loss in the drivetrain. Try putting it into neutral at 10mph in a parking lot and see how that feels. It's got a lot of momentum and hardy any friction to slow it down. To some people it feels like the car is accelerating. I'm not saying that's the cause in this case, but lack of regen could be it or some other combination of conditions, driving settings, car status etc.
     
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  16. mtndrew1

    mtndrew1 Active Member

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    I’ve got a dollar on bumping the drive/autopilot stalk unintentionally and initiating TACC. When tooling around the cruise will set at 18 MPH or so and there’s no confirmation chime for cruise.
     
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  17. camalaio

    camalaio Active Member

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    I keep saying it. I'll say it again. The Hold stop mode has some odd behaviour at low speeds, and sometimes accelerates unexpectedly (and sometimes in an unexpected direction!).

    Was there a small dip or hole in the road surface at all? Or a raised bit?
     
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  18. M109Rider

    M109Rider Active Member

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    OMG. gotta love lawyers.
    There are ways to “Investigate this” Before bringing in the media to damage their reputation.
     
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  19. Electric Dream

    Electric Dream Pilots the Millennium Milkfloat

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    Or just shifted into neutral rather than drive or reverse, so hold mode didn't actually stop the car from rolling...
     
  20. M109Rider

    M109Rider Active Member

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    That’s my bet also. He seems confident this isn’t the case though, so who knows.
     

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