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Automatic emergency braking

Discussion in 'Model X: Driving Dynamics' started by NoVIN4Me, Apr 27, 2016.

  1. NoVIN4Me

    NoVIN4Me Member

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    My car is current default to off for emergency braking. Should I enable it all the time?
     
  2. Aljohn

    Aljohn Member

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    I would think so... It has no affect on driving, unless you need it.
     
  3. thimel

    thimel Member

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    Unless the X is different than the S, you cannot do that. You can default the warning sound to off, but AEB automatically reenables each time you start the car.
     
  4. NoVIN4Me

    NoVIN4Me Member

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    I see. Let me double check! Thanks.
     
  5. dwebb66

    dwebb66 Member

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    Why would you want to disable it??
     
  6. aesculus

    aesculus Still Trying to Figure this All Out

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    The other day we were passing a semi with a full box and it had one of those 5th wheel bases in tow behind the truck. The Model X went ballistic and thought it was going to be attacked. I quickly jerked into the left lane and it released its death grip on the brakes.
     
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  7. NoVIN4Me

    NoVIN4Me Member

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    Does the AEB take into account the car distance behind you? I did check that mine is enabled after all.
     
  8. Scrith

    Scrith Member

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    #8 Scrith, Jun 6, 2016
    Last edited: Jun 6, 2016
    I have had a scary experience a couple of times in my first 1500 miles with the X (my first Tesla, third electric vehicle) and am wondering if it is some kind of hidden feature of the emergency braking system: a car quite a ways in front of me suddenly stops for some reason, so I hit the brakes rather hard myself (even though there is quite a bit of room between him and I) as a precaution...but the Tesla doesn't slow much at all. I start getting worried as I quickly approach this stopped (or soon to be stopped) car in front of me and really begin hitting the brakes hard, but the Tesla is taking a rather leisurely pace at slowing down. I panic and hit the brakes as hard as I can as I approach the car in front, hear some warning chimes as I begin thinking I'm going to hit this vehicle, and then emergency braking kicks in and I stop just in time.

    Is the car trying to give me a heart attack, ignoring my hard braking because it doesn't detect an imminent collision, or is something broken? I'm tempted to try looking for an empty stretch of road and try just stomping the brake pedal as hard as I can to see if it will let me brake hard for no reason at all, as a test. Keep in mind autopilot was OFF in both situations (I didn't purchase it, and haven't upgraded to it yet). I haven't changed any emergency braking settings since picking up the car, so I assume they are set to default values.
     
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  9. Discoducky

    Discoducky Active Member

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    It does not as it does not have an appropriate sensor that works at a great enough distance at a high enough speed. Ultrasonics are not sufficient for mitigating large amounts of crash energy. You'd need something more robust like radar, red-shift vision or lidar to mitigate at speed.
     
  10. xkwizit

    xkwizit Member

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    @Scrith - if you hit the brakes yourself the AEB will not come into play. It does not override a user action. If you are using TACC, the car will take action to slow down and lessen the impact. It may not always be able to avoid a collision. However, the moment you press the brakes, TACC is off and so is AEB.
     
  11. Scrith

    Scrith Member

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    Following up on my post about poor braking at high speeds, I tested it on a long, straight, empty straightaway today and experienced something very similar: from 65 to 30 (or so) the braking is quite slow, perhaps due to the weight of the vehicle, then it grabs quite hard for a sudden stop. This seems dangerous...has anyone else noticed this problem (or not noticed it) when trying a sudden stop from high speed?

    I guess my expectations are based on my last two vehicles, a 2013 LEAF and a 2004 BMW 330i ZHP, both of which seemed to be significantly more responsive during hard braking at high speeds.
     
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  12. goneskiian

    goneskiian Active Member

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    I wonder if this has anything to do with the brakes not being bedded in quite yet. Try doing this a half dozen times and see if it changes at all.
     
  13. Hengist

    Hengist Member

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    I would have SC check brake system. Model S brakes are very effective at speed, Model X is supposed to be similar. Car weight is not terribly different.
     

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