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Model S Slid Away...

Discussion in 'Model S' started by Dgogs, Feb 19, 2021.

  1. 46&2

    46&2 Member

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    For all the people who haven't seen the linked video and can't believe what happened, click on the Twitter link posted by @Art_Vandelay which shows this perfectly: The car slides with the parking brake fully locked. Front axle is free to roll:

     
  2. David.85D

    David.85D Active Member

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    why the thumbs down? This is exactly what the manual says. And it also says not to park on icy hills and the driver is responsible to evaluate conditions.
     
    • Like x 1
  3. David29

    David29 Supporting Member

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    Not sure about your Model S, but the manual for mine says the parking brake is engaged automatically when you put the car into Park. It says nothing that I can see about needing to press the brake pedal for three seconds:

    "Parking Brake
    "The parking brake automatically engages when you shift Model S into Park, and releases
    when you shift into any other gear. Note: The parking brake operates on the rear
    wheels only, and is independent of the pedal operated brake system.
    "Warning: In snowy or icy conditions the rear wheels may not have sufficient
    traction to prevent Model S from sliding down a slope, particularly if not using
    winter tires. Avoid parking on hills in snowy or icy conditions. You are always
    responsible for parking safely.
    "Warning: Your Model S may display an alert if the road is too steep to safely park
    on, or if the parking brakes are not properly engaged. These alerts are for
    guidance purposes only and are not a substitute for the driver’s judgment of
    safe parking conditions, including specific road or weather conditions. Do not
    depend on these alerts to determine whether or not it is safe to park at any
    location. ..."
    The manual does mention the red parking brake symbol when you manually apply the parking brakes, and says that reversing that action (releasing the parking brakes) also puts the car into neutral. But I still see no mention of three seconds.
     
  4. speedy

    speedy Member

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    In the Massachusetts area, your best bet for Tesla repair is Todays Collision in Malden. Bobby will take care of you. They love Teslas, are Tesla approved, and do a great job.
     
  5. David.85D

    David.85D Active Member

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    second sentence… “Pressing and holding…”. On my car, that’s the only way to get the red park icon. And I hear some actuator when I do this, so something mechanical is happening.
     

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  6. Dgogs

    Dgogs Member

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    Thank you everyone for any and all information that you were able to provide. I took my car to a Tesla certified body shop yesterday and they have already gotten the ball rolling on ordering parts for the repairs. Based on the manager's original assessment of the damage the "unofficial" quote to repair is around $20K. Thankfully insurance has been great with this so far and they are covering everything as expected but did not put me at fault (I assume if Sentry mode was not recording this would not be the case.)

    I have attached a link to the damage caused by this for anyone that is interested.

    https://photos.app.goo.gl/UEKDUu1AJPgM3hGf6
     
    • Informative x 3
  7. BrokerDon

    BrokerDon Active Member

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    Hmmm...

    Why not park your Tesla in your garage which is flat and not icy instead of on a fairly steep icy driveway? :confused:
     
  8. MorrisonHiker

    MorrisonHiker S 100D 2021.4.11

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    Does that quote also include replacing or repairing the wall connector?
     
  9. David29

    David29 Supporting Member

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    #69 David29, Feb 24, 2021
    Last edited: Feb 24, 2021
    Interesting. The language in my latest manual is definitely different. I wonder if that has to do with my car, or maybe I do not have the latest manual. The version I use was downloaded in November 2019.

    I went to the Tesla "Account" page and downloaded the current version of the manual, which has different language, the language you posted. Very interesting! I wonder if the function changed, maybe via software. Or if later cars are different?
    What would manually applying the parking brake do, if the car is in Park already, which automatically engages the parking brakes anyway? Confused about that....
     
    • Informative x 1
  10. David.85D

    David.85D Active Member

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    The photo i posted shows the manual viewable on the MCU. I assume that is the most recent version. I don’t know either.

    Definitely hear the actuator doing something when the car is in park and I do the long hold of the park button to get the red parking brake icon.
     
  11. jordanX

    jordanX Member

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    Before I took delivery I cleaned out the garage for my MX! If I were lucky to win the lottery I would get the new MX but first would have to clean the other half of the garage!
    If I couldn't have a garage knowing now that sliding is possible, I would purchase some heat trak mats and park on them. (heattrak.com) They come in a variety of sizes for home and business. I just purchased a 40x60" mat for my uncovered front porch and put the smaller one on the back deck. These mats will keep snow from building up at a rate of about 3 inches an hour. Heattrak says 2 inches/hr but my experience is about 3'/hr. I love not shoveling my front porch or worrying someone might slip. The mat on the back deck allows me to step outside, close the door and start shoveling.
    My only complaints are they only last about 4-5 years (about a dozen years I've used them) and the cost. I wish Costco would carry the porch mats again as they were much cheaper. The one I received Friday looks like a redesign that will last longer; the sale they just had got me to pull the trigger especially since I am now the chief (only) snow remover in the family. About 3 years ago I purchased a couple of mats from a supposedly competitor that was cheaper but quickly regretted it. Lousy quality, poor heating, not that much cheaper, didn't look as nice.... NO comparison. I have a wifi cord so you can turn it on or off but have not connected it. Electric consumption has not been an issue. I have the big mat on now and my whole house is currently only using 0.7kW according to my Tesla solar app! With the driveway mats I would use the wifi cord and app.
     
  12. MikeHolliday

    MikeHolliday Member

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    It is not confusing, when you stop the car and press the stalk button once it is essentially the same as putting an ICE car into Park with the Gear selector, Pressing and holding for the 3 seconds applies the parking BRAKE...
     
  13. David.85D

    David.85D Active Member

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    Automatic transmission ICE cars have a parking pawl (gear) that engages when in park, keeping the engine and transmission from rotating. From what I’ve read, there is no such feature in Tesla drive units. They could hold the motor stationary with an applied field, but that would consume energy. Don’t know…. It’s not a clear parallel…
     
  14. MikeHolliday

    MikeHolliday Member

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    No it would not consume energy, except briefly when applied or disengaged.... And yes, they are 2 separate braking systems. Ask your Service Center...
     
  15. ucmndd

    ucmndd Well-Known Member

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    The long hold on the park button is indeed a sort of “extra” parking brake - basically increased force on the rotors over the regular park setting for hills or other situations where it’s warranted.

    Not that it would have made the tiniest difference in this case. OP could have literally bolted the wheels to the rotors and the car still would have slid. Parking on ice with non-winter tires will do that.
     
    • Like x 1
  16. Enginerd

    Enginerd Member

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    Here's my theory: there isn't much difference between neutral and park. I think:
    • Park: Traction motor(s) de-energized. Electric rear brake caliper engaged. Must press brake pedal to shift into D or R, which also releases electric rear brake.
    • Neutral: Traction motor(s) de-energized. Electric rear brake caliper disengaged. No need to press brake pedal to shift into D or R.
    Either way, whether you are simply in Park or have the press-and-hold Parking brake engaged, the only thing holding you in place is the electric rear brake, with no transmission parking pawl (or electric traction motor equivalent). If this is all true, the only benefit of the red ((P)) warning indication on screen is confirmation that you've engaged the electric rear brake, which might be useful to know if you accidentally do it while driving.

    The schematic posted by @dmurphy suggests the electric rear brake is binary: engaged or not... without a variable level of clamping force.
     
  17. ucmndd

    ucmndd Well-Known Member

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    The experiment I just carried out in my driveway suggests otherwise. In this video I cycle to drive, then park, then long-press park. You can very clearly hear the parking brake motor at each step.

     
    • Like x 1
  18. Ofarlig

    Ofarlig Member

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    The parking break does get applied when pressing park (driving in salty winter conditions will make it stick overnight), not sure if it is instantly after going into park though.

    Pressing and holding is used for emergency braking so that should be instantly.
     
  19. dmurphy

    dmurphy Woof.

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    Right. That extra whir/click you hear when doing the long press is the actuator on the parking brake motor. No matter current state, when you long press, the motor actuates to ensure engagement. It’s a short whir/click because there’s no travel left, but it’s trying anyway.

    Because it’s used in an emergency, there’s no software saying “parking brake already engaged; ignoring button press.” It’s simply “button pressed so I’m extending.”

    My natural gas fireplace does the same thing - if I hit the “off” button when it’s already off, you can hear the valve engage and click - it’s trying to close even when fully closed. Safety item.
     
    • Like x 1
  20. whitex

    whitex Well-Known Member

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    #80 whitex, Feb 25, 2021
    Last edited: Feb 25, 2021
    @Dgogs , normal seen-before behavior - there is nothing wrong with your car (except any damage from charging cable being pulled out hard).
    This happened to me before, here is a thread with the video of the incident:
    Hill-hold releases *after* you get out of the car?
    You can clearly see the front wheels starting to roll when the car locks, while the back wheels are on ice and cannot hold the car on a not very steep driveway. Either hill hold releases when locking, or air suspension releveled causing just enough disturbance to break the static friction. I am partial to the theory of hill hold releasing when car locks and shuts down.
     

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