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Putting the car in Park while driving

Discussion in 'Model S: Driving Dynamics' started by austinEV, Jul 7, 2014.

  1. austinEV

    austinEV Active Member

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    After about 9 months in my Model S, this might be the last question I really have. What exactly happens if I am driving 60 mph and push the button on the stalk to put it in park? I like to think it is disabled if the car is in motion, but I did an experiment going maybe 5mph and yep it slammed on brakes stopping with a lurch.

    I ask, because the button to squirt the washer fluid is... a button on the end of a stalk, just on the left side. Every time I wash my windows I feel like I am risking my life if that is the day I get it scrambled. Can anyone confirm it has a safety interlock to prevent the parking brakes from engaging at speed? I seem to recall some people saying that is a feature, since it is similar to engaging a parking brake or handbrake.
     
  2. David99

    David99 Active Member

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    It's not dramatic. The parking brakes are the smaller brake calipers you can see on the back wheel. If you put it in P while driving the car will slow down and come to a stop at about the same speed as if you pull a traditional hand brake (or e-brake). It's not going to break anything on your car. It is supposed to be an emergency brake that works separate of the main brake system. If regen fails and the main brake fails this is the way to slow down and stop your car from any speed you are going.
     
  3. austinEV

    austinEV Active Member

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    I guess I should try it then in a controlled situation. Still the accidental application of these would be jarring at best.
     
  4. shelbri

    shelbri Member

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    I asked the same question during my test drive and was told that it would remain engaged up to 7-8mph but above that it would not so anything. You cannot shift to park above those speeds. This is only based on the response from my Tesla store manager during the test drive.
     
  5. stevezzzz

    stevezzzz R;SigS;P85D;SigX

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    You got some bad info, or at least some incomplete info. If you stab at the silver button on the end of the transmission stalk and release it, at very low speeds the car goes into Park and stops with a lurch. At higher speeds (the threshold speed is unknown to me), a momentary press on the button won't do anything: you have to press and hold the button to engage the emergency brake, which actuates the same mechanism that is used for Park.
     
  6. wk057

    wk057 Senior Tinkerer

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    I plan to test this one of these days...
     
  7. Liz G

    Liz G P03056

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    The car will beep at you quite loudly if you attempt to put the car in park while driving.

    I've done this a couple of times when trying to hit the windshield wipers. The stalk button for triggering the wipers in my old car is in the exact same spot as Park on the Model S.

    Did not notice any deceleration (or should I say negative acceleration) but then the beep startled me and I quickly would stop depressing the button.
     
  8. woof

    woof Model S #P683 Blue 85 kWh

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    Either press and hold the silver end of the stalk, or touch and hold the big red "EMERGENCY BRAKE" tap area on the "E-Brake and Power Off" controls screen. I've done that during an advanced driving class in an attempt to get the rear wheels to break free during a turn so I could learn how to correct for it...didn't work BTW.

    But you must HOLD it down in order to keep the brake engaged.
     
  9. pete8314

    pete8314 Vendor

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    Interesting thread...I wonder if the brake lights illuminate when the parking/e-Brake is engaged when in motion....if not, might be a bit of a shock for the guy behind.
     
  10. tezco

    tezco Sig P85

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    This works exactly as described in previous version of the owners manual. If the hydraulic brakes fail, you use the button on the stalk to modulate the emergency brake. I can't find this in the current version of the owners manual; however.
     
  11. austinEV

    austinEV Active Member

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    I suppose the next logical question is " What happens if you shift into reverse at 60mph?" That one should really be "nothing" since there is no good that can come of it. That one I don't feel like testing...
     
  12. mkuendig

    mkuendig Member

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    it says in the controls, park that you can use it as emergency brakes. I find this strange as it applies the brakes only to the rear tires.

    we tried this once on a race track with 50 mph. the car started to rotate immediately on a slippery track. with the normal brakes the car could be controlled/steered because of abs.

    so my learning, don't use this. it engages much slower than normal brakes. but as somebody wrote above, use it when the normal brakes fail.
     
  13. caddieo

    caddieo Member

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    You would lurch or come to a jarring stop at slow speeds since the parking brakes have less momentum/speed to overcome. At higher speeds the effect would be more gradual as described by others in the thread.
     
  14. NigelM

    NigelM Recovering Member

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    You can test it. The car beeps and a dash warning tells you something like "that operation is not possible".
     
  15. yobigd20

    yobigd20 Well-Known Member

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    I've accidentally done this once at high speeds for the very same reason. I have no idea why I pushed the right stalk button in and held it instead of the left one. In my head I was putting the windsheild wipers on but I totally f*'d up and hit the right stalk. The car *DOES NOT* come to a screeching halt. After a second when it engages it simply starts to slow down gracefully. That is it. Nothing drastic, so don't worry about it. The part that I find irritating is that it takes a second or so to engage. So if it were a true emergency well sorry its not going to stop you fast enough. In a situation where every stopping second counts, I would much rather have a dedicated parking brake handle or button somewhere where it will engage immediately as soon as you press it that would in fact be a very strong stop. I'm not sure what safety standards specify in a situation where you have to engage the "parking/emergency" brake but I was disappointed with the slow response and it enlightened me that I really can't count on that stopping me in the same manner of slamming the brakes on. I guess there's a difference between "emergency brake" and "parking brake" because this is clearly a "parking break" and not an "emergency brake". Good thing we have regen and we dont use our brake pads very often so hopefully I'll never have an instance were I would need to engage a secondary emergency brake.

    I guess what I'm comparing / referencing it to was an emergency brake handle in my old `97 camaro. If you yank that as hard as possible the car would stop pretty fast and the response was immediate. You don't have that emergency brake in the Model S. I actually did need that once in the camaro too where I was in the Poconos Mountains in the middle of a massive snow storm in the middle of the night with no roads plowed at all and the master brake cylinder blew and I had 00000000 brakes. Smashing the brake pedal did absolutely NOTHING. fortunately, I was literally the only idiot on the roads in that storm and I continued on the highway for another 40 miles or so driving at 20-25mph. this was before I had a cell phone too so I didnt really have a choice other than to keep going. I had to use the emergency brake to slow down during the exits ramps and around a windy road to get to my vk house. I don't think I'd be able to do the same with the Model S parking brake.
     
  16. tezco

    tezco Sig P85

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    The Leaf also uses an electric parking brake which doubles as an emergency brake. If memory serves me correct, you press once for mild braking, and twice if more breaking force is required.

    Modern cars are much less likely to lose their hydraulic brakes due to dual reservoirs and isolated circuits that were mandated many years ago. I blew a brake hose in my old Dodge and rear ended a Pinto full of illegals that had slammed on their brakes in the middle of the street for no apparent reason. Fortunately their gas tank didn't rupture. Tiny dent on my bumper; totaled Pinto though...

    The week before a 5 year old rode her bike out between two parked cars. I slammed on the brakes and she disappeared under the fender in front of the passenger side front tire. I closed my eyes, preparing for the bump which would mean that I'd run over her torso, but it never came as the car stopped with an inch to spare. Thank goodness for cars that rode high off the ground, and I guess there was a saint looking after that little girl, a saint who held that brake hose together for another week.
     
  17. islandbayy

    islandbayy Active Member

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    You cant. Highest speed you can change directions is 5mph. Above that, nothing, but might shift to neutral. As their is no transmission, you can switch from F to R and R to F without coming to a complete stop.
    It's actually called "Plug Braking" as it will use the motors power if you apply the accelerator to bring you to a stop and reverse direction.
     
  18. mgboyes

    mgboyes Member

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    It's a documented emergency feature - my DS mentioned it when handing over the car.

    If you push briefly (at significant speed) it will warn you and do nothing.
    If you push and hold it will engage the parking brake (which takes a couple of seconds to have an effect as it's a screw drive motor that brings the parking pads into contact with the discs).
    The point of having this is so that if the hydraulic system fails e.g. due to loss of fluid, you can still bring the car to a halt through a separate braking system. And also if the driver has a heart attack or is otherwise suddenly incapacitated the passenger can reach across and activate it (in the US at least; here in the UK the passenger wouldn't be able to reach since the stalk is still on the RHS of the steering column!).
     
  19. MagicDoc

    MagicDoc Member

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    Woof,
    I am interested in your comment about an "advanced driving class". I have recently moved to TX from KS. The drivers in Texas are much different. I will let you figure it out. I would like to take an "advanced driving course"...not the AAA Auto Safety class or the Highway Patrol Active Pursuit course ( limited to law enforcement ), but some course to that teaches defensive driving or perhaps what you described as advanced driving. Would you elaborate on this course? thank you!
     
  20. zwede

    zwede 2013 P85+

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    Obviously the answer is we drive much better here. :)

    I'd recommend you go to a local autocross.

    Autocross Solo Events In Texas - Where2Race

    I've been to many in the DFW area and they are always very newbie friendly. It gives you a chance to toss the car around at low-medium speeds (usually top out around 50 mph) in a controlled environment. There are no cars to hit.
     

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