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Hill Assist

Hill Assist

I really find it strange that in a 2012/2013 car there is no hill-hold feature standart. Does anybody know how the braking system of the Model S works? Is the braking pedal mechanical connected to device (magnetic or hydraulic) that activates and releases the brakes or is the pedal just connected to a sensor that sends an electrical signal to the braking device? In the latter case it should not be difficult to program a delay of 2-3 seconds between the release of the brake pedal and the release of the brake and should not take long to develop and implement.

Kludge | January 31, 2013

Sounds like hill assist will be a future feature. Disable it if you don't WANT to use it.

Freedom of choice; it's a beautiful thing!

LK | January 31, 2013

@nickjhowe. I read that as we'll. But, your options are limited. As long as your not mashing the gas, you don't have to worry about the firing off of a light and your car turning off...

JaneW | July 13, 2013

You have hill hold. It's called the accelerator. Works fine in Colorado mountains. Should work in SF, too.

KevinR.co.us | July 13, 2013

+1 JaneW

EVMD | September 5, 2013

I see two problems here, many new owners come from green cars like Prius and Volt, other buyers like me are changing similar value cars like Mercedes, BMW, Jags, Audi and so on. This simple features like hill assistant are standard from years and asking for this technological awesome car to have it is not big deal. Is software that is it. That is the difference between a luxury car and standard automobile.Whit the same argument I can say Why internet access I have my Ipad!! why parking sensors I have mirrors!! Why electronic seats I have hands!! why electronic trunk I have hands too!! Today luxury car means way higher safety than a regular automobiles.
Saying that this is the reply I got from Tesla.

_________________________________________________________

Thank you for reaching out to us at Tesla Motors, my name is Peter, I work on the Ownership Experience team, and I am happy to answer your question. At this time Model S does not have a "hill hold assist" feature. However, this is a much requested enhancement of our vehicle and I have added your expressed interest to our feedback database for our software management team.

Please feel free to reach out to us again if there is anything else we can answer or assist with.

Kind Regards,

Peter

redders | September 5, 2013

Some really dumb comments on here about creep fixing hill assist, it's okay if you roll back a little bit, don't know how to drive if you roll back. No, no, no.

We need hill start. Creep assist doesn't fix it. It's dangerous and the driver shouldn't be doing clever stuff to compensate.

EVMD | September 5, 2013

Creep assist it does not compensate for steep hill or steep parking exits as far as I know. I still waiting for my MS, perhaps some owners can clarify.

SeattleSid | March 6, 2014

Reading this and other threads it seems that gentle pressure on the go pedal works just fine. My question is: isn't that hard on the motor? I think of an electric motor, say a fan, being held and humming and getting hot because it's not turning. What's different here?

LMB | March 6, 2014

(LMB spouse)

@SeattleSid - It's a different kind of motor. The fan motor is designed to run at speed and uses its torque at 0 RPM just to accelerate to its operating speed. The induction motor in the Tesla uses a variable frequency input to generate more or less torque as required.

carolinagobo | March 6, 2014

This issue was discussed before and you will find a lot professional drivers here that think that the use of hill assistant is not needed if you know how to drive.....really....let's go to apply the same rational for all the new car advance technologies.

1-Why blind spot sensor "You don't know how to set the rear mirrors and look around" scary people doesn't know hot to drive

2- ABS Wow I can't believe people doesn't know how to pumping the brakes before stops.

3- Folding mirrors...Ridiculous we have hands.

4- Bluetooth. What a waste of money here you can connect A wire headset.

5- Parking sensors...Well if you know how to drive you don't need it

6- rain sensor.... WHAT you can't figure out how to turn on your wiper blades??

YES HILL ASSISTANT should be an standard, is just software and Tesla should update the cars with this future, jaguar make it easy, put the electronic break and as soon you hit the accelerator the brakes release it, Tesla can add a button call hill assist to do the same.

SeattleSid | March 6, 2014

Thanks, LMB/S: I take it there's no problem. For the record, I've always driven a stick and have had no problems on hills, so I don't really care about hill assist per se. I did note, however, on a test drive, that the Tesla slid back some on a hill; so it'll be necessary to deal with that with one or another driving technique. Using the accelerator would be simple, and, evidently, not harmful. Using heel/toe, or two feet is easy, too.

ChopinBlues | March 7, 2014

A neighbor of mine who also has a Tesla claims this feature was added in the latest release, and is activated by a tap on the brakes. I saw nothing about this in the 5.8.10 release notes, nor does it seem to work in my car. Is he imagining things?

shop | March 7, 2014

Afaik, there is no hill assist yet. Rumored to be in a future release. If you have the creep setting on, it works as a hill assist as long as the hill isn't too steep.

David Trushin | April 14, 2014

Now that hill assist is in 5.9, has anyone tested the behavior of brake and accelerator at the same time? Hopefully they changed it to give brake priority in all cases.

DaphneGreen | April 14, 2014

Yes, it has hill assist now. I haven't used it on a big hill, but it held on a little incline.

2-Star | April 14, 2014

It also seems to hold on level ground if you press the brake hard and release it, like at stop light. Then just press accelerator to resume forward motion.

zwede | April 14, 2014

Yeah, took me by surprise when it activated on my (very steep) driveway. I like it so far.

DavidN | April 14, 2014

The new hill assist with 5.9 works great, even on steep hills.

However, there is still no brake priority override of the accelerator when the brake pedal is pressed first. So it's still possible to inadvertently press both pedals while braking (it's happened to me a couple of times; the car's close pedal spacing doesn't help), which extends stopping distance significantly. A safety issue, in my opinion.

Hopefully this will be corrected in 6.0; it's an easy software fix.

Brian H | April 15, 2014

Yeah, call it the Fat Foot Flaw! >;p

ye | April 15, 2014

How does it work? Does it use the brakes to hold the car, or does it use the motor?

ye | April 17, 2014

bump

rdalcanto | April 17, 2014

I came to a stop on a hill using only the accelerator, and hill assist did not activate. You have to stop with the brake pedal depressed to activate the function. Then it worked well.

ye | April 17, 2014

Ok, that's interesting. It could still use the motor to keep the car from rolling backwards, though, even though you stopped using the brakes. So I wonder whether it does that.

joehuber | April 17, 2014

It uses the brakes.

ye | April 17, 2014

Thanks. May I ask how you know?

rdalcanto | April 17, 2014

I think it uses the motor. When I press the brakes on a hill and stop, and then let off the brakes, the energy usage goes up a little, and I can kind of feel the motor holding it. It only holds the car for about 1-2 seconds before it lets the car start rolling backwards. Hill assist seems to really be designed to hold the car just long enough for your foot to go from the brake to the accelerator. Well done in my opinion.

ye | April 17, 2014

Hmm. I guess it was good I asked. :-)

I'd imagine that using the motor would allow for a smoother start, as the car would otherwise have to coordinate letting off the brakes with increasing the power to the motor.

Captain_Zap | April 17, 2014

I was wondering if the changes in the pedal map and were due to the hill hold modification.

Low CG | April 17, 2014

Works great.

tezzla.SoCal | April 18, 2014

using the motor wouldn't work on downhills though.

DickB | April 18, 2014

@ye
The electric parking brake is use for the hill-hold. You can hear it when it goes on and off.

_thierrY | April 18, 2014

@tezzla : it surely does not work downhills because it's purposeless. The goal of the feature is to prevent the car from going to the opposite direction, not the intended direction...

DallasTXModelS | April 18, 2014

@thierrY

If you think about what you said you'd realize how dumb you sound.

If you are stopped facing up hill and take your foot off the brake it holds you 1 second so you don't roll back and hit the car behind you.

If you are parked in a parking place facing downhill it holds you 1 sec so you don't roll forward before accelerating while in reverse. If you are parallel parked facing downhill with a car in front of you and don't have hill assist you would roll forward into the next car before the motor pulled the car back.

It is not pointless to work in both directions.

Rocky_H | April 18, 2014

Definitely using the brakes. Bjorn Nyland did a video when he got 5.9, where he demonstrated a lot of the new features. You can definitely hear the brakes coming off the rotors when it lets go on the hill hold demonstrations.

procarl | April 18, 2014

@_Thierry

Release Notes are very clear that the application is for both directions.

There really is much to be said for thinking (or reading) before speaking.

_thierrY | April 18, 2014

@DallasTXModelS @_Thierry : you are saying the same thing as me : "The goal of the feature is to prevent the car from going to the opposite direction, not the intended direction..." (so I wonder why you are so rude).

@Tezzla was talking about the impossibilty to use to motor to stop the car while going in the intended direction. I beleive it's purposeless and thats why Tesla did not implemented it.

_thierrY | April 18, 2014

Idem for @procarl

ye | April 19, 2014

So far, the consensus seems to be that it's the brakes. Anyone else want to join rdalcanto in the motor camp? :)

I will watch Bjørn's video and see what I think.

I don't know whether the motor is used, but it certainly could be used. It's perfectly capable of providing torque in both directions.

ye | April 19, 2014

Ok, I watched the video. I don't know how the parking brake normally sounds, but I definitely heard something, and I don't see why the motor would make any noise at all.

If you move your foot from the brake to the accelerator very quickly, does the parking brake release right away, or does it still take some time?

ir | April 19, 2014

Hill assist disengaged instantly when I switched to the accelerator pedal. No discernible lag.

I also tried re-engaging the brake while hill assist is on (took my foot off and braked again instead of accelerating). The brake pedal is super stiff, just like it is before you start the car. So it definitely is the brake (not motor) and I suspect it's the hydraulic not parking brake because of that stiffness.

NKYTA | April 19, 2014

I've noticed with 5.9 (.94) that it seems to require a firmer push on the brake to engage hill assist. More firm than when I was on .92.

rdalcanto | April 19, 2014

If hill assist doesn't use the motor, why does the orange line move up significantly as soon as you release the brake pedal and hill assist is holding the car still on the incline?

rdalcanto | April 19, 2014

P.S. - I tested several times on a steep hill, so what ever is holding the car has to work hard to keep it there.

DickB | April 19, 2014

@rdalcanto
The hill assist does use electric. The parking brake on the rear wheels has an electric motor that applies the brake pads. It's the parking brake that come on for the hill assist.

Pungoteague_Dave | April 19, 2014

The parking brake does not use an electric motor. It has an electronic servo system that hydraulically activates a second set of standard brake calipers brake pads on the rear brake rotors. No motor involved.

Rheumboy | April 19, 2014

I love hill assist......now I don't have put my leg out of the car to hold

Bighorn | April 19, 2014

@Rheumboy
Yabba dabba doo!

Rheumboy | April 19, 2014

LOL

ye | April 19, 2014

ir said: "Hill assist disengaged instantly when I switched to the accelerator pedal. No discernible lag. I also tried re-engaging the brake while hill assist is on (took my foot off and braked again instead of accelerating). The brake pedal is super stiff, just like it is before you start the car. So it definitely is the brake (not motor) and I suspect it's the hydraulic not parking brake because of that stiffness."

That makes sense. I guess it somehow uses the anti-lock braking system, which is able to apply the regular brakes when it wants to. Also, the ABS can apply and release the brakes very quickly. I think I remember reading somewhere that the parking brake is a bit slow to engage and disengage. Is that true?

ye | April 19, 2014

Pungoteague_Dave said: "The parking brake does not use an electric motor. It has an electronic servo system that hydraulically activates a second set of standard brake calipers brake pads on the rear brake rotors. No motor involved."

Are you sure? I always thought that the reason why parking brakes are generally cable operated, rather than hydraulically operated, is that a car's parking brake is applied continuously for long periods of time and hydraulics have a tendency to leak down under those conditions. So I'd be surprised if the Model S had hydraulic parking brakes.

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