Sudden Unexpected Acceleration today

[Daniel in SD]

This thread scared the crap out of me. My wife is already scared of driving it. Glad that there's an update that prevents accelerating at something now.

Every car has the same flaw. The brake and the accelerator pedal are right next to each other. Very rarely someone presses the accelerator when they think they’re pressing the brake.
I suppose you could learn to brake with your left foot.

 

[RayK]

So much easier and faster and less fiddly to stomp the brake. Selecting Neutral takes a bit of thinking, choosing the correct stalk and moving it the correct amount, and waiting for a couple of seconds.

Stomp the brake. Everybody knows how to do that.

Yeah, well that really wasn't the gist of my question. Undoubtedly it's easier and faster to hit the brake but would putting the car into neutral work to cancel the acceleration?

 

[DonTom]

Why indeed. I can't figure out why anybody would consider doing that. Who is saying to press both? And even if you were to press both.... as other have said several times in this thread... the accelerator does nothing.

The question was "is there a kill switch?" And the answer is yes. It is the brake pedal.

I was actually asking if there is a way that is fool proof to kill the motor. For an example of what I mean, the kill switch did NOT work on the Zero motorcycle that I mentioned--but the key did, as that kills the power from the battery, doesn't require any type of data or anything like that to stop the motor.


-Don- Auburn, CA

 

[Yggdrasill]

I was actually asking if there is a way that is fool proof to kill the motor. For an example of what I mean, the kill switch did NOT work on the Zero motorcycle that I mentioned--but the key did, as that kills the power from the battery, doesn't require any type of data or anything like that to stop the motor.

Not sure if the various ways of cutting power all use software, but if they do, and in some theoretical situation the motor goes to full power and stays there, just press the brake. The brake is more powerful than the motor and will stop the car, no matter what the motor is doing.

As a backup - pressing the park button will engage the emergency brake.

 

[Peteski]

I had a Volvo that suddenly went to full throttle (it was an electronic throttle control, no cables - so much for throttle signal error safety shut off!) and stayed there while I was cruising down a fast dual carriageway. I started picking up speed and then once I realised something was badly wrong I just hit the clutch (manual car) and then put it in neutral, at which point there was obviously no drive and the engine just bounced off the rev limiter for about 30 seconds before lunching itself while I just coasted to a halt! It was not a nice experience for sure. If this happened in the Tesla I would first hit the brakes and then try to select neutral while slowing down. Either way it would slow down on the brakes.

 

[Candleflame]

Why indeed. I can't figure out why anybody would consider doing that. Who is saying to press both? And even if you were to press both.... as other have said several times in this thread... the accelerator does nothing.

The question was "is there a kill switch?" And the answer is yes. It is the brake pedal.

Altlogics post said " Easy in a Tesla. Hit the brake pedal. The car will cut power if both pedals are pressed."

 

[mongo]

Altlogics post said " Easy in a Tesla. Hit the brake pedal. The car will cut power if both pedals are pressed."

Which is a confusing response if, in the hypothetical situation, the accelerator is not initially pressed.

In other words, the SW fails and the the car is accelerating without the go pedal being pressed.

Rpot communication issue is that pressing the brake alone (or press and hold parking brake button) is sufficient, one does not need to press the brake and accelerator (both).

It is not a two input required (brake and go) kill switch, rather the brake overrides the accelerator and motors.

 

[Krazaak]

Yeah, well that really wasn't the gist of my question. Undoubtedly it's easier and faster to hit the brake but would putting the car into neutral work to cancel the acceleration?

No, there's no neutral position in the gearbox. Neutral is simply a software position where the motor provides no accel or regen torque to the wheels. If this theoretical condition in which power was erroneously applied to the motors (something that has never happened in a Tesla to the best of my knowledge) existed, then neutral likely wouldn't help.

 

[dsvick]

but why press brake and accelerator pedal at the same time then?

Altlogics post said " Easy in a Tesla. Hit the brake pedal. The car will cut power if both pedals are pressed."

I'm betting he forgot a word in his post and it should have said:
Easy in a Tesla. Hit the brake pedal. The car will cut power even if both pedals are pressed.

 

[Peteski]

No, there's no neutral position in the gearbox. Neutral is simply a software position where the motor provides no accel or regen torque to the wheels. If this theoretical condition in which power was erroneously applied to the motors (something that has never happened in a Tesla to the best of my knowledge) existed, then neutral likely wouldn't help.

Good point and in fact there is no way to physically disengage the motor drive with no clutches and fixed gear drives. You are totally relying on the motor controllers to remove power. But nonetheless, stamping on the brakes will get you stopped even with full power applied. Once stopped on the brakes you would then have to kill all power to the motors. Likewise, I've never heard of this happening on a Tesla or any other EV for that matter. There are plenty of sensor failsafes in place to prevent this kind of scenario getting out of control. You are far more likely to end up in a limp home power mode, or stranded with zero power if something goes wrong with the electronics, rather than uncontrolled maximum power!

 

[acoste]

There are many reports of unintended car makers from various brands. (Toyota's issue was not caused by the floor mats) It is possible that the acceleration control loop fails in a way that results in an unexpected acceleration, but the brakes should stop the car. The brake control system is able to prevent to stop the car (think about ABS) however it is very unlikely that both systems fail at the same time in a specific way.

So I think there is a possibility that someone hits things due to the slow reaction time of a human, but in general people should be able to stop the car with the brakes in a reasonable distance.

 

[chronopc]

I didn't read all 24 pages of this post, but was there ever a conclusion regarding whether the driver stepped on the accelerator or the brake?

 

[StellarRat]

I didn't read all 24 pages of this post, but was there ever a conclusion regarding whether the driver stepped on the accelerator or the brake?

No idea. All I know is that the latest software version is supposed to prevent you from driving through your garage door from a standing stop.

 

[chronopc]

No idea. All I know is that the latest software version is supposed to prevent you from driving through your garage door from a standing stop.

I wonder if anyone has tested that feature.

 

[StellarRat]

I wonder if anyone has tested that feature.

If it was "tested" would anyone admit to it?

 

[chronopc]

If it was "tested" would anyone admit to it?

If it worked

 

[super20g]

I wonder if anyone has tested that feature.

Someone needs to livestream the test... Will be informative either way.

 

[balzary]

I wonder if anyone has tested that feature.

Not by driving at a garage wall... but I did have an issue with it.

We had snow the other day and I guess it covered the sensors at the front or something. I get to a light and sitting there waiting and when it went green it wouldn't let me move, screaming at me that there is an obstruction... and I'm at the freaking light.

I can't remember exactly what I did to get it going, was in a bit of a panic. I remember sawing the wheel a bit, perhaps it moved the snow enough. So it will do something, had the same effect on slowing my acceleration as well when moving.

 

[StellarRat]

Not by driving at a garage wall... but I did have an issue with it.

We had snow the other day and I guess it covered the sensors at the front or something. I get to a light and sitting there waiting and when it went green it wouldn't let me move, screaming at me that there is an obstruction... and I'm at the freaking light.

I can't remember exactly what I did to get it going, was in a bit of a panic. I remember sawing the wheel a bit, perhaps it moved the snow enough. So it will do something, had the same effect on slowing my acceleration as well when moving.

Sounds like an "unintentional" consequence of the "fix". There probably should be an override for cases like this. Maybe a "go anyway" choice that accompanies the message. Surely, if it was a good warning the driver couldn't complain if they overrode it then proceeded to drive through the garage door anyway.

 

[Oldschool496]

Here is my chance to test the great Tesla/Brembo brakes, oh boy I can't wait, I'm gonna really clamp down on them hard, real hard.

Loaner, coming off highway, long off-ramp, green light, left hand turn, accelerating hard into ramp and beyond, applying brakes hard and the infamous tone I have never heard, applying brakes harder yet, car is accelerating more and more as I press harder and harder, I was already pushing the envelope hard and its getting worse. MUCH WORSE. Things are happening really fast now, there is not much time to react to anything.

lift foot and car slows down a bit(regen only) and we make our left turn at really high speed with concrete overpass abutment 40 feet high and 60 feet wide, straight ahead that surely would have killed us.

Had one foot on both Accelerator and Brake simultaneous no doubt in my mind.

2012 Signature P85, that I swear to this day those pedals are closer together(configured differently perhaps) on that car(any SIG owners out there to confirm or deny this possibility please chime in) then my MS or other MS's. I never confirmed that. Scared the .... out of us.

Done it and hope it never happens again. The tone is forever registered in my brain albeit a really bad time to learn what the tone is/was.
I have heard it since at low speed maneuvers in my car briefly with two footed slow maneuvers(which MS cannot really or need to drive two footed anyway).

I fully admit it was my fault and thats my story. I'll leave the brake testing to others. My brakes work fine.

Rolling the car also flashed in my mind, I recall all that weight across the entire bottom of the car from a video Elon Musk pointing to the low center of gravity in some scene. All this is happening in my head at the moment.

It had 21s and new tires and we skated right around the left turn at unusually high speed. If cars were in front of me at any point, I don't even want to think about that.