Collision Avoidance overrode brake press and causing car to veer and hit the curb

[mcfuzz89]

Op.. you say you have video of this happening. I am always skeptical of anyone that posts saying "My friend / My co worker / My buddy" had this fantastical thing happen... anyone seen this before?

It always sounds like "Im asking for a friend, yeah thats it, a friend...." who doesnt actually exist. Why do YOU have your "buddys" video, yet didnt post it in this situation to prove what you are saying?

You even know enough about it to draw a diagram, but it wasnt you, it was your buddy, right?

Its also highly (highly highly highly) unlikely the car would override any sort of manual input. the car lets you drive into a garage or other stationary object (see all the "unintended acceleration" threads).

This really sounds like someone trying to find some way out of "I panicked, yanked the wheel and drove into a curb"...err your buddy did, yeah.

I can understand your skepticism - but I assure you that it is not my car.

Damage to the car in question:

And my car:

Regarding the video - I'll ask permission to post it and will gladly do so.

 

[mcfuzz89]

The Tesla Model 3 is not brake by wire.

Moreover, human steering and braking actions always override the computer systems unless braking causes the wheel(s) to lock, in which case ABS/ traction control kicks in.

Pedal error is dramatically more likely in this instance than any fault in the Model 3.

Thanks.

As I said before - I don't discount pedal error. But consider the following: if you're maintaining speed by pressing the "gas" pedal and an emergency occurs, are we saying that the "gas" pedal was pushed even further rather than instinctively push the brakes?

 

[Pedals2Paddles]

We don't know what your friend actually did or didn't do with his feet and hands as there is no video of his body. What we do know 100%, is that what he described is not possible. He's either confused about the events, which is common. Or misrepresenting the events to feel less like he made a mistake, which is also common. Maybe he stepped on the wrong pedal. Maybe he didn't brake at all but thought he did. Maybe he braked later than he thought he did. We can all theorize what may have happened up down and sideways but there is no way to prove any of those theories without log analysis. We can however disprove his claim, because it is physically impossible.

 

[compu85]

There was some discussion amongst some of my peers on whether there is some kind of a "brake-by-wire" technology in the cars - is there something like this in the Model 3? Or is the pedal connected directly to the master brake cylinder through an electric booster?

The Model 3's brake pedal is connected to the iBooster, which is connected directly to a conventional master cylinder and ABS install.

the iBooster works a lot like electric power steering. It helps you push the pedal, but the pedal moving is what does the application of the master cylinder. That's why the pedal moves when the car applies the friction brakes - just like how the wheel turns when in auto steer.

In other EVs, like my Cadillac for example, the system can isolate the master cylinder from the abs & friction brakes. The pedal does not move when in radar cruise and the car uses the friction brakes.

-J

 

[brkaus]

Thoughts -

- If diagram is accurate, that's a long way to go after hitting the brakes while accelerating from a complete stop. Shouldn't be that much momentum

- Gravel, sand, water on road that would make the ABS kick in?

- Brake linkage is mechanical. I'm not sure about the master cylinder configuration. Many cars have dual circuits so failure in one circuit woudln't take out all the brakes.

 

[MasterC17]

LOL these threads are so silly. The brake pedal will over-ride the acceleration of the vehicle 100/100 times. Try it in your car. Put one foot on the brake as hard as you can and then press the accelerator. Car is not going to move. End of story.

People will rationalize the most ridiculous things when trying to clear their conscious of fault.

 

[brkaus]

BTW - you have the video. Contact the police and the insurance carrier of the van. If the van truly forced the car off the road they may be at fault. If they did have room, moved over, and the Tesla didn't yield... well, then it's the Tesla's fault for not controlling their car. The typical person in back is usually at fault situation.

 

[avalpert]

Thanks.

As I said before - I don't discount pedal error. But consider the following: if you're maintaining speed by pressing the "gas" pedal and an emergency occurs, are we saying that the "gas" pedal was pushed even further rather than instinctively push the brakes?

Yes, that is not an uncommon human error at all - a google search would show you how common it is.

This is a big advantage of one pedal driving, once it becomes habit.

 

[Paddy3101]

My guess
1) Emergency Lane Departure Assistance kicked in, avoiding going 'out of the lane' and hitting the van. Which it sounds like it was successful at.
2) Braking did work, but ABS may be limiting stopping, as car is trying to steer at the same time. Probably was stopping, but not as fast as was wanted, needed. Was it wet?

 

[MentalNomad]

As I said before - I don't discount pedal error. But consider the following: if you're maintaining speed by pressing the "gas" pedal and an emergency occurs, are we saying that the "gas" pedal was pushed even further rather than instinctively push the brakes?

It's likely they lifted their foot off the accelerator and then, instead of the brake, they slammed their foot down on the accelerator again.

This is classic pedal error, and happens much more often than you think - and the people who do it always insist they didn't.

This happens because, at the time, the brain is confused.

They don't remember it as a mistake because their memory was laid down by a brain that is confused. They remember their confused belief, not what they actually did.

 

[mcfuzz89]

My guess
1) Emergency Lane Departure Assistance kicked in, avoiding going 'out of the lane' and hitting the van. Which it sounds like it was successful at.
2) Braking did work, but ABS may be limiting stopping, as car is trying to steer at the same time. Probably was stopping, but not as fast as was wanted, needed. Was it wet?

It wasn't wet, but the intersection where it happened has a downward slope so it could have contributed to the effect of not slowing down faster than it should.

But your explanation seems to be consistent with the reported experience. In any event - only damage is to the wheels; no other component was damaged according to the Service Center.