Unintended acceleration

[Whereitis]

Just happened to me today Brakes failed Car accelerated until it crashed

I'd like to hear more details about your incident. How did the brakes fail? Was it a sudden leak that led to no response to pedal pressure? Was it a jammed caliper? Was it something else? Where were you and what were you doing at the moment the crisis started? How fast were you going at the time? Did you try to stop it, and if so what did you do?

 

[808Pants]

... but my understanding is that the family called the cops for help.

Leave it to Fox to omit that vital detail.

 

[DuploCar]

Are everybody ok?

 

[Whereitis]

You may find this one an interesting exception to that!

It brings up a very valid concern about 100% drive by wire controls. If the throttle input sticks, and the car won't shut off, options are very limited with no physical disconnect at hand.

This news report was about a 2022 Honda Pilot, so its relevance to BMW i3 issues is tenuous at best. Things not mentioned in the Fox News report include did he turn off the ignition, and if that didn't work did he try putting the transmission in neutral? That might have blown the motor but so what, at least he would have coasted to a safe stop. I once had a 73 Corolla and while driving it down a long hill with 2 passengers in it, an insufficiently tightened stud (my bad there) rattled loose from the air cleaner (bad design, Toyota), dropped into the carburetor and jammed the throttle wide open. Even as a relatively new driver, I knew to immediately put the clutch in, and when that made the engine race I turned off the ignition. Once the engine turned off I put the transmission in neutral and turned the key back on, thereby unlocking the wheel so I could steer. This entire process happened in under 2 seconds, and I braked the car to a safe stop on the shoulder. In hindsight (since I was 18 at the time and had only had a driver's license for about a year), the things I needed to try to get the car to stop accelerating were instantly clear and obvious, so I have very little respect for the kid who was unable to think clearly enough to try any of these things during the several minutes he was flying down the highway.

 

[eNate]

I encourage any i3 driver reading this to try the following experiment: on an appropriately vacant road, drive at a suitable rate of speed and while maintaining that speed with the accelerator pedal, use your left foot to lightly brake, then moderately brake, then heavily brake.

You'll easily identify the braking force (possibly pedal position) threshold where power is cut to the motor, no matter how hard you stomp on the accelerator pedal.

I don't know what level of system failure would be necessary for an unintended acceleration event to occur simultaneously to the motor cut-off function also failing, but that's a basic level of prevention that is designed to prevent this from happening. Definitely a step up from a stuck throttle condition in an ICE vehicle

 

[ksnax]

This news report was about a 2022 Honda Pilot, so its relevance to BMW i3 issues is tenuous at best. Things not mentioned in the Fox News report include did he turn off the ignition, and if that didn't work did he try putting the transmission in neutral? That might have blown the motor but so what, at least he would have coasted to a safe stop. I once had a 73 Corolla and while driving it down a long hill with 2 passengers in it, an insufficiently tightened stud (my bad there) rattled loose from the air cleaner (bad design, Toyota), dropped into the carburetor and jammed the throttle wide open. Even as a relatively new driver, I knew to immediately put the clutch in, and when that made the engine race I turned off the ignition. Once the engine turned off I put the transmission in neutral and turned the key back on, thereby unlocking the wheel so I could steer. This entire process happened in under 2 seconds, and I braked the car to a safe stop on the shoulder. In hindsight (since I was 18 at the time and had only had a driver's license for about a year), the things I needed to try to get the car to stop accelerating were instantly clear and obvious, so I have very little respect for the kid who was unable to think clearly enough to try any of these things during the several minutes he was flying down the highway.

The point was that engine and transmission operation are 100% drive by wire in that car, and that a computer failure would prevent disengaging the engine and drivetrain. I.e., there was no turning it off and no taking it out of gear option.

 

[Whereitis]

You may find this one an interesting exception to that!

It brings up a very valid concern about 100% drive by wire controls. If the throttle input sticks, and the car won't shut off, options are very limited with no physical disconnect at hand.

The point was that engine and transmission operation are 100% drive by wire in that car, and that a computer failure would prevent disengaging the engine and drivetrain. I.e., there was no turning it off and no taking it out of gear option.

I was not aware that the 22 Pilot was 100% drive by wire. There needs to always be a backup option in case of computer failure. Thanks for the clarification.

 

[eNate]

Here's some interesting context to add to the Honda Pilot incident. Take it with a grain of salt as it's just another auto forum, but worth a read:

https://www.ridgelineownersclub.com...ing-into-the-back-of-a-police-car-cnn.244856/

No defects found (news story):

https://www.valleynewslive.com/2025...-runaway-car-closed-no-vehicle-defects-found/

My main thing is that this kid's story has all kinds of holes in it, but with sensational footage to make it compelling and sharable, there's no holding it back. Based on what we've got, I wouldn't cite the incident as an example, but I also wouldn't cite the news story of Honda's "no fault" findings as 100% ironclad. However, I do think it's indisputable that multiple safeguards would have had to fail or have been bypassed for this to happen as described.

 

[SocialCat50]

I'd like to hear more details about your incident. How did the brakes fail? Was it a sudden leak that led to no response to pedal pressure? Was it a jammed caliper? Was it something else? Where were you and what were you doing at the moment the crisis started? How fast were you going at the time? Did you try to stop it, and if so what did you do?

I was in a parking lot going 5 mph when it suddenly accelerated and continued to accelerate Couldnot steer or brake I hit two parked cars and continued to increase speed until I crashed into a parked truck

 

[eNate]

So your car experienced simultaneously a hydraulic brake system failure, a motor cut-off circuit failure, some sort of stuck accelerator failure, and the steering also failed at the same time? That sounds awfully... not coincidental, but nearly conspiratorial in that somebody might have tampered extensively with your car to make all of those systems stop functioning at the same time. Scary!

 

[mojo]

Couldnot steer or brake I hit two parked cars

Wow - incredible experience. What did the brake pedal do - go to the floor? What happened to the steering?

I don't think you've said where you are, but in the UK or US an accident like that would result in the car being forensically examined, I would have thought. Has that happened yet?

 

[eNate]

Don't forget this resource...

 

[sailnavy]

Wow, that's unbelievable.

 

[sailnavy]

Just happened to me today Brakes failed Car accelerated until it crashed

And you joined the group just a few days ago. What are the odds?

 

[ksnax]

That does not sound like a generic system failure. The brakes on these cars are absolutely capable of stopping it at full motor power and parking lot speeds. There is more to the story, and the only people telling this sort of story are doing hit-and-run posts.

'Pics or it didn't happen', as the saying goes . .

 

[eNate]

And you joined the group just a few days ago. What are the odds?

Well technically the crash happened first, then they joined this forum.

I won't dismiss a report of a crash as a fabrication or anything nefarious -- I'm accepting that it happened and was probably traumatic.

However there is this tendency on another non-i3 forum that I frequent that reports of sudden unintended acceleration to come from first time posters insisting there is a defect with the car, usually without an EDR pull. Even in the few cases they have retrieved the data, the report of "no abnormalities" gets dismissed as part of the underlying defect / cover-up by the manufacturer.

Meanwhile tenured members of the forum report no such occurrences, and statistically speaking some of us should have, had this supposed defect actually existed.

Pedal confusion is a real thing, and EVs introduce a new human factor in that the accelerator pedal is also used for slowing. None of us can say with any certainty or authority that that's what happened in any particular case, but it's not uncommon, even in ICE cars.

 

[Whereitis]

There have been numerous reports of unintended acceleration over the years, starting (in my recollection) with the infamous Audi 5000 incident that almost knocked Audi out of the the US market back in the day. I'm sure there are a few that are legit (I had one of my own in an old Toyota once, however I was able to safely stop the car without the incident making the 6:00 news), but the vast majority of them seem to be devoid of details that would validate the accuracy of the report, and in the few possibly legit ones, the inability of the driver to know how to operate their own vehicle well enough to stop it safely is astonishing to say the least. In more recent reports, the number of integrated safety systems that would have all had to fail simultaneously for it to happen reaches a Chernobyl level of incredulity. Not that it couldn't happen, but what are the odds and how stupidly must the operator have acted in the moment?

 

[eNate]

how stupidly must the operator have acted in the moment?

This may be the only area where I differ with you. After any person who has driven without similar incident for decades, to find the car inexplicably racing forward seemingly uncommanded doesn't put the driver in a good place (or give adequate time) to evaluate what's going on, especially if their muscle memory is telling them that they are stepping on the brake pedal and the ingrained instinct is to press harder. I don't think it's a matter of intelligence or ability to reason unless it's truly a runaway-car-on-the-freeway type of scenario where there is a moment to recollect and assess, and even then it might be a big ask for somebody in a panic who finds themselves traveling at 100 MPH.

I also understand the immediate instinct to blame the car. "Couldn't have been me; I've never done that before." Even in the face of logic and sometimes evidence to the contrary.

 

[Whereitis]

This may be the only area where I differ with you. After any person who has driven without similar incident for decades, to find the car inexplicably racing forward seemingly uncommanded doesn't put the driver in a good place (or give adequate time) to evaluate what's going on, especially if their muscle memory is telling them that they are stepping on the brake pedal and the ingrained instinct is to press harder. I don't think it's a matter of intelligence or ability to reason unless it's truly a runaway-car-on-the-freeway type of scenario where there is a moment to recollect and assess, and even then it might be a big ask for somebody in a panic who finds themselves traveling at 100 MPH.

I also understand the immediate instinct to blame the car. "Couldn't have been me; I've never done that before." Even in the face of logic and sometimes evidence to the contrary.

Point well taken. I guess we all need to be more diligent, especially in this age of self-driving cars. My new RAV4 Prime has distance-keeping cruise and lane-keeping, but I only rely on any of it for a few seconds at a time while I change the radio station or something, not for minutes or hours. But I've heard there are those who are more relaxed about this (Teslas come to mind), with predictable results.

 

[eNate]

I've become quite reliant on ACC, especially over distances. It holds intended speed better than I could ever hope to, and it's far more attentive to following distances and slowdowns than I might be as my brain wanders during a multi-hour road trip. I wish the i3 had radar or at least a bit more refined optical-based system. But after a long drive I do find that with ACC I feel much fresher throughout, which I hope would pay off if there were suddenly some emergency braking or maneuvering where I had to quickly take over. I mean, it's not like it lets me doze off.

Most of these runway acceleration scenarios as described seem to happen in parking lots or at intersections, go figure.