3 Unintended Acceleration events when parking my Tesla S P in my garage.

[Rajainmiami]

Good Morning

I just had a freak accident while driving my Tesla Model S 100D 2018
I was Stopped in traffic on D with foot on brake
Suddenly car jumped forward by itself and hit the car in front Of me, but then backed up and moved forward again hitting the car twice in succession while I am in the driver seat trying to stop it !!!
I pressed P and it stopped
I was dumbfounded trying to explain to three cars in front of me that I have no idea what happened !! I was stopped and waiting with my foot on the brake. !!!!!
I have read about unintended acceleration but this happened while stopped in traffic with no intervention from me. Any thoughts? Fortunately everyone was safe with minor bumper damages.

I have had this car since 2018 and this is the first time it has done that . I am planning contact Tesla tomorrow. I am in Miami and temp is in the high 70’s so no overheating and back from a 0.6 mile drive to the pharmacy

 

[DerbyDave]

I think your car has Dashcam. I hope you captured this on the dashcam. Tesla and your insurance company will need to work this out. Report the safety issue to NHTSA. Report a Safety Problem | NHTSA

 

[WilliamG]

Let me clear something up here: You're saying your car, in Drive, jumped forward, while your foot was on the brake, hit the car in front, and then put itself into Reverse, backed up, and then switched to Drive, and surged forward again..., hitting the car a second time....?

 

[wk057]

Car can't move if you're pressing the brake.

Period.

Like everyone else, by "trying to stop it" you pressed the accelerator pedal.

 

[Tam]

...foot on brake...

If you press and it moves, and the harder you press on it, the faster it accelerates, that's the wrong pedal for braking.

That's why one-pedal driving has value in your case: If you don't press any pedal, the car brakes, it won't move.

 

[HankLloydRight]

Even if you hit the accelerator instead of the brake, how did the car “back up” in order to ram the car twice?

 

[wk057]

Even if you hit the accelerator instead of the brake, how did the car “back up” in order to ram the car twice?

I could see them letting off the accelerator and rolling backwards, then mash the accelerator again.

 

[Mash]

Everything is possible, but I feel like it's ~1:1000000 chance of major electronics malfunction Vs wrong pedal application. Black box data is going to show it.

 

[gajafl]

Your incident was very different from mine. My 4 jumps in my SP happened only when I put the car in Park in my garage after getting the transmission very hot on 90 degree FL days. What happened to you is much more complex than what happened to me. Many other Tesla owners have reported similar weird experiences. All have been categorized as caused by human error an/or 'wrong foot' acceleration. I merely put my car in Park and it jumped forward 2 feet even with my foot mashed on the brake the 3rd and 4th times it happened. I now have a Plaid and to date no jumps. My jumps were related to high transmission heat which causes the Park Transmission Sensor to hesitate going into in Park. According to Robert Belt, an engineer who wrote a detailed and comprehensive article in 2018 about how this can happens, is because the Transmission Sensor shares the same ground as the TPS Throttle Sensors which during the hesitation send 4 impulses in one second to the TPS Sensors. The power of hitting the gas 4 times in one second, even in Chill Mode, over powers the brakes. Mine like yours was a shocking and horrific experience. Mine happened 4 times in my garage. The first two being the most damaging.
Your incident is hard to believe, but for what it's worth I believe it happened pretty much as you described. Who slams his Tesla into the cars in front of him twice in 10 seconds. Send any photos you have with a detailed letter to your nearest Tesla Service Center. They will request you bring your car in for inspection and Tesla will immediately download your data from your car. Send the same info to NHTSA. I doubt you will receive a response from Tesla. I sent 4 letters and photos and never received a reply yet the Support site states they will answer you in 48 hours. I also called 4 times. It is obvious that if Tesla acknowledged there was a problem every Tesla S from 2012 would have to be recalled. It happens so rarely and would be very costly so Tesla will ignore it happened. I know the incident will make you feel you can never trust your Tesla again. So many owners feel their car are infallible because of course it is a computer. I keep 4 near new laptops to make sure two are working correctly at all the times. Good Luck and sorry for costs and heartache such a weird incident like this can cause. Take care.

 

[ucmndd]

I could see them letting off the accelerator and rolling backwards, then mash the accelerator again.

Or the other car rolls forward giving the sensation of reversing in a panic. This plus the object aware acceleration feature changing the characteristics of how the car responds to the user input seem far and away the most likely cause.

 

[wk057]

Or the other car rolls forward giving the sensation of reversing in a panic. This plus the object aware acceleration feature changing the characteristics of how the car responds to the user input seem far and away the most likely cause.

I doubt it had much to do with this incident, but the Obstacle-Aware acceleration thing is idiotic, in my opinion. If I tell the car to go, it better f*ing go. If you need this kind of nanny protection from your own inputs, you shouldn't be operating a vehicle. Period.

I turn off the Obstacle Aware thing now since it almost got me killed twice when trying to turn onto a busy road. I've driven my Tesla vehicles for many thousands of miles and know how they perform and what I can and cannot do safely. If I punch it to get into a hole in traffic that I know I have the acceleration to successfully make, I expect the car to behave as it always does and get there as expected. Instead, this "safety" feature limited my acceleration twice when trying to perform such a maneuver, nearly getting me T-boned... and would have been perfectly safe within a sufficient margin otherwise. The first time I figured it was maybe a fluke, but after this happened to me twice I regularly make sure this feature is off... despite it magically re-enabling all the time.

 

[wk057]

This is a repost of your original post.

My original reply stands:

Car can't move if you're pressing the brake.

Period.

Like everyone else, by "trying to stop it" you pressed the accelerator pedal.

And this reply is, again, impossible:

I merely put my car in Park and it jumped forward 2 feet even with my foot mashed on the brake the 3rd and 4th times it happened.

Again, the car can not move if you have the brake pressed. It can't happen. The brakes are a mechanical system that can easily overpower even the most powerful Tesla vehicle motors. If you actually have your foot on the brake, the car _can_ _not_ _move_.

Like everyone else claiming such nonsense, you pressed the accelerator, not the brake.

I can't believe people still try to push this stuff...

 

[mangrove79]

The dashcam footage, or something equivalent that's indisputable, would have the final say in whether this happened as described. I'm sure any government agency in charge of investigations would also need to see such evidence. Please post here if you don't mind.

 

[wk057]

The dashcam footage, or something equivalent that's indisputable, would have the final say in whether this happened as described. I'm sure any government agency in charge of investigations would also need to see such evidence. Please post here if you don't mind.

Unless it's dash cam footage of the driver's feet, it's probably useless.

No one's disputing that they vehicle moved as noted... it's just that the driver unintentionally commanded it and is trying to blame the car instead.

 

[mangrove79]

Unless it's dash cam footage of the driver's feet, it's probably useless.

I wouldn't call it useless, but certainly not good enough in a court of law. I know there is zero chance of having footage of the driver's foot, lol, but just seeing concrete evidence of how the collision happened would answer some questions in my head, and I know other people here are interested as well. The lack of such evidence doesn't prove the OP is lying, it simply adds doubt. Again, this is a public opinion forum, not a court of law.

 

[Dan D.]

Again, the car can not move if you have the brake pressed. It can't happen. The brakes are a mechanical system that can easily overpower even the most powerful Tesla vehicle motors. If you actually have your foot on the brake, the car _can_ _not_ _move_.

Like everyone else claiming such nonsense, you pressed the accelerator, not the brake.

I can't believe people still try to push this stuff...

Nothing is ever absolute.

The pedal force matters, and some people cannot push hard enough. Minimum pedal forces have been mandated but there are still some people who can't achieve them. I don't know what the pedal force is to prevent a Model S from moving, but there is a number.

Here's an article on the topic https://www.autosafety.org/wp-conte...rakes-Will-Not-Always-Overcome-the-Engine.pdf that shows that a percent of the population are unable to press hard enough to achieve the maximum braking. They do achieve some braking, just not the maximum. Do we know the minimum force required to prevent the S from moving?


..the flaw in both tests was that they did not measure the brake pedal force. The drivers in both cases could apply whatever brake pedal force was needed to get the results they were seeking. It stands to reason that the stopping distances will be less if the brake pedal force is allowed to be as large as possible. This is why the government specifies a maximum brake pedal force in their tests with the throttle closed.

Not all drivers can apply the same brake pedal force as an athletic 6’2” male driver who can use the seat back for additional leverage. In particular, older drivers, smaller drivers, and female drivers may find it difficult to get these same results because they can’t press the brake pedal as hard as one of these test drivers. These are precisely the type of drivers that are found most often in sudden acceleration incidents.

 

[wk057]

This is misleading for multiple reasons.

First, this document is about ICE vehicles at speed at wide open throttle while also applying braking to determine stopping distance differences. That's not ever what's been claimed to be the issue with these "sudden acceleration" events in Teslas. These claims always happen when the driver is nearing the completion of a low speed maneuver of some kind (like coming to a stop somewhere, behind another vehicle, parking spot, etc) and "suddenly" the car just goes crazy and accelerates out of control... it's just claimed to be a coincidence that this happens at the exact moment the driver claims to be applying force to the brake pedal. So, this document isn't helpful in comparing here.

Additionally, this document is working with vehicles with vacuum assisted braking. Tesla's brake system can achieve over 2500 Nm of braking capability (well beyond the capability of the motors) with nearly zero effort compared to vacuum assisted systems (yes, I'm aware pre-October 2014 Tesla Model S's have vacuum assisted braking). The Tesla vehicles people are wrecking from pedal misapplication aren't old school vacuum assist systems, they're electromechanical. If you can't get sufficient braking force with these systems you really should not be behind the wheel of a vehicle. Period.

I have a project in the works that involves fully controlling these systems (gonna put Tesla FSD to shame...), and part of it involved matching braking action with effective negative torque achieved. Turns out a pretty light press of the pedal can easily achieve upwards of 1000 Nm, with a panic braking reaching 10000+ Nm of effective braking torque. Even the P100D has ~900 Nm of torque... so literally anyone who can safely operate a vehicle can apply sufficient pressure on the brake pedal to prevent the motors from moving the vehicle, even on the highest performance models, let alone non-performance units.

On the bench I can hold the brake pedal pretty lightly with one hand reached into the car, with no leverage whatsoever (can't imagine this being more than a few lbs of force), and enough braking is achieved to prevent the motors from breaking loose. In fact, the drive units detect that they're "stuck" and error out after moments.

Also keep in mind that while these drive units can produce a lot of their torque at 0 RPM, they can not reach maximum at a standstill... so even less possible to overpower brakes.

So, again, claiming things like the car "jumped forward with my foot mashed on the brake" is absolute nonsense.

Oh, and all of this is assuming that somehow the motors actually did go to full power magically all by themselves.... which is also impossible in itself (see my other posts on the subject for details).

 

[Dan D.]

This is misleading for multiple reasons.
...
On the bench I can hold the brake pedal pretty lightly with one hand reached into the car, with no leverage whatsoever (can't imagine this being more than a few lbs of force), and enough braking is achieved to prevent the motors from breaking loose.

I have no doubt you know what you are talking about WRT Tesla braking systems.

You say holding your hand on the brake pedal with a few pounds of force can prevent the car from moving. If you say so, I haven't tried it. Are you claiming that a few pounds of force on the brake pedal will prevent movement under full power application? That's certainly not true of ICE cars.

Regardless, there are no absolutes. Software bugs, electrical faults, brake/mechanical defect, whatever. Unlikely things happen. Sometimes a one in a million chance happens. If OP isn't posting FUD and actually contacts Tesla and files a complaint with the NHTSA maybe we'll find out if this situation was real. I agree it sounds quite fantastic and I'm very skeptical of the description of ramming, reversing, and ramming.

 

[Gadget-X]

I wish the OP would reply here again. I have a 2020 Performance. It once jumped forward when I was slowly pulling into our garage but the brake stopped it quick as I could push it. The vehicle also beeps loudly when I 2 foot drive it and he did not mention a beep.

Could it be that the OPs car really jumped twice and the first bump bounced back some and the vehicle in front bumped forward some from the bump and jumped forward again. Since I have experienced this jump in our MSP, IMHO the only really improbable part of the story (to me) is the shift to reverse to back up to jump forward again. Also was he in FSD at the time?

Standing by for more info from OP.


M

 

[Rajainmiami]

I appreciate everyone’s input. I honestly cannot tell you if my foot was pressing hard on the brake or if it was just lightly placed. I do not remember really. All I know is I was stopped in traffic and suddenly the car jumped and hit the car in front of me. I agree maybe I unintentionally pressed the pedal but how would it happen twice? I confirmed with the car in front me and he tells me yes I hit him twice !!! I am not trying to blame Tesla and fortunately the damage was minimal and no one was hurt. I am just nervous and now will be paying a lot more attention while stopped in traffic to make sure I am pressing the brakes with force. I still love my Tesla and think it is an amazing car.