Got a sudden accelleration, but totally explained and no damage

Got a sudden accelleration, but totally explained and no damage

Was pulling my Model 3 into a parking spot the other day. Drove part way in then shifted into reverse as there wasn't enough space to turn in at an angle. Then shifted into drive. But the car didn't shift immediately into drive for some reason, so I shifted into drive again. The car interpreted this as a double tap to engage autosteer/cruise, so in retrospect my shifts weren't enough oomph to get past the soft tap and into the hard tap.

Car surged forward, attempting to reach the speed limit of the road 300' away. I stomped on the brake, the car stopped.

I do think Tesla should do some work to refuse auto-drive engagement in a parking lot. Maybe a touch-screen confirmation, because I can imagine cases where you'd want it (following a car out of the lot, for example) but as it is the car is way too willing to pop into auto-drive and scream off in some vector.

lessrandom | 21. tammikuu 2020

... so? Are you saying my account is inaccurate? In my case the sudden acceleration was commanded, but it was an erroneous command that within the context of the sequence of events made complete sense to me at the time. Retaining this behavior is going to just result in more people doing this. The UI needs a change, maybe even a small change, but a change nonetheless.

TabascoGuy | 21. tammikuu 2020

No I am not debunking your claim but it seems Tesla is.

"We investigate every single incident where the driver alleges to us that their vehicle accelerated contrary to their input, and in every case where we had the vehicle’s data, we confirmed that the car operated as designed. In other words, the car accelerates if, and only if, the driver told it to do so, and it slows or stops when the driver applies the brake."

If you feel that your experience is different then you should contact Tesla directly, they won't respond here.

EVRider | 21. tammikuu 2020

@TabascoGuy: The OP admitted it was a user error, by accidentally engaging TACC/Autosteer. | 21. tammikuu 2020

@TabascoGuy - It wasn't a UA event, but the OP admitted it was user error. Perhaps the UI could be better but it seems very few owners make this mistake. Not sure how it could be improved, other than to require a secondary button to engage AP - something I expect most owners who understand the controls would hate. Perhaps it could be an option for those that accidentally trip AP. Select AP with the stalk, then press a confirmation button on the display. Sort of doubtful Tesla will change the interface for one or two people though. | 21. tammikuu 2020

@EVRider - you're just too fast :)

lessrandom | 21. tammikuu 2020

If the UI is retained, with the shifting into drive needing to push past the soft-push that indicates a cruise engagement, I don't see how users can avoid this problem. One day you are tired and don't push as hard because it's been a long day of demolishing a kitchen or something, you're just not going to go all the way to drive. And if the car's reaction is to start accelerating regardless of where you are, now the driver has to quickly regain control from an action they didn't intend to command. If the driver misses the brake and hits the accelerator, which is entirely reasonable in a situation where the driver is already flustered, then whammo, SUA.

I like the quickness of engaging autosteer and cruise on the highway, but this is just not good.

jordanrichard | 21. tammikuu 2020

People need to remember that the naysayers have in the past used what is written here, as fodder for their FUD agenda. So if the OP admitted it was user error, then don’t title a thread as if there was an issue with car. Details like,”.... it was my fault” won’t be part of the headline that will make it’s way to outfits like Seeking Alpha. What will make it would be something like, “....Tesla says there is no issues but their owners continues to recount stories of unintended acceleration”.

lessrandom | 21. tammikuu 2020

There is an issue with the car. The issue is that the UI makes engaging AP the same motion as engaging Drive, and if someone is tired that day they AP instead of D. That wouldn't be bad on its own except that the car goes into hyperdrive if you engage it at the wrong time.

I really like my Tesla. It's an awesome machine. I want Tesla to succeed, and frankly they don't need my help. They're doing just fine succeeding on their own. But if we hide issues and put the kid gloves on we're ultimately not doing Tesla any favors. So I think that talking openly about flaws, especially fixable flaws, is the right thing to do. If someone on the street asks me about my Tesla I tell them I think it's an awesome, brilliant car with a quirky but clearly talented engineering company behind it.

The title of the thread is accurate. The car did accelerate suddenly, and my foot was not on the accelerator. Situations where the car does as it is programmed to do and that leads to surprising results are worth talking about.

Shesmyne2 | 21. tammikuu 2020

I’m a bit unclear-you have to be going a certain speed to employ TACC.
So if you’re in a parking spot & the road is 300’ away...?

Still Grinning ;-)

lessrandom | 21. tammikuu 2020

It engaged. What can I say? The parking spot looks like a lane to the car. You can engage AP from a full stop. Go try it out.

lessrandom | 21. tammikuu 2020

Specifically I drive in hold mode. Thus at least in my M3 I can be at a full stop without my foot on the brake and engage AP. It will engage.

andy.connor.e | 22. tammikuu 2020

It engaged? Whos getting married?

Harriscott | 22. tammikuu 2020

Stop at mailbox at the entrance of a long driveway. Regardless of hold mode I'm still in Drive, but mistakenly press down on the stalk because habit. When I get going the car slowly speeds up (limit 10mph in my case) and I wonder what the heck is happening. Plenty of time, no big deal, and I understand it now. But in tighter quarters I might panic and step on the wrong pedal, and there would be a problem. And if I didn't know (or didn't want to know) that I had stepped on the wrong pedal, then I'd claim the car accelerated out of control. Which is what people generally mean by "UA"

Can I marry my Tesla? I should look into that.

TabascoGuy | 22. tammikuu 2020

EV, TT, and OP, My point was more that "the car accelerates if, and only if, the driver told it to do so". Not so much the "unintended" part.

It sounds to me that the car did what it was told to do and I agree with TT, I'm not sure how Tesla could improve the controls without making it more difficult for everyone else.

blue adept | 22. tammikuu 2020


>>> "There is an issue with the car." <<<

I'm with @TeslaTap and @TabascoGuy on this one since, from what I've read here and your own admission, it sounds to me like the "issue" is one of 'user error' wherein you're not operating your car properly as opposed to the car, itself, not operating properly...

Perhaps YOU should, besides accepting agency for the necessary awareness required for the operation of any vehicle, invest a bit more of YOUR time in familiarizing YOURSELF with the operation of the car's functionality instead of deflecting blame for YOUR own oversight onto the car for doing only what YOU're telling it to do to avoid having to acknowledge responsibility for YOUR own actions?

Just saying.

PrescottRichard | 22. tammikuu 2020

Just helped someone figure out why her car was accelerating to 90 on a certain part of an interstate- TACC was set to 30 MPH RELATIVE. Most of what she drove on was prolly limited to 5 over and then she would hit spots where there wasn’t a limit set by GPS location.

That’s one down.

blue adept | 22. tammikuu 2020

Yes, I take a pretty hard line when addressing those who're trying to talk sh!t about Tesla's functionality (or just Tesla in general), but you cannot expect automakers to hold your hand for you as it is your responsibility to operate your vehicle properly and your fault for the repercussions if you do not...

It's part of the responsibility that comes with what is known as "adulting".

blue adept | 22. tammikuu 2020


Excellent point and apt justification for why such BS should be squashed in no uncertain terms.


r3hxn | 23. tammikuu 2020

Actually I had a similar experience in my ICE, the cruise control if accidentlly tripped from stationary in the wrong setting would accellarate to match speed.

andy.connor.e | 23. tammikuu 2020

Not possible. Activating cruise control locks the speed setting to your current speed. If you're not moving, i think you can figure out the rest.

jordanrichard | 23. tammikuu 2020

I am sure that when basic cruise control came out, there were a number of accidents/incidents related to people learning how to use it. Now, even ones toaster has cruise control and no one gives it a second thought on how to use it.

andy.connor.e | 23. tammikuu 2020

Correct. Someone in a camper engaged cruise control and went back to make coffee because he thought cruise control was going to drive the car.

lessrandom | 23. tammikuu 2020

@blue adept: Yes, of course it is my responsibility to understand how to drive the car. I am also a pilot and I learned how to fly an airplane. Does that mean I never make mistakes? No. Should I hold myself to the same standard of health and fitness that I (and the govt) hold myself to in order to fly an airplane? No, that would reduce the utility of my car beyond acceptable limits. Should we be trained to drive a Tesla like we are trained to fly an airplane, with many hours of dual instruction, performance demonstration gates, and a sign-off before being allowed to drive solo? I personally don't think so, and obviously the car companies (all of them) are going to agree. This is why cars are expected to have usability that tends towards fail-safe.

Tesla seems to agree. The car refuses to engage "Park" while driving on the freeway. What a good idea that is too, because my last car used the button on the end of the right stalk to engage cruise control. Old habits die hard, and in my first weeks of using my Tesla I certainly did that out of habit, a couple of times. Tesla chose to put "Park" on a button, rather than a shifter position like everyone else. It is thus their responsibility to ensure the car carries out that action when it is actually safe to do so, which is the burden they must carry for producing a car with unusual controls.

In general Tesla has done a great job of this. I can, and have, put a half dozen friends of mine behind the wheel of the Tesla and allowed them to drive it with about 10 minutes of instruction. This is a good feature of the Tesla.

Did I drive out of the Tesla dealer flawlessly knowing all possible controls? No. In fact I didn't even know how to reliably shift into neutral until a good two weeks later. Perhaps you are quite a lot more perfect than I, certainly there's plenty of room for that to be the case. But I am betting that nobody here drove out of the delivery center with a flawless operational understanding of their Tesla.

blue adept | 23. tammikuu 2020


Every once in a while we get someone like you in here who's only interested in fabricating some bit of innuendo or spreading misinformation as a means of generating or manufacturing the perception of a fault in Tesla's vehicle design or functionality.

However, the simple fact of the matter is that while Tesla automobiles might be the most technologically advanced, intricately engineered vehicles on the road today (and likely for the foreseeable future as well), they were specifically designed to be easy to operate (like, elementary school level easy to operate) with safeguards built into their operating systems to guard against user oversight to protect the driver from, well, themselves, all to make the transition to EV's just that much more natural and effortless.

The point is that no intensive "training" or "instruction" is required to operate a Tesla effectively and safely as pretty much anyone can jump into one and be on their way with very limited direction, as has been demonstrated time and time again by every Tesla owner out there on the road today.

blue adept | 23. tammikuu 2020


Much the same is the case in the matter of most, if not all, of the incidents involving Tesla vehicles having been proven to be the result of 'user error' &/or driver fault and not any aspect of the car's operation.

To that end there is, at some point, a time when an owner needs to assume responsibility for the safe operation of their car by investing the time required to better acquaint themselves with the particulars of the vehicle's operation which they can do by making use of the readily available materials that are there for just that purpose, to wit:

Lastly, ultimately it doesn't matter whatever bit of fake news or red herrings you or anyone else might want to concoct about Tesla or their vehicles as they'll (Tesla) always know the truth after all has been said and done, as will the rest of the world, leaving all of the naysayers and FUD'sters looking like the idiotic liars they are.

lessrandom | 24. tammikuu 2020

Alright, beating this horse just a little bit more...

If I were to refer to the M3 stalk itself for guidance, I would see the label “R/N/D/Cruise”. However that does not match the actual operation, which is “R/CruiseCancel/Cruise/D” with a 2s hold for neutral.

So the printing on the car itself guides the user to the wrong conclusion. Can we at least admit that is wrong?

jstimpy | 25. tammikuu 2020

I have an MS which has a separate stalk for controlling AP, but based on the description on how it works in the M3 I'm inclined to agree with the OP.

My experience is that autosteer will not engage unless certain criteria is met, such as it must be able to detect lanes markings. As such the car should be able to detect situationally whether or not to allow you to engage AP, i.e. when pulling into a parking spot. A change such as this doesn't have to make the feature any less convenient to use in other situations. I understand that other auto makers don't have these features on their cruse control, but I choose to buy a Tesla because I think they are better than other auto makers.

For context, I am a software engineer for one of the top tech companies and I'm always trying to make my user experience better and sometimes we have to protect the customer from themselves. That's how you become a Trillion dollar company.

Yodrak. | 25. tammikuu 2020

"I have an MS which has a separate stalk for controlling AP, but based on the description on how it works in the M3 I'm inclined to agree with the OP."

I'm thinking the same. From the sound of it, it would seem to be too easy to make a mistake. A mistake even easier than going for the brake and hitting the accelerator - at least those two functions are on separate pedals.

Bob.Calvo | 25. tammikuu 2020

It’s counterproductive when an owner identifies a less than perfect design implementation that could be improved upon but gets dumped on for fear of comments being intentionally misconstrued by the media. I’ve been on and off this forum for seven or more years now. While there is plenty of ill informed FUD to contend with in the media, this site only allows postings by owners with actual experience using the cars. We all want our Teslas to get better with OTA Updates. Lessrandom’s observations have validity. He recognized that it works “as designed”, but that it could still cause an unintended action based on the design choices that have a stalk doing something very different when double tapped. People can be tired or distracted and make a mistake. We’re human. So are the software designers whose code can be improved upon.

Better than every other car? Of course. No contest, but I’d still like an off setting on the Model 3 windshield wipers because that neural net isn’t as smart as it thinks it is and you can’t teach it to turn off when there is no so button.

As stated by Yodrak, I prefer the setup of my S to my 3 on this point.

Bob.Calvo | 25. tammikuu 2020

No off button

Bob.Calvo | 25. tammikuu 2020

No off button

Bob.Calvo | 25. tammikuu 2020


kingpeter.cazeau | 25. tammikuu 2020

Will you pay someone to pick up your Tesla and drop it at a service center?

blue adept | 26. tammikuu 2020


The instructions for stalk operation are pretty well outlined in the Owner's Manual beginning on page 52 and addressed again beginning on page 75 for different functionality, all of which does directly correlate with the "printing on the car itself", so I am still seeing this as only an issue of 'user error' which should be remedied with repetition to achieve the rather shallow learning curve associated with adapting one's self to EV operation from that of ICE.

Honestly you cannot expect the car to do literally every damn little thing for you (we're not quite there yet), much the same as no car has ever been able to, some responsibility is required of the driver themselves (for the time being anyway).

Hang in there, you'll catch on eventually...You figured out how to fly a plane and you'll figure the safe operation of your Model 3 out, too.

blue adept | 26. tammikuu 2020


Full disclosure?

I'm not a Model 3 owner either but I understand that it is required of me to be responsible and fit and aware enough to operate a vehicle safely before I engage in such behavior as the automaker is unable to hold your hand and do it all for you.

Instead, it is expected of all of us to assume some agency for ourselves, you know, that whole 'adulting' thing I mentioned earlier.

Or you can be like this guy:

Your choice.

blue adept | 26. tammikuu 2020


>>> "From the sound of it...." <<<

Well, that's the whole point of these spurious FUD'ster claims, isn't it? There's just enough rationality/reason laced into their fabrications for them to "sound" truthful so they'll gain traction in the public's perception.

Thing is Tesla's happen to have embedded failsafe protocol that prevents the enabling of conflicting functions, causing them to cancel one another out to avoid systemic/functionality interruption...

An actual Tesla owner who had the occasion to encounter such a conflict would've been aware of this.

blue adept | 26. tammikuu 2020


>>> "...this site only allows postings by owners with actual experience using the cars. <<<

This is emphatically incorrect based on, literally, everyone's experience with this site.

>>> "...doing something very different when double tapped." <<<

Zombieland Rule #2: The Double Tap – Never assume a zombie is dead. Always make sure with a clean shot to the brain.

Other than that, see above replies to previous posters for further commentary on this matter.

blue adept | 26. tammikuu 2020

Dead horse is dead, beaten or otherwise.