Sudden Unintended Acceleration

[Big Earl]

@Ying do you typically turn on your turn signal when pulling into your parking spot? I’m wondering if you went to cancel the turn signal and accidentally grabbed the cruise control stalk instead. I noticed in one of your pictures it appears the turn signal was on.

 

[pdxgibby]

Oh yeah -- the 18 mph minimum. Who else finds it interesting that Tesla reported to the OP that there was 18% accelerator press. Maybe what Tesla said was that the car was accelerated to 18mph and the OP misunderstood. The odds of those two numbers matching are very small, from a statistical probability.

I bet he hit the cruise control stalk up accidentally and the car took off en route to 18mph. This leads him to believe that the car accelerated without him pressing the accelerator pedal -- which is technically true.

 

[pdxgibby]

@Ying do you typically turn on your turn signal when pulling into your parking spot? I’m wondering if you went to cancel the turn signal and accidentally grabbed the cruise control stalk instead. I noticed in one of your pictures it appears the turn signal was on.

And a right turn signal into a parking spot would be an upward motion on the cruise control stalk. It's all adding up for me now.

 

[iwannam3]

I had an unintended acceleration incident years ago. As I pulled into a parking spot simultaneously cars on both sides backed out. I panicked as I felt I was acceleration towards building even though I was stopped and I pressed the brake so hard it blew the right front brake hose!

 

[Shateam]

And a right turn signal into a parking spot would be an upward motion on the cruise control stalk. It's all adding up for me now.

But wouldn't activating TACC have shown up in the logs? You would think Tesla would shared that bit of info with the OP?

 

[pdxgibby]

But wouldn't activating TACC have shown up in the logs? You would think Tesla would shared that bit of info with the OP?

I would think that nugget of information would be helpful. Maybe thats exactly what Tesla told him, but the OP heard something different. Regardless, this seems the most likely explanation.

 

[SMAlset]

If I'm not mistaken and remember what Ying described of his communication with Tesla, they looked at his logs and said it was due to him depressing the accelerator for a second and then the brake -- during which time he had already traveled over the curb and into the landscape and hitting part of the building -- so they said it was driver error. So all the discussion about other explanations I think is moot. It's just Ying doesn't believe he did that and so here we are.

I can say that as I'm pulling slowly into a spot where I know there's a curb to contend with, I tend to pull in slowly and then will try to move my way forward thinking in my mind how close am I coming to the curb, so touching the accelerator to get closer before braking completely and putting in park. The other day I was backing the car in our driveway up to near the garage door to charge the car outside. The driveway is on an incline going up to the house. For some reason, maybe I wasn't using my profile but my husband's, I was having some trouble backing up close enough to the door but not too close and got kind of nervous after an attempt that left me too far away in my mind. The car started moving forward and I needed to apply the accelerator to go in reverse and it did move faster than I expected. Didn't hit the garage door or anything but kind of decided to park it where it was since the cord would reach at that point, but just saying sometimes you can get surprised at the acceleration.

 

[pdxgibby]

All good points. I’m just theorizing how this could have happened where both sides are technically correct.

 

[DrivingRockies]

blew the right front brake hose!

That should never happen.

 

[dennis_d]

I can help to pull the log out of the car for independent investigation since I located near by, but as @wk057 said in most cases it's a driver's error.

 

[dennis_d]

I think solution for this kind of problem would be the ability to enable "chill mode" by GPS coordinate, similar to "smart suspension" , where we can enable chill mode at home or at work at least.

 

[alevek]

My guess is that the car was against the curb without the OP realizing it. To make it move OP slowly applied accelerator. At 18% car jumped the curb and "unintentionally accelerated" into the wall.

 

[pdxgibby]

As @Ying said, he’s now pursuing legal action, I’m sure he won’t be giving any updates. This one will likely fall into the “we’ll never know” category.

 

[wk057]

If Tesla said the accelerator was pressed to 18%, that would rule out cruise control related acceleration. The logs don't show cruise-initiated acceleration as a pedal percentage. The logs directly reflect the physical pedal's hall effect sensor outputs.

If you resume cruise, without touching the accelerator, the logs will show 0% even while the car accelerates due to cruise resume (which has its own logged variables).

Also, if the driver was in fact pressing the brake like they should have been in this situation, cruise control wouldn't be possible to enable anyway.

 

[AnxietyRanger]

This here is where Tesla proving the actual logs would help in any case. A verbal explanation alone can be more easily misunderstood and misreported onwards.

I agree it is a curious co-incidence that the number happened to be 18%, the same as the cruise speed limit of 18 mph. But of course it may be just a co-incidence. (It did not originally occur to me to look at this number, since the equivalent number in kph is different, 30.)

Also, if the driver was in fact pressing the brake like they should have been in this situation, cruise control wouldn't be possible to enable anyway.

If the driver was slowing down by regen (very common, yes?), enabling cruise certainly can result in feeling symptoms similar to SUA. I don't know if this happened in @Ying's case, but it has IMO happened in TMC reported cases in general.

 

[dennis_d]

Tesla does some really verbose logging, it's going to really hard to proof anything in court

 

[AnxietyRanger]

But wouldn't activating TACC have shown up in the logs? You would think Tesla would shared that bit of info with the OP?

Yes, as @wk057 and common sense says, it most certainly would show in the logs.

Unfortunately since Tesla refuses to share the logs, we don't know what they actually said - and we don't know what the process of Tesla's service center personnel finding out is, i.e did the service center advisor say it correctly.

Was the person informing @Ying someone who had read the logs him/herself? Or were they too repeating a summary or explanation coming from someone else? Latter being more prone to the "broken telephone" effect of misrepeating?

18 mph turning into 18% by misreading or mishearing at some point in such a process could happen. Not saying it did, just noting that certainly it doesn't sound impossible given the co-incidence with the number.

That's one reason why the log excerpt would be so useful to have.

 

[AnxietyRanger]

Tesla does some really verbose logging, it's going to really hard to proof anything in court

I believe the main motivation for OP at this stage is to get the logs in the first place, since Tesla is refusing to share.

I am actually thinking had Tesla just shared the logs, the OP might never have even posted here or allegedly started the legal action... Transparency is good sometimes. Especially given that almost none of us believe actual SUA is anything but a user error anyway.

 

[cwerdna]

I think the vast majority of non-manual transmission cars only use the right foot when driving.

Agreed. I've never ever seen anyone drive a non-manual where they used their left foot to brake except in some very rare instances (e.g. to prevent rollback on a hill).

I remember there was some thread here on TMC where people were arguing about the "merits" of driving an automatic w/two feet (left foot braking, right foot accelerating). Two foot driving I don't think was it.

Until I saw the debate thread, it hardly registered for me that there are actual people who do that. I suspect the reaction from most automatic drivers is of bewilderment and shaking their head, which I've witnessed.

I'll never forget the first time I accidentally raised the cruise control stalk instead of the blinker. The Model X accelerated towards 18 mph in a parking structure. A quick press of the brake halted the action. The newer Model S does the same when I accidentally raise or lower the cruise stalk. Why Tesla insists on activation with an up/down motion is nonsense. The cruise stalk should only activate upon a pull motion. Let the raise and lower action change the set cruise speed anytime, just don't turn it on if it is off.

On this note, I think i've posted about this several times. Some automakers (e.g. Nissan) won't even let you resume (CC) unless your speed is above 25 mph.

And, IIRC, the behavior on Toyotas (e.g. my 06 Prius) is even more conservative/annoying. If you drop below 25 mph, the cruise control intentionally forgets the set speed, so resume won't work anyway.

If Tesla implemented these, it seems that could prevent some of these incidents.

 

[brkaus]

Cruise lever up/down does nothing for me except lock on current speed.