temporary runaway car after stop autopilot?

[Alex Liu]

I had good luck this morning on highway, for about 10 seconds I was sitting in a runaway car without anyway to kill it.

I was using autopilot on highway (lane keep and adaptive cruise) and want to take exit, so I gently push gas pedal to maintain speed and push shift lever up, the autopilot indicator disappeared from screen so I take off the gas pedal but surprisingly _NO_ re-gen brake ( I have the maximum re-gen setting ), the car maintain speed as it was. I though it might still in the adaptive cruise mode, so I applied brake. _NO_ brake! the car keeps maintaining speed and closer to the car in front of me. I tried change lane but the gas pedal didn't work either, _NO_ acceleration!

In desperation I re-engage the autopilot by pull lever down, autopilot did engaged and brake again everything backs to normal.

I immediately request Tesla service to download my car log for diagnosis, it seemed a software issue might get me killed this morning. Hope they can find what's wrong and fix it ASAP.

My car is Model 3 built on Dec 2018 with Autopilot no FSD.

 

[ilyak]

so I applied brake. _NO_ brake!

According to the leaked theory of operation document for model 3, the brake pedal is mechanically connected to the tandem master cylinder via a push-through link in the brake booster:

If the vehicle power net fails and the Hydraulic Boost failure Compensation (HBC) is also not available, the iBooster is still able to provide a deceleration through a mechanical push through which provides a direct connection between the pedal and the master cylinder.

So what you are describing isn't really possible, the car cannot simply ignore brake pedal input.

 

[AlanSubie4Life]

gently push gas pedal to maintain speed and push shift lever up

I suspect at this point you shifted to neutral by mistake. You pushed up halfway on the stalk and kept it there for a second. In neutral neither regen nor accelerator would be active.

I applied brake. _NO_ brake!

As mentioned, this is not possible (assuming your brakes now are working correctly - obviously they could have failed completely due to a massive mechanical failure but you'd be seeing warnings and they wouldn't just start working again). Everything else is possible, or at least roughly could have transpired as described. It's fairly common for people to not press the brake hard enough and in a panic situation it could be perceived as not working well enough. But you should have seen a response. (It's possible you were pressing the accelerator instead of the brake, too, though seems unlikely with the rest of your description.)

Let us know when Tesla service confirms that your car was briefly shifted to neutral (and provides you data on other pedal inputs). Would be good to get closure on this (for yourself, mostly).

 

[qdeathstar]

I think the way the neutral shift is done is goofy, and ultimately that’s what appeared to have caused this almost accident. Tesla should just put the nuetral on the screen or perhaps long hold all the way up on the stalk. Putting it in the middle with a small detent is awkward.

 

[Saghost]

As noted above, this sounds very much like an inadvertent shift into Neutral, which will cause everything described except the lack of response to the brake pedal - which is physically impossible without a total dual master hydraulic failure that would produce a bunch of error messages and cannot be recovered by software.

 

[Bill Foster]

Glad the "no" brake claim has already been cleared up lol

 

[ewoodrick]

As noted above, this sounds very much like an inadvertent shift into Neutral, which will cause everything described except the lack of response to the brake pedal - which is physically impossible without a total dual master hydraulic failure that would produce a bunch of error messages and cannot be recovered by software.

Or accidental push on accelerator instead of brake. Not uncommon when panicking.

 

[Flatbat]

OP could have long pressed the end of the RH stalk to get emergency braking as well. Really only useful if the brake pedal had fallen off though!

 

[MorrisonHiker]

1. Teslas don't have gas pedals.
2. Holding in the Park button engages the emergency brake.

 

[whatthe2]

1. Teslas don't have gas pedals.
2. Holding in the Park button engages the emergency brake.

Or do they?


Definition of gas pedal


US
: a pedal in a vehicle that is pressed down to make the vehicle go faster : accelerator

 

[WilliamG]

I'm highly suspicious of this. First, new guy with one post. Never the best sign, BUT hardly unprecedented for a new person to ask for help, so perhaps give the benefit of the doubt.

But..

In desperation I re-engage the autopilot by pull lever down, autopilot did engaged and brake again everything backs to normal.

I find this part very hard to believe. If I'm reading this correctly, guy/girl has a brake mechanical failure which fixed itself when autopilot re-engaged? Yeah. No. I can't buy that.

What IS possible is the person shifted into neutral by mistake, pressed the accelerator (nothing happens, as intended), in a panic pressed the accelerator again thinking it was the brake (still nothing happened). I can't explain this scenario any other way.

 

[EVDRVN]

Yet another driver error thread.

 

[jeeperrs]

10 seconds at 60 mph or greater and they would have been through the intersection and back on an on ramp. The rest of the story may be true but 10 seconds is a very long time at 60 mph or more for most any exit ramp.

 

[Saghost]

OP could have long pressed the end of the RH stalk to get emergency braking as well. Really only useful if the brake pedal had fallen off though!

In fairness, a double circuit hydraulic failure can happen to a car, though the only actual case I've read about involved a lifted pickup where they didn't resize the lines when they raised it - it went over a bump, both front flexible lines overextended and broke, and voila, no brakes. Not likely for a 3, though.

In any case, my point was that since holding the end of the stalk engages the parking brake, it can also bypass failures of the main brakes downstream, rare though they are.

 

[DopeGhoti]

As usual, this sort of thing can be fixed by adjusting the large nut behind the steering wheel

 

[jpfive]

I'm highly suspicious of this. First, new guy with one post. Never the best sign, BUT hardly unprecedented for a new person to ask for help, so perhaps give the benefit of the doubt.

But..

In desperation I re-engage the autopilot by pull lever down, autopilot did engaged and brake again everything backs to normal.

I find this part very hard to believe. If I'm reading this correctly, guy/girl has a brake mechanical failure which fixed itself when autopilot re-engaged? Yeah. No. I can't buy that.

What IS possible is the person shifted into neutral by mistake, pressed the accelerator (nothing happens, as intended), in a panic pressed the accelerator again thinking it was the brake (still nothing happened). I can't explain this scenario any other way.

One post. No responses to those who have replied to post. Let's see if we get a follow up post of Tesla's response to his request for help.

Hey, how 'bout that stock price! Maybe he shorted at 900+. 767 today, so he'd be looking good for the moment.

 

[timp123]

1. Teslas don't have gas pedals.
2. Holding in the Park button engages the emergency brake.

Now I'm curious, what happens if you hold the park button at high speed? I'd like to know, because some cars have a button at this location which activates the windshield washer...so it's conceivable a Tesla novice might play with it inadvertently while driving.
I once tried holding up the e-brake button on my 2016 Civic while doing about 30mph to see what happened, and it actually locked the back wheels. Not trying that again. Would this happen on a Tesla as well? Perhaps someone more adventurous than myself can try and report back?

 

[Runt8]

Now I'm curious, what happens if you hold the park button at high speed? I'd like to know, because some cars have a button at this location which activates the windshield washer...so it's conceivable a Tesla novice might play with it inadvertently while driving.
I once tried holding up the e-brake button on my 2016 Civic while doing about 30mph to see what happened, and it actually locked the back wheels. Not trying that again. Would this happen on a Tesla as well? Perhaps someone more adventurous than myself can try and report back?

It will slowly apply the brakes and bring you to a stop.

 

[Saghost]

It will slowly apply the brakes and bring you to a stop.

While loudly beeping at you and displaying a warning message as I recall.

 

[Garlan Garner]

I had good luck this morning on highway, for about 10 seconds I was sitting in a runaway car without anyway to kill it.

I was using autopilot on highway (lane keep and adaptive cruise) and want to take exit, so I gently push gas pedal to maintain speed and push shift lever up, the autopilot indicator disappeared from screen so I take off the gas pedal but surprisingly _NO_ re-gen brake ( I have the maximum re-gen setting ), the car maintain speed as it was. I though it might still in the adaptive cruise mode, so I applied brake. _NO_ brake! the car keeps maintaining speed and closer to the car in front of me. I tried change lane but the gas pedal didn't work either, _NO_ acceleration!

In desperation I re-engage the autopilot by pull lever down, autopilot did engaged and brake again everything backs to normal.

I immediately request Tesla service to download my car log for diagnosis, it seemed a software issue might get me killed this morning. Hope they can find what's wrong and fix it ASAP.

My car is Model 3 built on Dec 2018 with Autopilot no FSD.

What a way to enter the forum. LOL