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"Obstacle detected" - blocking acceleration - very dangerous!

I just had something very scary and dangerous happen less than two hours ago that hopefully never occurs again. I live in San Francisco and I was visiting a storage facility on Treasure Island. I was returning to San Francisco by merging via a stop sign directly on to I-80 West. For people who know this freeway entrance, it is very abrupt and you need to go from 0-60mph very quickly to merge into oncoming traffic that is coming out of the Yerba Buena Island tunnel. This of course is no problem for the P90DL, or a number of other cars I have driven on this route before.

So I see a more than adequate opening between cars coming up, wait for the first car to pass, and then step on the accelerator from my dead stop. For a fraction of a second the car begins to accelerate, and then nothing. I step on the gas several more times very quickly as the car has now rolled out into the lane with a car closing on me at 60+ mph, and still nothing happens. I hear a warning sound and look down at the console and there is a warning symbol and it is telling me that there is an "obstacle detected", and I can see that the right front corner sensor is at the whitish yellow level - which is not even close to anything by San Francisco driving and road width standards.

The second car swerves to the next lane over and whizzes by me. After a couple of seconds the accelerator seems to work again and I am able to drive away.

This car disabling the accelerator because it thought it might be close to something has to be one of the worst and most unsafe UI choices I have ever seen. I could have easily been rear ended as well as injured the driver behind me. I would much rather have the car let me drive into it's imaginary wall than ignore my inputs at such a critical moment.

I called support and Tesla has the logs now, so hopefully they can get to the bottom of what happened. Otherwise, everything seems normal about the car, but I may have some trust issues with it for a while...
 
Reading your description of the issue and the warning message suggests to me that your right front corner ultrasonic sensor malfunctioned. Have the Burlingame Service Center check it out.

That is certainly possible, and the SC will be following up, but I'm still unclear how this aspect of the vehicle works. If I am not using AP or any other driver assistance functions, should the car be disabling my ability to accelerate based on the sensors? When I pull into a tight garage with objects nearby the sensors go crazy, but it doesn't seem to prevent me from moving in that case. Granted, I am not trying to accelerate quickly though.

When I was stopped at this entrance I don't remember hearing any sensor warnings as if the car thought it was close to something. Assuming they have good log data from this they should be able to figure out what happened. Sensors working or not, I don't like the idea that they can inhibit control of the vehicle. The driver's decisions should override anything else. This seems more dangerous than the problem it is trying to solve.
 
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aesculus

Still Trying to Figure This All Out
May 31, 2015
4,967
2,892
Northern California
This car disabling the accelerator because it thought it might be close to something has to be one of the worst and most unsafe UI choices I have ever seen.
I hope this was not a knee jerk 'upgrade' from that Model X event where the person pushed the wrong pedal and blamed Tesla.
 
I spoke with the service center who has looked at the logs. They are going to look again based on additional information I have given them but all they can say so far was that the car was detecting an impending collision (he couldn't say which sensors were deciding this) and decided to limit torque / acceleration. The only thing I can think of is that the first car which passed by in the lane I was merging into would have just gone by very closely when I hit the accelerator to merge in behind him. I can say with some certainty that I didn't not accelerate until that vehicle was past me but perhaps there is a window of time after the event where you are not allowed to accelerate? It certainly took what seemed like a second or two before I could accelerate again even though nothing was nearby. This is what made the whole thing very dangerous. The car was basically dead out in the lane. Had the car not moved at all I would have been OK (it wouldn't have pulled out). Had the car allowed me to accelerate shortly thereafter I would have been OK too.
 
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MP3Mike

Well-Known Member
Feb 1, 2016
19,857
49,625
Oregon
I hope this was not a knee jerk 'upgrade' from that Model X event where the person pushed the wrong pedal and blamed Tesla.

I agree, this type of situation is exactly what some people were trying to describe in that thread as a reason that the car can't override your accelerator input when it thinks it sees something that you might hit.
 
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MP3Mike

Well-Known Member
Feb 1, 2016
19,857
49,625
Oregon
I spoke with the service center who has looked at the logs. They are going to look again based on additional information I have given them but all they can say so far was that the car was detecting an impending collision (he couldn't say which sensors were deciding this) and decided to limit torque / acceleration. The only thing I can think of is that the first car which passed by in the lane I was merging into would have just gone by very closely when I hit the accelerator to merge in behind him. I can say with some certainty that I didn't not accelerate until that vehicle was past me but perhaps there is a window of time after the event where you are not allowed to accelerate? It certainly took what seemed like a second or two before I could accelerate again even though nothing was nearby. This is what made the whole thing very dangerous. The car was basically dead out in the lane. Had the car not moved at all I would have been OK (it wouldn't have pulled out). Had the car allowed me to accelerate shortly thereafter I would have been OK too.

I hate to say it but if you don't get a satisfactory answer out of Tesla you should report this to the NHTSA, as like you found this could be very dangerous.
 
I've seen the car slow down suddenly on TACC for imaginary objects ahead, which isn't all that good, but refusing to accelerate under manual control sounds seriously dangerous.

That sounds more like the radar saw something than the ultrasonic sensors. I've had it warn me of an imminent collision when there was a car a safe distance ahead on a rise after a dip I was going down into. Since I was already on the brakes, I'm not sure if it would have accelerated if I'd tried.

Please keep us informed.
 
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treasure island on ramp highlighted.PNG
Just in case anyone was unclear on the scenario. Here is the map of where this happened. I would show you the street view, but Google Maps has a very hard time staying on the upper deck of this road and keeps dropping into the lower deck.

Google Maps

My car would be in the position highlighted in yellow, waiting at the stop line to accelerate and merge.
 

Cosmacelf

Well-Known Member
Supporting Member
Mar 6, 2013
10,259
30,828
San Diego
Wow, I gotta say that the odds of getting INTO an accident due to this feature is probably higher than the accident avoidance feature keeping you out of one.

There are a fair number of times where I'm patiently waiting for traffic to break just enough that I can make a 90 degree and floor it to keep up with traffic. Having the car be unresponsive is just a prescription for disaster.

Whenever I get my X back from the repair shop, I think I'll turn off that accident avoidance feature...
 
If you turn off the accident avoidance this will not occur. I had this happen when trying to load my car on a truck carier. I set this to off and it then responded.
I'm not sure which specific feature you are referring to. I do have the "Collision Avoidance Warning" set to "Medium", but only because my understanding was that this is merely a warning and doesn't take any actions. Is that not the case? When speaking with the Tech Support and Service Center about the issue I did inquire if there was a setting whereby I could disable this problem from happening again and they couldn't think of one.
 
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Wow, I gotta say that the odds of getting INTO an accident due to this feature is probably higher than the accident avoidance feature keeping you out of one.

There are a fair number of times where I'm patiently waiting for traffic to break just enough that I can make a 90 degree and floor it to keep up with traffic. Having the car be unresponsive is just a prescription for disaster.

Whenever I get my X back from the repair shop, I think I'll turn off that accident avoidance feature...

Let me tell you, it was a terrible feeling to have happen. As I just mentioned in another post, I'm not sure this is something you can turn off either at present.
 
I'm not sure which specific feature you are referring to. I do have the "Collision Avoidance Warning" set to "Medium", but only because my understanding was that this is merely a warning and doesn't take any actions. Is that not the case? When speaking with the Tech Support and Service Center about the issue I did inquire if there was a setting whereby I could disable this problem from happening again and they couldn't think of one.

That's exactly what I'm referring to and turning it off worked for me.
 
That's exactly what I'm referring to and turning it off worked for me.

I find it strange that they don't mention this in the documentation which seems pretty clear that this was a warning-only system that takes no action. I went through these things while still at the factory lot before driving off the first time because I wanted to make sure the car wasn't going to do anything weird and try to save me from myself in a way that would interfere with my inputs.

I'm trying to understand your car carrier scenario. Was it that you need a certain minimum amount of throttle to get up a ramp and it wouldn't give it to you? I know parking in some of my garage spaces I get within inches of objects and the car freaks out with warnings, but it doesn't prevent movement, although I am only using the smallest of accelerator inputs at that point. Did it actually give the collision warning alert on the dash like I saw (with the triangle alert symbol)?
 
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