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Urgent Collision Avoidance Warning

Discussion in 'Prius v Main Forum' started by Otty, Mar 16, 2016.

  1. Otty

    Otty New Member

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    Today I was on a highway traveling at 60 miles an hour. There were no cars in front or on either side and nothing on the road. My foot was on the accelerator and not on the brake. Suddenly the seat belts pulled very tight (I believe that is called "pre-tensioning") and the brakes slammed on without any input from me. The car rapidly decelerated to about 30 miles an hour. Fortunately there was nobody tailgating me. After that everything seemed OK. My vehicle is a 2013 Prius v (lowercase v for the Prius v wagon) model 5 which has the technology package.

    I took the car to the dealer and they checked the collision avoidance system and said they could not find a problem. The service manager said he has a Camry and it has happened to him once. They had never heard of it happening on a Prius. Apparently Toyota has a bulletin about this for the Camry, but not the Prius. They suggested I turn off the Collision Avoidance System with a switch that is under the dash.

    I am not sure whether to turn it off because if I do I lose the adaptive cruise control and collision avoidance, two features that I paid $5,000 extra for and could save my life. If I leave it on this can happen again possibly causing an accident.

    I have done the following:

    1. Notified the NHTSA to file a safety complaint about the vehicle.
    2. Filed a complaint with Toyota, demanding that I get a loaner car until this can be fixed.
    3. Notified our local television station consumer investigation reporter.
     
  2. wjtracy

    wjtracy Senior Member

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    You should call Toyota USA and give them a chance to solve the problem for you. Immediately calling the TV station or anyone else sounds like you have a grudge or fake troll post here.
     
  3. Otty

    Otty New Member

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    I did call Toyota, my intention in notifying the news (if they even do a story is to let owners know about the potential problem. I have know idea what you mean by a fake troll post.
     
  4. wjtracy

    wjtracy Senior Member

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    #4 wjtracy, Mar 16, 2016
    Last edited: Mar 16, 2016
  5. bisco

    bisco cookie crumbler

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    this is what scares me about autonomous cars.
     
  6. rdgrimes

    rdgrimes Senior Member

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    This might just be a slight over-reaction? It happened one time, and there's a good possibility that there was something in or near the road that triggered it. For all we know, the system DID save your butt and you completely missed seeing it. Metal plates in the road, overpasses, any number of things might generate a response. If it happens more than once in dis-similar situations, then you have a gripe.
     
  7. Air_Boss

    Air_Boss Senior Member

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    Surprising the data recorder doesn't capture codes for (reason for) CAS activation.
     
  8. rdgrimes

    rdgrimes Senior Member

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    It does.
     
  9. DonDNH

    DonDNH Senior Member

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    Such an activation of the CAS used to happen to me periodically in the same spot on my commute. There is a stretch of road on a divided highway that is slightly uphill and slightly curving to the right. At the crest of the hill the road turns more sharply to the right. There is a highway sign on the opposite side of the road that I believe is reflecting my radar causing it to believe I am closing too fast on a impediment in my lane and activating the collision avoidance. It only seems to happen in this spot and only if I'm in the fast lane with the DRCC set to maximum distance.
     
  10. wjtracy

    wjtracy Senior Member

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    Toyota Prius v Owners Sue Over Flawed Pre-Collision System

    In this case above, I think the beef was that the early Toyota v system did not qualify for the IIHS standards (not well designed to stop the car). These articles about Prius v go back to 2013...gotta assume Toyota has made changes since then. In one article I saw, Toyota USA argued at the time (~2012) there were no IIHS standards for what collision avoidance should do. Apparently there are now IIHS standards and I must assume the newer model years incorporate that.

    In industry sometimes 2 out of 3 voting of (temperature) readings is used for emergency action, but you'd need 3 sensors. The reason is you never know if a reading goes bad due to sensor failure, so you want two opinions.
     
    #10 wjtracy, Mar 17, 2016
    Last edited: Mar 17, 2016
  11. Air_Boss

    Air_Boss Senior Member

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    So did Toyota offer to read it?

    Note that NHTSA and IIHS are, as of today, demanding, and 14 manufacturers agreeing to industry-wide CAS adoption by 2022 for light-duty vehicles.

    I anticipate accordion-like multiple MVAs when these things trigger arbitrarily, with trucks (no CAS required) adding to the carnage.

    Classic case of 'Be careful what you ask for'.
     
  12. rdgrimes

    rdgrimes Senior Member

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    Its not clear to me just what the 2013 systems do record. My '16 Rav4 records everything, including cameras. But its also not clear if it records everything all the time or just some things in specific circumstances. My guess is that it records those things that Toyota deems might reasonably protect THEM in a law suit.
     
  13. Air_Boss

    Air_Boss Senior Member

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    No doubt, which likely explains their disinterest in reading an isolated unintended CAS activation.
     
  14. rdgrimes

    rdgrimes Senior Member

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    Here's where a decent quality dash cam might be useful. Such things have GPS, recording speed, location, HD video, etc.
     
  15. Air_Boss

    Air_Boss Senior Member

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    Just add a CAS activation indicator and brake system pressure trace, and ... voila!
     
  16. rdgrimes

    rdgrimes Senior Member

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    Well they record audio, which would include beeping things.
     
  17. Air_Boss

    Air_Boss Senior Member

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    Audio, beeping, "What is it doing now?", "Why is it doing that?" and some other four-letter epithets.
     
  18. Offline

    Offline Active Member

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    There is a long list in your owners manual of what can cause the automatic braking system to malfunction.

    There has never had the automatic braking system malfunction on the 2012 Prius v Five/ATP we bought new in 2012 (22,000 miles driven) but the automatic braking system on our 2014 Sienna Limited/ATP has malfunctioned on maybe ten occasions in 30,000 miles since we bought it new.

    By "occasions" I mean that, when it happens, the malfunction usually occurs every time cruise control is engaged - over and over - until the engine is restarted or the vehicle has been driven several miles. The driver seat belt has never tightened during one of these malfunctions - only the brakes are slammed on. So far, there has been only one close call when a car following too closely almost "ate my bumper".

    Each time Pre-Collision intervened on the Sienna it was for a very good reason and it prevented a crash on one occasion when a car in a slower moving lane swerved into my lane while I was going around 60 mph.

    The auto braking problems on the Sienna usually happen after a hard sweeping turn or after going over a bump. If fact, the problem started happening on separate days after driving over the same railroad tracks at about 45 mph. And I finally realized that the problems have occurred only on warm days - temperature over about 90 degrees.

    I've tried driving to a Toyota dealership several times when the problem was occurring over and over but the problem always "fixed itself" before I could get to a dealership.

    I have been told that there has been no evidence of the problems stored in our Sienna's event and code recorders. A Toyota dealer has attempted to recreate the problem on several visits to the dealership but has never been able to do so. I hope to work with a Toyota dealer this summer to figure this out. My guess is that the problem has something to do with VDIM since it can control the ECB. VDIM is "Vehicle Dynamics Integrated Management" which is included in the ATP on the Sienna but not on the Prius v. ECB is "Electronically Controlled Brake".

    Regardless of these issues, I still value this technology highly and will never buy another vehicle without it.
     
    #18 Offline, Mar 19, 2016
    Last edited: Mar 20, 2016
  19. Air_Boss

    Air_Boss Senior Member

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    By that National Sample of One statistics set, uncommanded braking (on the Sienna) seems likely to cause more problems than it is designed to solve.
     
  20. wjtracy

    wjtracy Senior Member

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    NHTSA must be getting a lot of false-positive reports...