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Euro model's AHS Adaptive high beam system

Discussion in 'Prime Main Forum (2017-2022)' started by GT4Prius, Apr 19, 2017.

  1. GT4Prius

    GT4Prius Active Member

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    I really like this feature. Sorry to rub it in for you US folk who don't have it!

    It really works well for me and is very impressive.

    One odd thing though. It refuses to turn on high beam until I hit 40mph. That is not so good in dark windy country lanes where I would go faster if I could see further ahead!

    In other words I can't see well enough in low beam to go fast enough to turn on the high beams!

    I have scoured the manual and it mentions (from memory) that it only and works above 9 mph that it has a configurable change of mode in some unexplained way at a much higher speed 60 or 75 I forget. The point is that nowhere is 40 mph mentioned.

    Any Euro owners got any insight into this?



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    #1 GT4Prius, Apr 19, 2017
    Last edited: Apr 19, 2017
  2. mr88cet

    mr88cet Senior Member

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    Hmmm... "AHS," eh? I know of a portion of Toyota Safety Sense called "AHB" -- Automatic High Beams (i.e., not "AHS," but "AHB") -- that seems to be what you're describing and I'm pretty sure is on the US version. At least, when I dial into Toyota Safety Sense, I get a web page with "Toyota Motor Sales USA" at the bottom that describes this function.

    It says 25MPH minimum. Are you sure the speed threshold for you isn't 40KPH rather than 40MPH?

    iPhone ? Pro
     
  3. GT4Prius

    GT4Prius Active Member

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    No. The manual calls it AHS and it is different from and better than AHB as discussed elsewhere.

    The speed threshold is 40 mph and you will see from my post that this is what I have experienced, not what I have read.

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  4. mr88cet

    mr88cet Senior Member

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    Interesting... Do you know what the differences are, other than 25MPH vs. 40MPH?


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  5. Crowmag Naman

    Crowmag Naman Junior Member

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    Does not sound better to me if you can't see whats in front of you unless you speed up. :(
     
  6. Samprocat

    Samprocat Active Member

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  7. unicorn

    unicorn Member

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    Here is the Automatic/Adaptive high beams explanation: Would it make sense to buy the prime if I never intend to plug in? | Page 2 | PriusChat

    According to EU Manual: "When all of the following conditions are met, the high beams will be turned on automatically and the system will operate:
    1. The vehicle speed is approximately 15 km/h (9 mph) or more (* for turning 19mph or more)
    2. There are no vehicles ahead with headlights or tail lights turned on.
    3. The area ahead of the vehicle is dark."

    So, it should work ... no idea.
    Plus question: Any dazzling effect on the drivers ahead?
     
    #7 unicorn, Apr 19, 2017
    Last edited: Apr 19, 2017
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  8. civicdriver06

    civicdriver06 Active Member

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    Well 40 mph,would only be about 64 kmph .
    Thats not really fast and you should be able to see enough with only the low beam turned on,but if I guess you will allways be able to turn off the system and use high or low beam manually if needed .
    At least you should be able to.
     
  9. GT4Prius

    GT4Prius Active Member

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    No it's NOT on the Prime. The Prime has LED auto high beam. The Euro version has AHS which is much more than that and much better. I don't want to have to keep repeating myself.

    It is an adaptive array high beam that can selectively keep high beam on while not dazzling other drivers who are traveling either in the same or opposite direction, and can also direct light ahead around corners in the direction the car is steering.

    Can any European driver who actually has this advise me if they have any insight into the question I have asked, based on their own experience?

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    #9 GT4Prius, Apr 19, 2017
    Last edited: Apr 19, 2017
  10. civicdriver06

    civicdriver06 Active Member

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    This is supposed to be the system in action,but I guess it hard for the camera to really show off the effectiveness of it.
    Does anybody understand French ?


     
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  11. GT4Prius

    GT4Prius Active Member

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    Phew, thanks for your very helpful post, some knowledge and some restoration of my sanity at last!

    No, no problems at all with dazzling other drivers. Apart from the issue I raised this is very very clever stuff and works very well indeed.

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  12. Lee Jay

    Lee Jay Senior Member

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    Interesting. I've never used the high beams just for being able to see where I'm going, at any speed on any road type (and we have some extremely severe winding roads around here). Low beams are sufficient for that at any speed I've driven (up to over 75mph). I use high beams when there might be animals near to but off the side of the road that I'd like to detect before they decide to run out in front of my car.
     
  13. Trollbait

    Trollbait It's a D&D thing

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    According to this, the system has 3 different patterns.
    [​IMG]
    40mph is probably the limit for that low speed mode, and you are seeing that pattern switch. The low speed pattern could still be high beam when compared to traditional headlights.

    The US Vehicle Code is outdated. We can't get these advanced headlight systems because of that.
    The sooner you see something, the sooner you can react to it. 75mph is likely outrunning the low beams.
     
  14. unicorn

    unicorn Member

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    ... in this case ... Phev :)

    Here is a possible explanation (similar to Trollbait):

    The AHS adjusts the brightness and illuminated area of the high beams according to the vehicle speed as follows:


    In French video is mentioned: ... "we have the maximum beam width for speed 15-40 km/h" ... "and the minimum width for 80 km/h and more" ...
    So, probably it works, just the illumination range is changing from the maximum width to the minimum one.
     
    #14 unicorn, Apr 19, 2017
    Last edited: Apr 19, 2017
  15. civicdriver06

    civicdriver06 Active Member

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    A bit strange the max. width beam is cut off at 40 kmph while the max. allowed speed in most European urban areas is actually 50 kmph.
     
  16. unicorn

    unicorn Member

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    ... to be correct ... 'cca' 40 km/h (written in video)
     
  17. GT4Prius

    GT4Prius Active Member

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    Thanks.

    In fact, the car shows whether high beam is active by turning on the blue high beam indicator, and this stays off until I reach 40 mph.

    Once I have reached 40 mph adaptive high beam then comes on and it also stays on when I go below 40 but at a certain lower speed that I am not yet sure of it then turns off and won't come on again until I hit 40.

    Not sure whether this is one of the configurable thresholds that has been set wrong for my car, or just an odd design decision that the manual fails to explain or describe.

    (EDIT Ref others' reference to 40kph, I do mean 40 mph not 40 kph).

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    #17 GT4Prius, Apr 19, 2017
    Last edited: Apr 19, 2017
  18. civicdriver06

    civicdriver06 Active Member

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    Yes but that should only concern high beam,the other functions,like the width of the low beam at urban speeds should still be active .
     
  19. CharlesH

    CharlesH CA HOV Decal #5 on former PiP

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    And the reason we don't have adaptive high beam in the US is due to 20th century vehicle codes that prohibit any sort of "high beam" from being on in the presence of traffic? Kind of like all cars with an "automatic" transmission must provide a "B" mode to utilize engine braking to prevent brakes from overheating on long downhills?
     
  20. GT4Prius

    GT4Prius Active Member

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    I will make further observations next time I drive in relevant conditions. It is the high beam patterns that concern me (or the lack of them in certain circumstances).

    I did also notice that switching from the low beam to AHS and vice versa by pushing forward or pulling back the headlight stalk made no difference to what the car did in the conditions I have described, when I wanted high beams and didn't get them below 40mph.

    @RCO What is your experience of this?

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