Safety Sense has Trouble in Snow

Discussion in 'Prime Main Forum (2017-Current)' started by trescenzi, Dec 11, 2016.

  1. trescenzi

    trescenzi Junior Member

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    This might be something that's already known but the safety sense features lose their efficacy in snow. This evening I lost radar cruise control first, then all of the other sensors slowly got gunked up. So PSA be careful relying on these sensors in a snow storm. Long before the car realized the radar wasn't working I noticed it was waiting way too long to break. Pretty dangerous thing to happen while cruising on a highway during a snowstorm. Be careful out there and no crashing your primes!


    EDIT as a reminder to those that just look at this first post two situations, amongst the others quoted below, in which you shouldn't use CC are:

     
    #1 trescenzi, Dec 11, 2016
    Last edited: Dec 11, 2016
  2. priuscatprimeguy

    priuscatprimeguy Senior Member

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    Park assist was the first to go for me, message popped up on the dashboard.:cry:
     
  3. ForestBeekeeper

    ForestBeekeeper Active Member

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    I was wondering about that.

    We also get a lot of fog and wild animals wandering in the road [moose, deer, bear, turkey] Just this past week I have had to stop 3 times for critters as they cross the road. I hope that Safety Sense will be able to sense critters in the fog.

    We got our Prime a week and a half ago, and only yesterday were we able to get the winter studded tires installed. We are excited to be able to start driving it now. :)
     
  4. Lee Jay

    Lee Jay Senior Member

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    OM, Page 394

    Situations unsuitable for dynamic radar cruise control with full-speed range

    Do not use dynamic radar cruise control with full-speed range in any of the following situations.

    Doing so may result in inappropriate speed control and could cause an accident resulting in death or serious injury.

    ●Roads where there are pedestrians, cyclers, etc.
    ●In heavy traffic
    ●On roads with sharp bends
    ●On winding roads
    ●On slippery roads, such as those covered with rain, ice or snow
    ●On steep downhills, or where there are sudden changes between sharp up
    and down gradients
    Vehicle speed may exceed the set speed when driving down a steep hill.
    ●At entrances to freeways and highways
    When weather conditions are bad enough that they may prevent the sensors
    from detecting correctly (fog, snow, sandstorm, heavy rain, etc.)

    ●When there is rain, snow, etc. on the front surface of the radar sensor or
    camera sensor
    ●In traffic conditions that require frequent repeated acceleration and deceleration
    ●When your vehicle is during emergency towing
    ●When an approach warning buzzer is heard often
     
  5. fuzzy1

    fuzzy1 Senior Member

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    Why, oh why, were you using any form of cruise control in the snow in the first place?

    This sounds like another case of driver expectations getting ahead of the consumer market technology, just like the Tesla 'autopilot' crash.
    The following item also demands highlighting or boldface for this thread:
     
    #5 fuzzy1, Dec 11, 2016
    Last edited: Dec 11, 2016
  6. huskers

    huskers Senior Member

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    When it snows now I just stay home.
     
  7. Lee Jay

    Lee Jay Senior Member

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    Correct - never use cruise control in any sort of slippery or potentially slippery conditions. Such conditions require the steadiest possible throttle control and cruise control won't do that, it'll just maintain speed. Adaptive cruise is even worse because it will alter speed as well.
     
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  8. trescenzi

    trescenzi Junior Member

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    Nah it was just something I noticed while driving on the highway. As it started to snow the sensors started to get a bit less precise as it makes sense they would. Figured I'd share the observation with others who might be in similar driving situations.

    I think the key is to not rely on safety sense for anything. It's mostly intended as a backup measure or a minor convenience feature. Given that Toyota says a lot of the anti-collision features rely on lasers and cameras I'd imagine that fog could be an issue. I'd defer to what Lee Jay quoted about fog being something that can mess it up.
     
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  9. fuzzy1

    fuzzy1 Senior Member

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    I'm suspecting that TC and VSC will compensate or cover some of the foul weather hazards of old style CC. But not well enough to make use of even current CCs an acceptable driving practice in such conditions.

    ---------------------

    We can't 'rely' on these features until we have true self-driving cars. They won't be available until at least 2020.
     
    #9 fuzzy1, Dec 11, 2016
    Last edited: Dec 11, 2016
  10. Lee Jay

    Lee Jay Senior Member

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    My 2004 has both of those. Actually, TC is annoying and of negative value in many situations.

    Right.
     
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  11. trescenzi

    trescenzi Junior Member

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    I've edited the first post to call that and the other bolder point out. Good points all around on the fact that CC shouldn't be being used in the situations I described anyways.


    iPhone ?
     
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  12. Prius Maximus

    Prius Maximus Senior Member

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    Absolutely. CC of any kind should not be used in snow or icy or even rainy conditions. What's CC going to do when you start hydroplaning? By the time you cancel it and try to take control, it may be too late.

    Here's another PSA - for those with 4WD... never use it above 45 MPH - 1st the drive train isn't designed for it, 2nd, it's not safe. If you need 4WD you shouldn't be going over 45 MPH.

    AWD is a different story for the design aspect, but again, with AWD think about it like you had 2WD - if you thought you would need 4WD in bad conditions, SLOW DOWN!!!!
     
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  13. Lee Jay

    Lee Jay Senior Member

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    I use AWD generally below 15mph. Doesn't help you stop. That's why I like the E-Four option for the G4 Prius. It's just for lower speeds and should have plenty of power for that purpose because of its very low gearing and despite its very low power rating.
     
  14. trescenzi

    trescenzi Junior Member

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    While we're on the topic of safely driving in slippery conditions what's the opinion/guidance on using B mode to slow yourself at lower speeds in such conditions? I'm coming from a 5 speed manual so I'm used to relying largely on being in a lower gear when going at lower speeds in the snow and brakes only for the last bit of slowing down. Can/should B mode be used in a similar manner?
     
  15. Lee Jay

    Lee Jay Senior Member

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    Using B mode is okay, but be aware it only engages the front wheels, same as lightly using the brake pedal.
     
  16. Coast Cruiser

    Coast Cruiser Senior Member

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    There are several long threads about the B mode. Not recommended for use on flat ground.
    I have not had any luck with mine. When going down a hill it does not slow the car down, and I am back on the brakes.
     
  17. Lee Jay

    Lee Jay Senior Member

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    What does this mean? It certainly works as advertised on my 2004. I didn't try it on a Prime and haven't seen any threads on it.
     
  18. Coast Cruiser

    Coast Cruiser Senior Member

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    I saw the B mode threads in the Gen3 & Gen4 forums. (The B mode is the same on the Prime?)
    On my 2016, I have never felt the B mode slow the car when going down a fairly steep hill of 1/2 to 1 mile long. That's just my personal experience. I have to ride the brakes most of the way down the hill, otherwise my car will keep accelerating. I would sure hate to be going down a snowy or icy hill in my car. That's just my personal opinion. I don't trust the B mode.
     
  19. Lee Jay

    Lee Jay Senior Member

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    In Ev mode, B should increase regeneration. On a 2016 liftback, B should increase engine RPM to increase engine braking. It works just fine on my 2004 and I've used it on hills longer than 7 miles.
     
  20. ttait

    ttait Active Member

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    What is this 'snow' that so many of you are going on about? :sneaky:
     
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