DRCC (Dynamic Radar Cruise Control) Weirdness

Discussion in 'Prime Main Forum (2017-Current)' started by schja01, Apr 20, 2021.

  1. schja01

    schja01 One of very few in Chicagoland

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    Was out driving today in light snow and light rain I was on I-294 in Chicagoland with DRCC engaged at 65 mph. The car in front of me was doing 60 mph and therefore so was I. I had the distance setting at default (furthest). The car immediately in front of me left the lane so DRCC sped up to 65 mph to close the gap to the next car. Instead of eventually matching the leading vehicle my car accelerated to 65 mph and if I did not intervene would have rear ended (I felt it would at least) so I disengaged DRCC and let the vehicle gap increase. I reengaged DRCC and it tracked the leading car as expected UNTIL it too left the lane and the above scenario repeated itself. I felt the car would hit the leading car. i disengaged and reengaged DRCC and it again tracked the leading car as expected. When that car left the lane I paid attention to the DRCC graphic on the MID and noticed the graphic of the leading car was blinking rapidly on and off right up to the point I once again had to intervene to prevent a rear end accident. I'm guessing the blinking car icon/graphic is an indication it was confused (due to snow/rain?) but I think it should just have disengaged or flashed a message that it has lost or doesn't have a good lock on the vehicle it's following. Anyone else have an experience like this? J
     
  2. rdgrimes

    rdgrimes Senior Member

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    Snow/ice buildup on the radar and other sensors or cameras will effect these systems. Pretty sure its mentioned in the manual and recommended that you not use them in weather.
     
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  3. jerrymildred

    jerrymildred Senior Member

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    It sounds like it was right on the edge of seeing and not seeing the other cars due to stuff on the front of your car and stuff in the air in front of your car. It might be that in that situation, the system isn't programmed well enough to make a solid decision to disengage.
     
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  4. OldnCrusty

    OldnCrusty Junior Member

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    I've also noticed that snow/ice and heavy rain cause the DRCC to not function well. Not really a surprise for a radar based system. It happens to all of us. Think of how your visual acuity decreases in 'weather.'
     
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  5. schja01

    schja01 One of very few in Chicagoland

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    My thoughts too but definitely light precipitation.
     
  6. RovinRon

    RovinRon Junior Member

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    Any driver safety instructor and probably any cop will tell you to NOT use CC in adverse weather and or heavy traffic conditions. As stated earlier, pretty sure the manual says the same thing. Doesn't it just seem like a common sense type of thing to not use it in those weather conditions?
     
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  7. schja01

    schja01 One of very few in Chicagoland

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    Except the precipitation was very light IMO. The auto wipers barely cycled even on the highest setting. So what I think is the DRCC should not be used in ANY precipitation. I can do that.
     
  8. BiomedO1

    BiomedO1 Member

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    When I was a computer programmer; in another life, we used to say - " a computer does what you tell it to do; NOT what you want it to do".
    If that makes senses to y'all.:eek::confused::mad::sleep:
     
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  9. Froglegs

    Froglegs Junior Member

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    Mine also doesn't work great even in light rain. My Mercedes worked flawlessly, unless snow built up on the sensor. Which happened pretty much every time I drove while it was snowing.
     
  10. Trollbait

    Trollbait It's a D&D thing

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    Did the Mercedes use the same type of sensor has Toyota?
     
  11. Froglegs

    Froglegs Junior Member

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    They're both radar ... that's all I know.
     
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  12. Trollbait

    Trollbait It's a D&D thing

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    They could be different frequencies. The mm band Toyota uses does lose effectiveness with water droplets in the air. Mercedes could simply be using more than one sensor.
     
  13. Ovation

    Ovation Junior Member

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    Cruise control should never be used in any inclement weather once pavement becomes fully wet. Any dynamic system that relays on radar is likely to be even more problematic, as even before pavement gets wet, it can be confused by raindrops and/or snowflakes.
     
  14. GregersonIT

    GregersonIT Member

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    It's wierd, if there is a fair amount of mist coming off the car in front of you the sensor is pretty much blind on the Prime. My 2014 Mazda3 wasn't afflicted by this issue. But in all reality you shouldn't be using the cruise control in the rain or snow anyways.
     
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  15. Trollbait

    Trollbait It's a D&D thing

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    Different companies can be using different technology to attain the same goal. Toyota is using mm band radar and Subaru cameras for example.
     
  16. GregersonIT

    GregersonIT Member

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    Mazda is also us
    Mazda apparently uses a nearly similar tech. It could be how the visual is coming across though.
     
  17. Trollbait

    Trollbait It's a D&D thing

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    Could be a different wavelength, sensor placement, or even the use of multiple sensors over just one.
     
  18. GregersonIT

    GregersonIT Member

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    Likely. I think they use two in the front bumper behind the plastic.
     
  19. wjtracy

    wjtracy Senior Member

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    2020 RAV4 seems decent in rain and fog. I suppose I should be more careful though. Had some fog in the Appalachian mountains last week and it seemed obvious the pick-up trucks going faster than me must have had the radar on too.
     
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