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2022 adaptive cruise control not reliable?

Discussion in 'Gen 4 Prius Main Forum' started by SteveK2024, May 7, 2024.

  1. SteveK2024

    SteveK2024 New Member

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    I noticed that adaptive cruise control does not slow down sometimes when the car in front slows down.
    Is this a known problem with cruise control or is it defective in my car? It works fine most of the time. I see this problem only sometimes. Could the sensor in front Toyota logo be bad?
     
  2. sylvaing

    sylvaing Active Member

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    How's the weather like when it doesn't slow down?
     
  3. FuelMiser

    FuelMiser Senior Member

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    Have never seen this in our 2016. Dynamic CC has always worked safely.
     
  4. sclevine

    sclevine Active Member

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    Have not seen this either in my 2017 or my 2024. If anything, it errs on the side of slowing down when it doesn't need to.
     
  5. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Are you sure it is in adaptive mode, and not simple cruise mode where it would normally not react to a slowing leader?
     
  6. Doug McC

    Doug McC Active Member

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    Haven’t had any issues with our 2022 Nightshade Edition XLE. What are the ambient light conditions when it happens or possibly the shape of the vehicle in front of you?

    EDIT: pages 335 and 336 in your Owners Manual list quite a few conditions that will cause the system to not respond “correctly”. Several of them could easily be a fairly common occurrence IMHO.


    ■ When the sensor may not be correctly detecting the vehicle ahead
    In the case of the following and depending on the conditions, operate the brake pedal when deceleration of the system is insufficient or operate the accelerator pedal when acceleration is required.
    As the sensor may not be able to correctly detect these types of vehicles, the approach warning (P. 331) may not be activated.
    ●Vehicles that cut in suddenly
    ●Vehicles traveling at low speeds
    ●Vehicles that are not moving in the same lane
    ●Vehicles with small rear ends (trailers with no load on board, etc.)
    ●Motorcycles traveling in the same lane
    ●When water or snow thrown up by the surrounding vehicles hinders the
    detecting of the sensor
    ●When your vehicle is pointing upwards (caused by a heavy load in the luggage compartment, etc.)
    ●Preceding vehicle has an extremely high ground clearance


    ■Conditions under which the vehicle-to-vehicle distance control mode may not function correctly
    In the case of the following conditions, operate the brake pedal (or accelera- tor pedal, depending on the situation) as necessary.
    As the sensor may not be able to correctly detect vehicles ahead, the system may not operate properly.
    ●When the road curves or when the lanes are narrow
    ●When steering wheel operation or your position in the lane is unstable
    ●When the vehicle ahead of you decelerates suddenly
    ●When driving on a road surrounded by a structure, such as in a tunnel or on
    a bridge
    ●While the vehicle speed is decreasing to the set speed after the vehicle accelerates by depressing the accelerator pedal
     
    #6 Doug McC, May 8, 2024
    Last edited: May 8, 2024
  7. SteveK2024

    SteveK2024 New Member

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    Yes, because it works most of the time and accelerates/decelerates correctly.
     
  8. SteveK2024

    SteveK2024 New Member

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    Thanks for sharing this list. I'll check next time if any of these situations cause it to not work.
     
    Doug McC likes this.
  9. BiomedO1

    BiomedO1 Senior Member

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    Never had an issue with mine; but don't try using it while raining. I believe that's in the manual. It seems to do fine in foggy conditions - but I'm too much of a control freak to enable it for any length of time.
     
    sylvaing likes this.
  10. sylvaing

    sylvaing Active Member

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    That's why I asked what was the weather like. Never got an answer.