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Cruise control behavior

Discussion in 'Prime Main Forum (2017-2022)' started by Billy sharpstick, Jul 26, 2019.

  1. Billy sharpstick

    Billy sharpstick Junior Member

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    Location:
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    Vehicle:
    2019 Prius Prime
    Model:
    Prime Premium
    New car, and I'm just exploring the features.
    My CC is not working consistently.
    I was using it recently and it followed the car ahead all the way down to a complete stop, as described in the manual. It worked this way several times. I was pleased because my Ford beeps and disconnects at 12mph.
    Then last night, it beeped and disconnected at a low speed(not sure exactly what). This was a normal stop at a light, no extreme speed changes or sudden stopping.
    I'm probably not understanding what it is doing.
     
  2. schja01

    schja01 One of very few in Chicagoland

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    Every one of the few times CC disengaged for me there was a message on the MID indicating why it disengaged. eg. "No Longer Following a Vehicle" (or similar) is the one I've gotten the most when the car in front turns off the roadway.
    I think the manual warns you are really not suppose to use CC in stop and go traffic except on Expressways.
    I use it mostly to keep from exceeding the speed limits as my Car Insurance App dings my score for speeding.
     
  3. Blauer Glimmer

    Blauer Glimmer Active Member

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    Location:
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    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    From the manual:
    Approach warning (vehicle-to-vehicle distance control mode)
    When your vehicle is too close to a vehicle ahead, and sufficient automatic deceleration via the cruise control is not possible, the display will flash and the buzzer will sound to alert the driver. An example of this would be if another driver cuts in front of you while you are following a vehicle. Depress the brake pedal to ensure an appropriate vehicle-to vehicle distance.
    Warnings may not occur when
    In the following instances, warnings may not occur even when the vehicle-to vehicle distance is small.
    ● When the speed of the preceding vehicle matches or exceeds your vehicle speed
    ● When the preceding vehicle is traveling at an extremely slow speed
    ● Immediately after the cruise control speed was set
    ● When depressing the accelerator pedal​
     
    #3 Blauer Glimmer, Jul 26, 2019
    Last edited: Jul 26, 2019
  4. Billy sharpstick

    Billy sharpstick Junior Member

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    Location:
    Micanopy FL USA
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Premium
    Seems like it should resume the set speed once the preceding car is gone. I'll test it more today and try to figure it out.
     
  5. Blauer Glimmer

    Blauer Glimmer Active Member

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    Prime Advanced
    Sorry, I meant to post this about cancellation of DRCC from the manual :oops:

    Automatic cancelation of vehicle-to-vehicle distance control mode
    Vehicle-to-vehicle distance control mode is automatically canceled in the following situations.
    • Actual vehicle speed falls below approximately 25 mph (40 km/h) when there are no vehicles ahead.
    • The preceding vehicle leaves the lane when your vehicle is following at a vehicle speed below approximately 25 mph (40 km/h). Otherwise, the sensor can not properly detect the vehicle.
    • VSC is activated.
    • TRAC is activated for a period of time.
    • When the VSC or TRAC system is turned off by pressing the VSC OFF switch.
    • The sensor cannot detect correctly because it is covered in some way.
    • Pre-collision braking is activated.
    • Intelligent Clearance Sonar is operated. (if equipped)
    • The parking brake is operated.
    • The vehicle is stopped by system control on a steep incline.
    • The following are detected when the vehicle has been stopped by system control:
      • The driver is not wearing a seat belt.
      • The driver’s door is opened.
      • The vehicle has been stopped for about 3 minutes.
        In this situation, the shift position may automatically switch to P. (→P. 333)
    If vehicle-to-vehicle distance control mode is automatically canceled for any other reason, there may be a malfunction in the system. Contact your Toyota dealer.

    Could your issue fall under the first bullet?
     
  6. schja01

    schja01 One of very few in Chicagoland

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    I "Believe" that "Engaging B Mode" should be added to the list.
    It appears to me that Radar Cruise Control (maybe Cruise Control too) is/are mutually
    exclusive of "B Mode".
    I had DRCC disengage a few times (I don't believe there was any warning/message) when I
    engaged "B Mode" and when I was already in "B Mode" I could not engage DRCC.
     
  7. Blauer Glimmer

    Blauer Glimmer Active Member

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    Yes, that is true. Neither cruise control option works in B Mode.
     
    Prius from Dad likes this.