1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Problems with Rain Sensor Wipers

Discussion in 'Gen 4 Prius Main Forum' started by LovePrius16, Jul 12, 2017.

  1. Since2002

    Since2002 Senior Lurker

    Joined:
    Nov 12, 2011
    936
    1,097
    0
    Location:
    Duluth, GA
    Vehicle:
    2006 Prius
    Model:
    N/A
    That was the danger of that design, because without the lap belt in a collision you could slide underneath the shoulder belt and slam into the dash. Or be ejected from the car. Ironically one of the reasons that many people didn't used to wear seatbelts (when it wasn't required) was they wanted to be thrown out of the vehicle. It was a common misconception that you were less likely to be injured if you were thrown out of the vehicle, although statistics have clearly proved otherwise.
     
    #41 Since2002, Mar 22, 2018
    Last edited: Mar 22, 2018
    RCO and krmcg like this.
  2. jsrprius

    jsrprius Junior Member

    Joined:
    Jul 19, 2019
    7
    0
    0
    Location:
    Texas
    Vehicle:
    2016 Prius
    Model:
    Four
    I also have observed a problem mentioned in this thread:
    I use the "auto" setting as intermittent (since it's the only way to get intermittent wiping on a car with auto?). In my case, during rain, after a while of wiping at the appropriate intermittent speed, the wipers will start going fast. Turning wipers on and off will reset them to correct speed. After a time they start going fast again.

    Question:
    1) Is "auto" supposed to include going faster when there is more rain on the windshield, even if the setting for the auto-speed is low? (I.e., does auto detect both when to start and how fast to go? Or just when to start)

    2) Is this likely a problem with the windshield wiper relay board?
     
  3. Tideland Prius

    Tideland Prius Moderator of the North
    Staff Member

    Joined:
    Oct 2, 2004
    44,904
    16,128
    41
    Location:
    Canada
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    The setting for the rain-sensing wipers isn’t speed, it’s interval (Or more correctly, sensitivity). The speed of the wipe is out of our control.

    I have noticed it go from intermittent to HI but then it settles down after a few secs.
     
    kithmo and alanclarkeau like this.
  4. jsrprius

    jsrprius Junior Member

    Joined:
    Jul 19, 2019
    7
    0
    0
    Location:
    Texas
    Vehicle:
    2016 Prius
    Model:
    Four
    Thanks. Agreed that I didn't write correctly about speed. I meant that on a low interval setting it will sometimes jump to a high interval (appearing to go "faster" with less time between wipes).


    The mechanic said "for a prius with rain-sensing wipers, the setting for low or high on auto is not the interval but rather the sensitivity. You cannot control the interval between wipes." This seems wrong (and is definitely wrong in my own experience). Is he wrong?

    But maybe he is right in some other sense, in that the rain sensing *can* cause the wiper to jump into a higher setting (less delay between wipes) even when the setting is lower? Right or wrong? Or does my prius have a problem that they're failing to diagnose?
     
  5. kithmo

    kithmo Couch Potato

    Joined:
    Apr 25, 2010
    2,404
    2,773
    47
    Location:
    South Yorkshire, UK
    Vehicle:
    2016 Prius
    I found the sensitivity setting one below the highest works best for me. Keeping the screen squeaky clean makes a big difference, I usually give it a quick squirt of the washers when it looks like rain.
     
    alanclarkeau likes this.
  6. Pulse07

    Pulse07 Active Member

    Joined:
    Feb 24, 2020
    273
    139
    0
    Location:
    East Bay, California
    Vehicle:
    2020 Prius
    Model:
    XLE AWD-e
    While I was reading the thread, I thought I was the only one that leaves it "off" when its not raining. I only turn it on to auto mode when it is raining. Glad Im not the only one.
     
  7. pianewman

    pianewman Active Member

    Joined:
    Dec 17, 2019
    264
    183
    0
    Location:
    DallasFortWorthTEXASregion
    Vehicle:
    2018 Prius
    Model:
    Two
    I do the same. In my experience, with VW and now with Toyota "rain sensing" wipers, my conclusion is they're quirky. VW had issues a few years ago, dropped them completely from their Passat line, then they came back. Initially, too many complaints.
     
    kithmo likes this.
  8. alanclarkeau

    alanclarkeau Senior Member

    Joined:
    Feb 24, 2016
    7,044
    7,584
    0
    Location:
    near Brisbane, Australia
    Vehicle:
    2016 Prius
    Model:
    N/A
    Mine went onto AUTO when I bought the car - the salesman showed me a few setups like HUD, mirrors, AUTO lights etc. The only time I touch it is if I want to wash front or back windscreens. It's worked fine for 4 years like that.
     
    krmcg likes this.
  9. kithmo

    kithmo Couch Potato

    Joined:
    Apr 25, 2010
    2,404
    2,773
    47
    Location:
    South Yorkshire, UK
    Vehicle:
    2016 Prius
    I used to call them "random wipers". I've had then on the last 4 cars I've owned and the Gen 4, although not perfect, is probably the least random of them all.
     
    krmcg and alanclarkeau like this.