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

Radar cruise control

Discussion in 'Gen 4 Prius Audio and Electronics' started by Pauls Lugar, Mar 12, 2021.

  1. Pauls Lugar

    Pauls Lugar New Member

    Joined:
    Mar 17, 2020
    1
    0
    0
    Location:
    Spring Valley, WI
    Vehicle:
    2018 Prius
    Model:
    Two
    Can a radar sensor be tested before replacing it? My 2018 Prius hit the car in front of it in a car wash. The emblem is broken. The radar cruise control mostly works, but intermittently gives a warning that says “Clean radar sensor.” It has happened 3 times. Today I noticed that it happened when I went around a curve. I am not sure the sensor needs to be replaced, but that is what the body shop will do. Is there any way to test the sensor to be sure it is defective? Can I just replace the emblem without replacing the sensor? Will druise work with a defective sensor if I just use it in conventional cruise control mode?
     
  2. Elektroingenieur

    Elektroingenieur Senior Member

    Joined:
    Jan 8, 2017
    2,515
    3,253
    9
    Location:
    California
    Vehicle:
    2016 Prius
    Model:
    Three Touring
    If it’s broken, the emblem assembly (discussed in my October 2017 posting) should be replaced.
    The only other parts that would have to be replaced at the same time as the emblem assembly are the two spring nuts, part number 90183-06031.

    If a new emblem assembly doesn’t fix the problem, the radar beam axis adjustment procedure, described in the Repair Manual (more info) and briefly in my February 2018 and March 2019 postings, should be done. A new millimeter wave radar sensor assembly (part number 88210-07010) would be the last resort, and probably isn’t needed, if there are no messages or warning lights other than “Clean Radar Sensor.”
    The sensor assembly has a built-in self-test feature, and the adjustment procedure is effectively a further test.

    Parts catalog references:
     
    alanclarkeau likes this.
  3. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,491
    14,100
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    If that's all that's broken, that's probably all you need to replace. The sensor is well behind it.

    Edit to add. Just to be sure, I went out and removed the plastic trim covering that area and it looks like the sensor is about an inch behind the emblem, held on by brackets.
     
    #3 jerrymildred, Mar 14, 2021
    Last edited: Mar 14, 2021
    alanclarkeau likes this.
  4. varmonter

    varmonter Junior Member

    Joined:
    Mar 21, 2021
    10
    6
    0
    Location:
    vt
    Vehicle:
    2020 Prius Prime
    Model:
    LE
    perhaps the sensor is detecting the cracked emblem and thinks its dirty.
     
    jerrymildred likes this.
  5. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,491
    14,100
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    That would be my first guess, too.