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Foreign Object on Wheel Speed Sensor Questions

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by rjparker, Apr 18, 2014.

  1. rjparker

    rjparker Tu Humilde Sirviente

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    This morning my 2012 Prius v's ABS, Skid Control and Tire Pressure indicators all came on at once and would not reset with a restart. I took the car to a dealer who diagnosed "C1235 Foreign Object on RF Wheel Sensor". They removed the right front Hub Bearing and found a thin piece of metal attached to the speed sensor rotor. Unfortunately they claimed this is not covered by the factory warranty, so 3.5 hours and $200 lighter it was fixed. I asked the service advisor if this is a normal occurrence and if I could have cleaned it somehow to resolve. He said, no not normal and no I could not have cleaned it as the speed sensor with the piece of metal attached is in a sealed hub. The hub was removed to access the speed sensor, which was then cleaned of the foreign material, and then reassembled.

    Questions:
    1. Has this happened to anyone?
    2. Any speculation on how the "thin piece of metal" got there?
    3. Should this repair, in a "sealed" unit, have been handled as warranty work?
     
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  2. rdgrimes

    rdgrimes Senior Member

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    I vote for it being a defect in materials or workmanship, ie warranty work. Unless they have a plausible explanation on how that debris got there, the factory put it there. If the dealer is no help, escalate this to the Toyota district rep.
     
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  3. WilDavis

    WilDavis Senior Member

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    …do you have a pic of the "thin piece of metal"? …and is it magnetic? The reason I ask is whilst clearing snow 3 snow-storms ago, I found a piece of metal about ¾" x ½" and about the thickness of a nickel near one of ChuggyPig's wheels (I thought it might have been a balance weight, but they're usually made of lead, and are not magnetic (this piece is - it stuck to my snow-shovel!)
     
  4. rjparker

    rjparker Tu Humilde Sirviente

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    No pic of the offending "foreign object" but I do question how a piece of metal gets inside a sealed hub to cause trouble with the speed sensor. Especially when the hub and bearing are sealed well enough to keep out water and normal dirt while keeping it's grease in. The Service Manager says any code that includes "Foreign Object" will be denied for warranty by Toyota. At the same time, the Manager and Advisor maintain the Hub seal remains intact and did not need replacement.
     
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  5. bisco

    bisco cookie crumbler

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    how do these guys keep a straight face while talking to customers? it must be quite a talent.:rolleyes:
     
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  6. rdgrimes

    rdgrimes Senior Member

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    I call BS and strongly suggest an escalation to Toyota.
     
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  7. EZW1

    EZW1 Active Member

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    Before you escalate it, make sure you get the problem they discovered from them in writing, if they haven't already done that. Just coding 'foreign object' on your work ticket is cheap way out. If they don't give you anything in writing, then ask for your money back on grounds they bilked you on your repair and will not back it up. They likely will write it out for you.

    Don
     
  8. rjparker

    rjparker Tu Humilde Sirviente

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    The work order basically says "...removed the right front Hub Bearing and found a thin piece of metal attached to the speed sensor rotor". I am going in this week and have the service manager show how it might get in there.
     
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  9. kithmo

    kithmo Couch Potato

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    Alien Abduction :cautious:

    C1235 is RR Wheel Speed input signal missing.
     
  10. rjparker

    rjparker Tu Humilde Sirviente

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    I am going in to the dealer for a show and tell. Here's a pdf with details on code 1235 (right front). It's from a 2004 Prius but it appears to be the same. See troubleshooting step 4.

    link to c1235.pdf
     
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  11. Azra

    Azra New Member

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    Is the speed sensor inside the wheel barring of the rear passenger hub?

    My ABS light and Traction control light are illuminated. I had Toyota diagnose it, they told me I would need a wheel barring, I think maybe they said an ABS sensor harness...not entirely sure.

    Do I need to buy the ABS sensor on rear passenger wheel? If so, where do I find this item to buy? I have a rear passenger wheel barring and speed sensor wire harness.

    Thanks for any help!
    I've only had this car for a year!
     
  12. rjparker

    rjparker Tu Humilde Sirviente

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    I believe each wheel has a sensor next to each wheel hub, which is a sealed assembly that acts like a bearing. It took Toyota 3.5 hrs to do mine, but they charged probably 2 hours. No new parts. I think there are some suspension parts and brakes that have to come off but don't quote me on that. A $15 visit to Toyota's TIS system would give you the procedures. The work order basically said "...removed the right front Hub Bearing and found a thin piece of metal attached to the speed sensor rotor". They did not change the hub.
     
  13. Air_Boss

    Air_Boss Senior Member

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    A similar occurrence was previously reported on PC. Foreign Object attack on sealed hub... Uh huh.
     
  14. Melthias

    Melthias Junior Member

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    My prius will pretty reliably light up with all the same lights whenever I go above 78mph. I replaced the sensor and this still happens. I generally keep 65-70 as my top speed, but sometimes my wife goes a little faster and the dash will light up. Usually the lights go away after driving at low speeds or a restart of the car. It sounds like maybe I should take a look inside, but would need to see what is involved to take the hub bearing off.
     
  15. Melthias

    Melthias Junior Member

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    I have looked at the code with Techstream and it says there is an object stuck inside front left hub.
     
  16. Melthias

    Melthias Junior Member

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    I took it apart and cleaned around a bit. A lot of dust and built up grim but no metal pieces. I then took it up to 82mph and no lights, so we will see if it stays fixed!
     
  17. Melthias

    Melthias Junior Member

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    Well, so far so good, it seems like it just needed a little cleaning.
     
  18. copa_milano

    copa_milano New Member

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    Just had the same issue several days ago, also after a snow storm. My code reading is C0210 "Rear Speed Sensor RH Circuit" and C1238 "Foreign Object is Attached on Tip of Rear Speed Sensor RH". Am on the edge of whether or not I should DIY or just find a mechanic to have it fixed. Any suggestions from the forum would be appreciated. Thank you in advance.
     
  19. Air_Boss

    Air_Boss Senior Member

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    Clean the ringer and clean its harness connector.
     
  20. Melthias

    Melthias Junior Member

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    So this problem went away for a long time but now I keep getting the issue with something attached to the left front sensor. It started happening when I went above 20mph. I opened it up again, cleaned it with a brush and compressed air and put a light coat of wd-40 on the rusting metal on the CV axle. Now it is lighting up every time I go above 70mph or so. Same fault code (foreign object). When I replaced the sensor about 6 months ago I went with a cheap one off of Ebay, which did not make my problem go away at that time. All that worked was cleaning it, but now the problem is coming up again even though I have cleaned it like 3 times, both where the axle is as well as cleaning off the tip of the sensor. At this point I am not sure what to do, I could replace the sensor though I am reading 1.7Kohms which I guess meas that it is still good. The other thing I could do is replace the ABS ECU, but that seems a bit drastic? How would I narrow that down as the problem?