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Dealer says to replace Speed Sensor and Harness, parts advice please.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by MinnesotaPriusDriver, Apr 25, 2018.

  1. MinnesotaPriusDriver

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    My traction control, abs, brake lights have been turning off and on. When they all turn on the regenerative braking goes away, but usually when restarting the car they work again, for a while. I wanted to get this checked out as soon as possible and brought my car in for an oil change at the dealer hoping they would tell me what's going on for free, no that cost $135.

    They told me the passenger rear speed sensor and harness is corroded and needs to be replaced. They quoted $769 to replace it. They wanted me to take a loaner to work while they fixed it but I said no I have to go and quickly paid and left to arrive at work on time.

    I was trying to clarify with the person giving me the bad news is this a bad wheel assembly or what exactly is a speed sensor and harness. He was young and didn't really know the answer, he just said bring it back and we'll get you all fixed up. I didn't have time to talk to someone else or I would have been late.

    I'm attaching a snippet of the paperwork showing how they describe replacing the speed sensor and harness. I've also attached photos of the parts I am seeing online to do this work myself and save some money. Can anyone provide advice, am I looking at the correct parts to replace? Thank you for your help!
     

    Attached Files:

  2. tankyuong

    tankyuong Senior Member

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    Harnesse# usually never go bad.jst replace the bearing
     
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  3. MinnesotaPriusDriver

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    Thank you for the advice! I will do this and report back.
     
  4. Elektroingenieur

    Elektroingenieur Senior Member

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    That may be true, in general, but if the dealer technician actually saw corrosion on the connector pins—as the repair estimate states—then the sealed connector at the end of the harness is probably no longer keeping moisture out. In this case, it would be prudent to replace the harness, too.

    In principle, one could instead splice on a new connector housing, terminals, and seals, using the techniques in the Wire Harness Repair Manual (PDF), but I imagine this would be less cost effective, and ultimately less reliable, than a new speed sensor wire harness (89516-47090, list price $44.79).

    Parts catalog references:
     
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  5. frodoz737

    frodoz737 Top Wrench

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    Based on what the diagnostic says and your reported symptoms, this could possibly be fixed by just doing a little connector maintenance. Assuming the connector/s are not "burned" or otherwise "broken"...get some contact cleaner spray, alcohol, "clean" lint free rags and some compressed air to clean up the male and female sides of both connectors. Where it mates to the sensor and where the "harness" mates to the vehicle harness (look at the picture of the "new" harness for reference). Plugging and un-plugging a few times each will help during this process. Do your little restart or battery disconnect and see what happens. If all is good after that...water proof those connectors and move on.

    Corroded and dirty connectors/pins can be cleaned/restored...and broken wires can be fixed.

    You just might save a butt load of money.

    Good luck.
     
  6. MinnesotaPriusDriver

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    Thanks guys! I ordered a new wiring harness too and it's on it's way. I live in an apartment so it's tough for me to work on vehicles but I know and Independent mechanic and I will be bringing it there next Friday. He will let me look at what he finds and any parts I don't need I'll return. I'll report back the results!
     
  7. Shaneg

    Shaneg New Member

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    Same exact issue. Did cleaning up the wire fix the problem? Or was harness replacement the fix? Do you recall if the mechanic that you used recommended anything different?
     
  8. Noeylicious

    Noeylicious Junior Member

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    What happened to this one? any updates?
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    One thing: the speed sensor connector is near impossible to disconnect (without breaking...), say for a look-see at the pin connections. And it's down nice and low, gets the salt and grit.
     
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  10. Noeylicious

    Noeylicious Junior Member

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    Issue fix now for me. Dealer replaced the front passenger side speed sensor. They fixed the Rear driver side Speed sensor cable.
     
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