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Horn Only Works With Steering Wheel Turned

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Kevin_Denver, Aug 20, 2016.

  1. Kevin_Denver

    Kevin_Denver Active Member

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    My horn on my 2009 (80k miles) has been working intermittently, but has recently gotten worse. I figured out that it only works when the steering wheel is in certain positions. If the top of the wheel is pointed between 6 and 9 o'clock it beeps, but doesn't in other positions. Also I looked at lots of other things before figuring this out - fuse is okay, wiring to horn is good, relay in Unit C is working well.

    Looking at other forums for people with the same problem in other cars, this looks like it's related to a ring on the turn signal switch assembly that is part of the horn circuit in the steering wheel. I've understood that in most cars and presumably the Prius there's a spring loaded contact in touch with this ring, and it may need to be cleaned up or replaced.

    I've experienced with other electronics that sometimes turning a knob back and forth wipes/scratches corrosion off enough to restore a part, so I tried turning the steering wheel back and forth several times, but it didn't make a difference (and I didn't really expect it to - the steering wheel gets turned every day well in both directions from daily driving).

    I also checked and all of the other buttons on the steering wheel are working as expected - ventilation controls, audio controls, cruise control.

    Edit: I found a video of someone replacing the part on another Toyota, and it looks like Toyota uses the same part for virtually Toyota models. The part is called a clock spring, and it can be found on ebay for $12-15. I believe replacing this will fix my problem.



    I've ordered the part and will let you know how it goes.

    Has anyone had a similar problem and was able to fix it?
     
    #1 Kevin_Denver, Aug 20, 2016
    Last edited: Aug 20, 2016
  2. ChapmanF

    ChapmanF Senior Member

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    What you've described is a classic problem with the spiral cable a/k/a clock spring, so as long as you've bought the right one (there are differences even between different Prius generations) it should definitely solve your problem.

    The price you've reported for the eBay part is a lot less than the Toyota OE part, so here's hoping the quality is at least good enough to keep your problem solved for a useful amount of time.

    Double check the airbag safety procedures before diving in.

    -Chap
     
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  3. dolj

    dolj Senior Member

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    Several people have had this problem and many have fixed it themselves. I'm surprised you have not turned up any threads by searching the "Gen 2 Prius Care, Maintenance and Troubleshooting" forum with the search string "clock spring".

    Anyway, many have used a cheap knock-off part off eBay/Amazon and regretted it because the part proves to be inferior and fails quickly. The consensus, using hind-sight, is that if they had to do it again they would spring (see what did there?–lol) for the genuine Toyota clock spring. It is around the fact that the repair involves taking off the steering wheel and therefore messing with the air-bag.

    Just bought I'd pass along the info.
     
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  4. andrewclaus

    andrewclaus Active Member

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    Yep, it's the clockspring, formally called the spiral cable. There is a good write-up here on replacing it. Definitely use your VIN to buy a replacement, as they do vary among model year. If you have VSC, there's another step involved in getting the steering sensor moved. Usually the first symptom is the A/C functions stop working, then the cruise control.

    I used the cheap ($25) eBay part and did okay with it, as far as I know. The housing is identical, but the pins were inferior. The worry for many is that the SRS conductors and contacts are just good enough for supervisory function, but not good enough to fire the airbag.

    It's not a tough project if you know the basics of working with the airbag and have the right Torx driver.
     
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  5. Kevin_Denver

    Kevin_Denver Active Member

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    Thanks all.

    The $12 spiral cable/clock spring I ordered off Ebay arrived and I installed it last night, which was easy to do as the process is identical to other Toyotas (other than the fact that the Prius steering wheel never locks; you have to turn it all of the way to screw and unscrew). It solved the problem - horn now works great in all positions! All other controls work fine too.

    The Toyota genuine part is $200+ new, so considering that I would have to replace it 16 times for costs to be equal, I went with the cheaper replacement. If it fails again, I can now replace the whole thing in 15 minutes; it's really not too difficult. I'm not worried about it not being able to fire the airbag. If there's a connection, there's a connection, and it only needs to turn hot for a few ms to initiate firing of the airbag.

    For anyone else who runs into the same problem, the main safety thing to do is to disconnect the battery and then wait two minutes before starting any work, as the modules store charge for up to 90 seconds and can fire the airbag during that time even if they don't have power.
     
  6. JC91006

    JC91006 Senior Member

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    Those Chinese clock springs are known to be problematic.
     
  7. xliderider

    xliderider Senior Member

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    And in the news now... the Chinese will start manufacturing jet aircraft engines...

    I wonder how reliable they'll be? :whistle:
     
  8. analoggirl

    analoggirl Junior Member

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    Hi Chap,
    I've been trolling this issue for a few days. Your responses have been a wealth of information. The dealership is telling me the assembly needed to replace my spiral cable is part and parcel with the airbag is is $800+ for part alone. Do you know if this is true for 2011? I do NOT trust the new ownership of our dealership in town, and unfortunately it's my only "genuine" option. I've watched enough videos to be ok with attempting this myself, but I need to know I have the correct part, and if I need a steering wheel pull. Most all the youtube videos I've watched the steering wheel seems to come off easily. I appreciate your knowledge. And assume (correctly) that I haven't done this before.
    Thanks!!
     
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  9. bisco

    bisco cookie crumbler

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    the airbag is the biggest issue, be careful!:eek:
     
  10. ChapmanF

    ChapmanF Senior Member

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    It is not part and parcel with the airbag; the airbag is item 45130 while the spiral cable is 84307 below.

    [​IMG]

    [​IMG]

    The spiral cable does have a suggested list of $780.37 though. (I believe there's an angle sensor integrated with it.)

    Most Toyota dealers selling online seem to be discounting somewhere in the 24 to 30 percent range. Sometimes you can get a decent discount at the parts counter too if you ask, maybe not quite as good as the online offers, but you won't pay shipping, so there's that.

    I, myself, would never try to bang or yank the steering wheel off the shaft without a puller. The splines in the shaft and wheel are shallow and fine and nobody wants them to get a bit rounded. The puller will pull the wheel off in one straight shot, and will easily recoup the zero dollars you'll probably pay to borrow one.

    Putting the wheel back on also demands a delicate touch because of those splines ... sort of gently float the wheel back down onto the shaft and make sure you feel for when the splines have aligned before tightening anything down (but don't try to feel for spline alignment by exuberantly twisting it, or you'll grind 'em right down!).

    -Chap
     
  11. Elektroingenieur

    Elektroingenieur Senior Member

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    The same part (84307-47020) is also used on Prius cars built for sale in Japan, and it’s available from the parts sales network there at a list price of ¥25,300, or about $225 at today’s JPY/USD exchange rate. If you can wait a few days, you could take advantage of this by ordering from one of the exporting companies that sells new Toyota parts from Japan to the United States, about which I’ve written previously.
     
  12. Petrodollar

    Petrodollar Member

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    For those who want the Toyota OEM part rather than replacing a cheap knock-off part multiple times:
    For 2nd Gen 2004 - 2009:
    Cable Sub-Assembly, Spiral With Sensor
    P/N 84306-0E010, $317.84 list price, $209.23 (+ $9.96 Shipping) at McGeorge Toyota OnlineParts (Richmond, Virginia)

    (
    2009 Toyota Prius Hatchback Touring HYBRID Cable sub-assembly. Spiral; spiral with sensor. Audio, steering, leather - 843060E010 | Toyota
    ) (nice photo on this page, click to zoom)
    (
    SWITCH & RELAY & COMPUTER. For 2009 Toyota Prius Hatchback Touring HYBRID | Toyota
    )

    (Clock Spring - Toyota (84306-0E010) | Toyota Parts)
     
    #12 Petrodollar, Jul 14, 2018
    Last edited: Jul 14, 2018
  13. ChapmanF

    ChapmanF Senior Member

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    That's a stunning price difference compared to $780 for the same part from a US dealer. What accounts for it? Is it that Toyota USA has to pay the duties/tariffs to bring them in, which you can get away with not paying as long as your purchase is less than the "de minimis" ($800 as of 2016) threshold?

    How steep are the duties/tariffs on those sorts of parts?

    That looks like the part number and price for a Gen 2, which is fair, as this started as a Gen 2 thread in the Gen 2 forum, but when analoggirl tagged onto it, it sprouted some Gen 3 info also, a much pricier part, because of the integrated angle sensor, I guess.

    -Chap
     
  14. Elektroingenieur

    Elektroingenieur Senior Member

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    I don’t know, but I doubt it’s the customs duty, which I imagine would be only 2.5% ad valorem, for subheading 8708.94.75, Harmonized Tariff Schedule of the United States, which provides for Parts and accessories of the motor vehicles of headings 8701 to 8705: Other parts and accessories: Steering wheels, steering colums and steering boxes; parts thereof: Parts: For other vehicles: Other.

    The U.S. price may also reflect transportation costs, including ocean freight from Japan and domestic shipping to the dealer; the cost of holding parts in inventory at a U.S. distribution center; higher product liability expense; and market conditions—a polite way of saying that prices are higher here because they can be.