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Power steering: is this normal?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by JayGoldstein, Oct 13, 2006.

  1. JayGoldstein

    JayGoldstein Member

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    I've got 7,000 km (about 4,200 mi) on my car. I've noticed that every now and then, I can feel a momentary resistance as I'm turning the steering wheel. This only happens right after the car has started and it is either stationary, or moving very slowly (e.g., backing out of a parking spot).

    I know the Prius has its ideosyncracies. Is this one of them, or do I have an issue that needs to be brought to the attention of my dealer at the first service?
     
  2. qbee42

    qbee42 My other car is a boat

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    The steering on all cars is stiffer when you are not moving or moving slowly. I suspect that is what you are feeling, but it's hard to say with such a vague description. At slow speeds you can feel all of the irregularities in the pavement.

    Tom
     
  3. Tideland Prius

    Tideland Prius Moderator of the North
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    I'll be bold and say it's normal. It's the way the electric power steering works.

    Try this experiment: (always keep the car moving so you don't wear the tyres down)

    Rotate the steering wheel one way to full lock, then try rotating it the other way (e.g. doing a 3 point turn). When rotating it "the other way", you'll feel a strong resistance. I assume that's the same type you're talking about. So it is normal.
     
  4. tumbleweed

    tumbleweed Senior Member

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    I agree with the other two, I think it may be normal. Depends on how much resistance you are feeling, a little is normal. See if you can find another Prius to drive and see if it does the same thing, or let another Prius owner drive your car.
     
  5. JayGoldstein

    JayGoldstein Member

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    <div class='quotetop'>QUOTE(Tideland Prius @ Oct 13 2006, 03:40 PM) [snapback]332471[/snapback]</div>
    Describing something you "feel" in the steering is tough. The momentary "resistance" I feel is not when the steering wheel is at full lock (I'm familiar with that sensation). When it happens, it is during the first 360 degrees of steering wheel rotation to the left or right (with the car stationary or moving very slowly). The best way I can describe it is that for a split second it feels like the steering stiffens/binds slightly, and then feels normal.

    As I mentioned in my original message, since this only has happened when moving off right after the car engine has started, I'm wondering if it has anything to with an increase in pressure in the power steering. Obviously, I need to learn more about how the Prius' power steering works.
     
  6. galaxee

    galaxee mostly benevolent

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    if you feel it when you first start turning the wheel, it's normal. partway through the turn, might not be normal. in that case, ask about it at your service visit.

    when you first start to make a turn, power assist doesn't kick on immediately, there is a brief hesitation while the torque angle sensors start to read torsion applied, signal is sent to the power steering ecu, which controls the assist motor.
     
  7. JayGoldstein

    JayGoldstein Member

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    <div class='quotetop'>QUOTE(galaxee @ Oct 13 2006, 09:35 PM) [snapback]332580[/snapback]</div>
    Let me try to do a better job of describing the condition about which I'm concerned. What I'm noticing sometimes is a slight "knock" that can be felt through the steering wheel as the wheel is turned quickly while the car is stationary or moving very slowly.

    I mentioned the above at the first service visit. Unfortunately, as seems to be typical with intermittent issues, the technician couldn't duplicate the behaviour, so nothing was done.

    Now that overnight temperature are below 0C (32F), I've experienced the following on two occasions:
    1) the car has been sitting overnight,
    2) as soon as the Ready light comes on, I shift into Reverse and slowly back up using only the electric motor, and
    3) a second or two later, the ICE starts, and simultaneously I can feel the "knock".

    I'm curious about whether anyone else's Prius exhibits the same behaviour as mine.
     
  8. pinball

    pinball New Member

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    It might be the suspension settling ?
    Is it only first thing in the morning ?

    But if you are feeling a 'knock' or 'kink' as you turn the wheel ( ie a moment's resistance) then you need to get it checked out by your dealer.
    Mine is smooth from lock to lock - although at very low speed it requires more effort (ie 3 point turn.)
    The important thing is to be able to show the dealer.

    Have you had your steering recall yet ?
     
  9. JayGoldstein

    JayGoldstein Member

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    <div class='quotetop'>QUOTE(pinball @ Nov 20 2006, 10:56 AM) [snapback]352087[/snapback]</div>
    No, the "knock" also can happen when the car is thoroughly warmed up.

    When I took the car in for the 8,000 km service, the first thing the service manager did was to see if there were any recalls/bulletins affecting my Prius. There were none.

    What were the symptoms (if any) of the steering problem that led to the recall?
     
  10. pinball

    pinball New Member

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    <div class='quotetop'>QUOTE(JayGoldstein @ Nov 20 2006, 04:33 PM) [snapback]352103[/snapback]</div>
    Here's the link to the Recall Thread on PC
    http://priuschat.com/Toyota-Prius-Special-...sue-t20240.html

    As far as I know there are no symptoms linked to the recall - its was just a Toyota driven initiative for models within a certain chassis range - I think any model that was recalled received a letter from Toyota first.
    I understood it was a just a precautionary measure though.
    I had to have mine done and it took two visits.

    As to the knock - I'd hazard a guess its suspension related as faulty shock absorbers 'knock'- however for a steering knock you should get down to the dealer - as long as you can demonstrate it at will, they can sort it out under warranty I hope.
    The only time I have felt a knock/kink on turning a steering wheel, was once on a Volvo I had and it turned out to be worn bushes on the steering linkage and once on my son's car after he kerbed it badly, really badly !
     
  11. cvstan

    cvstan Junior Member

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    I ran into someone who claimed that the Prius has a steer-by-wire system where the steering wheel is not mechanically connected to the wheels as in a "normal" car. I assume they are confused by the meaning of electric power steering. ???
     
  12. hobbit

    hobbit Senior Member

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    They are indeed. It's a mechanical linkage, just with the assist
    up near the wheel which is one reason the shaft gets more torque
    than you'd expect.
    .
    _H*
     
  13. carlisle

    carlisle New Member

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    <div class='quotetop'>QUOTE(CVS @ Nov 27 2006, 09:02 PM) [snapback]354641[/snapback]</div>
    Completely removal of any mechanical linkage between the steering rack and steering wheel sounds a bit alarming. Failsafe methods needs to be integrated with this one I guess. Well at least steer-by-wire means less weight and better flexibility in terms of design.
     
  14. hobbit

    hobbit Senior Member

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    crawl under the dash and *look* at the linkage...
    .
    _H*
     
  15. MarkR

    MarkR New Member

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    We get the same thing. I just put it down to the power steering fluid pressure building up for the first time and when it reaches set point there is a slight clunk as it starts to perform normally.

    Mark
     
  16. jayman

    jayman Senior Member

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    Jay

    Mine never does what you describe. Would it help if you could drive another Prius to compare??

    jay
     
  17. JayGoldstein

    JayGoldstein Member

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    <div class='quotetop'>QUOTE(jayman @ Nov 29 2006, 07:53 PM) [snapback]355495[/snapback]</div>
    The intermittent "knock" in the steering started at around 7,000 km, so it was completely smooth until then. If I could figure out a way to make the "knock" happen, I'd take it back to the dealer. Until then, I'll live with it.
     
  18. JayGoldstein

    JayGoldstein Member

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    Had the dealer look at the steering again (@11,100 km), but they couldn't replicate the "knock." According to the service manager, the tech checked out the steering and everything seems to be ok. However, just in case there is a problem with the steering shaft, he is going to replace it.

    It will take a couple of weeks the part to come in. I'm keeping my fingers crossed that this is the solution.
     
  19. vince31

    vince31 New Member

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    I've had the same thing on mine a couple of times. Mine is UK spec and 4000K. I first noticed it when reversing in the supermarket car park when I was shifting quickly from right lock to left lock. Not tried to reproduce it but will give it another go tomorrow. The only time I have felt something similar in a vehicle was when the power steering fluid was running low and the fluid flow could not keep up with the rate of steering input demand.

    Yep, had it again today. Just quickly turn the steering wheel left a complete turn and then quickly switch right and see what happens.
     
  20. JayGoldstein

    JayGoldstein Member

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    I think the solution has been found. :D Three days ago the intermediate steering shaft was replaced (@ 12,096 km), and I haven't felt the "knock" in the steering since. In fact, the steering feels noticeably more solid now.

    The technician reported on the work order that the cause of the noise was "intermediate steering shaft notchy." BTW, my car was not included in the steering shaft recall campaign.