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Can Techstream make steering wheel straight ?

Discussion in 'Gen 3 Prius Technical Discussion' started by Buderim, Feb 28, 2020.

  1. Buderim

    Buderim Junior Member

    Joined:
    Jul 22, 2017
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    Location:
    Queensland Australia
    Vehicle:
    2010 Prius
    Model:
    i-Tech
    I am in Australia and have a 2010 Prius i-tech which is the high end one with solar roof , reverse camera and self parking with standard 15" wheels and tyres. The steering wheel was fine until the tyre change.

    I have a problem with the steering wheel being slightly off center I had 2 new tyres put on the front and the wheels aligned as I had slightly uneven wear on the inside of the tyre , the company I used is a big tyre chain and and have decent machines and fitters. When I picked up the car the steering wheel was a few degrees to the left , so after a few weeks I took it back and asked them to make the steering wheel straight it which they told me they did.

    When i drove home the wheel was still off center exactly as it was when I took the car in. So I put a crap review up for them , next day the manager called me and told me to come back and they will get it fixed now here is the problem. They put it on the machine adjusted the tie rods and made the steering wheel straight which I saw , BUT as soon as you drive the car on a roadtest the steering wheel just goes back off center again . They adjusted it twice and it went off center again both times to the same off center position . I can only assume this must be connected to the self park system and the steering wheel is setting its self to what it thinks is center . I have tried using the self park to try and reset center but it has made no difference. Does any one know if you can reset the steering center using Techstream ? as I have no idea what to try next .
     
    #1 Buderim, Feb 28, 2020
  2. ChapmanF

    ChapmanF Senior Member

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    There is no way whatever for Techstream or the car's ECU to alter the lengths of the tie rods or their relationship to the steering wheel position. The ECU has calibration for the steering angle sensor, that's a sensor that tells the ECU which way the wheel is turned, which is useful for stability control and auto parking, but it's a sensor, it doesn't change where the wheels point. And the ECU can power the assist motor and turn the wheel, but again, that doesn't affect where 'centered' is.

    What I'm kind of saying is there might be some detail that isn't coming across in the exact way this story is being told.

    One condition that can lead to a story like this would be wear or looseness in some other part of the suspension, such as a ball joint, strut mount, or control arm bushings. The steering, by moving the tie rods in and out, is only precise because the pivot positions of the steering knuckles are held precisely in place by the strut mounts, ball joints, and control arms.

    If one of those can slip slightly forward or backward or side to side, it will, of course, change the alignment.

    Then again, one would kind of expect an alignment shop to check for that.
     
    #2 ChapmanF, Feb 28, 2020
  3. Buderim

    Buderim Junior Member

    Joined:
    Jul 22, 2017
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    Location:
    Queensland Australia
    Vehicle:
    2010 Prius
    Model:
    i-Tech
    Thanks for the reply , so in theory if I adjust the tie rods in accordance with this Toyota service builtin . it should put the steering wheel straight.

    EDIT , thats the wrong pdf
     

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    #3 Buderim, Feb 28, 2020
    Last edited: Feb 28, 2020
  4. Buderim

    Buderim Junior Member

    Joined:
    Jul 22, 2017
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    Location:
    Queensland Australia
    Vehicle:
    2010 Prius
    Model:
    i-Tech
    This is the bulletin I meant to post..
     

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    #4 Buderim, Feb 28, 2020
  5. 2012 Prius v wagon 3

    2012 Prius v wagon 3 Active Member

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    Location:
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    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Some things to think about ...

    Sometimes a defective tire can cause a pull to one side, regardless of alignment. An easy way to test that is to swap tires front to back and do a test drive. Swapping the two fronts with eachother will not do it.

    Forget the steering wheel for a minute. When you drive on flat ground, with hands off the wheel, does the car go straight? Where does the steering wheel go when you do that?

    Often it is a camber problem (not toe, which is the thing adjusted by the tie rods) that causes pull. So if you've got a pull, stop thinking about the tie rods and the steering wheel and start thinking about a camber issue, loose suspension part, or pulling tire.

    If the car was driving straight (no pull, steering wheel centered) when you went in there, no doubt at all they should get it that way again before asking for payment.
     
    #5 2012 Prius v wagon 3, Feb 28, 2020
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