Steering wheel control issue

Discussion in 'Gen 3 Prius Accessories and Modifications' started by MagnusAG99, Aug 6, 2020.

  1. MagnusAG99

    MagnusAG99 Senior Member

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    So i have an issue with the steering wheel controls i just bought... Everything works, for the most part... The climate controls work, same does the radio, volume and all that. BUT, "trip" and "display" doesnt work, why is that? On the 3rd gen its also supposed to come up some hologram thing in the top screen when hovering over the buttons, and that doesnt appear either. Anyone know why? If it cant be fixed then i simply dont care, but if it can be fixed then why not fix it ya know. These are the controls i bought black button switch for Toyota Prius / Prius C / Aqua Steering wheel buttons phone cruise controller car accessories|Car Switches & Relays| - AliExpress . Its 10:15 pm here now so i dont wanna go out to the car again to open everything up again, but if anyone knows of a solution to this ill do it tomorrow.

    I see that it has one blue wire that goes to the bottom part of the airbag, what is that? It looks just like a ground wire... May that be what is incorrectly installed?
     
  2. ChapmanF

    ChapmanF Senior Member

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    Does your Prius have the "touch tracer" dash display, to begin with? Some trim levels did and some did not. The steering wheel buttons are not interchangeable.

    There are only a few wires that run from the steering wheel buttons to the car's electronics. In the non-touch-tracer cars, those wires are used directly to carry signals from pushed buttons.

    In the touch-tracer models, there are more signals to be carried over the same few wires (now it needs to carry not only which button you are pressing, but separately which button you are touching), and that was done by building a microcontroller into the steering wheel button assembly, and repurposing the wires as a digital data channel where the microcontroller sends messages about what you are pressing or touching, and the (different) receiver electronics in the dash decode the messages.

    Replacing some parts with the incompatible version might be one explanation for what you are seeing.
     
  3. MagnusAG99

    MagnusAG99 Senior Member

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    My car has that yea, pretty sure even the base Prius came with that in Europe. With the old buttons it all works. But not with the new ones. The tracer thing doesn’t work at all, “trip” and “disp” doesn’t work either... It seems to be the same amount of wires going into the car as well. It must be that it’s “the wrong version” I suppose then. But shouldn’t “trip” and “disp” work anyways?
     
  4. Shahzad Nayyar

    Shahzad Nayyar Junior Member

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    Looks like u need to change ur clockspring. It is a diy job and can take upto 30 - 60 mins depending on ur level of expertise and tools available

    Posted via the PriusChat mobile app.
     
  5. ChapmanF

    ChapmanF Senior Member

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    You can refer to this older post for more details.

    [​IMG]

    "the same amount of wires going into the car" is the key. How does the touch-tracer version send twice as many signals over the same amount of wires? By building a microcontroller into the steering wheel buttons, and redefining connection 9(A) from "TRIP" to IG power to the microcontroller, and 3(A) from "DISP" to a serial communication line for sending button status.

    Edit: if you get the correct button assembly and then you still don't have TRIP, DISP, or touch traces, get a meter and check that you still have +12V at 9(A) with the ignition on. As you can see from the diagram, if you had a non-TT version of the switches in there, you probably shorted that circuit to ground the first time you pressed TRIP. (Sorry I didn't save enough of that diagram to see which fuse that's coming from....)
     
    #5 ChapmanF, Aug 7, 2020
    Last edited: Aug 7, 2020
  6. MagnusAG99

    MagnusAG99 Senior Member

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    Clock spring was replaced 8 months ago by the Toyota Dealership here lol. What even does that and how does it relate to this issue im having? Is the clockspring "ground" or something like that?


    Mhm... May be that that micro controller does not exist in this aftermarket one then? But.... Didnt all prius`s come with the touch tracker? Here i know for a fact they all did, but did they in USA? If not, maybe its the ones sold in Asia that doesnt have it...
    But yea, since these controllers are for the 2012-2015 and i have a 2011 its probably not to bad that the tracer tracker doesnt work, because it would show the wrong button layout in the drivers display than the buttons im actually clicking. (since 2011 prius has the volume and change track buttons horizontal, same with the trip, disp and temperature. While the 2012-2015 has them vertical.).
    Ill test by putting in the old ones i have again and see if they work perfectly fine, if they do then its most likely that micro controller that doesnt exist in the ones i bought, right?.....
     
  7. ChapmanF

    ChapmanF Senior Member

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    Well, keep in mind what varies in that diagram. The wires shown with (*6) are present in the cars wired for touch-tracer, and the wires shown with (*7) are present in the the cars not wired for it.

    The steering buttons for a non-TT car indicate TRIP or DISP very simply, each one just pulls a wire to ground, connected directly to AU2 or AU1 on the combination meter, respectively.

    In a car wired for TT, one of those wires is +12V power instead, and the other one goes to the STRG terminal on combination meter, and transmits binary data to communicate which buttons are pressed.

    It's just not possible for either button assembly to work right in a car wired for the other kind.

    If you have a button assembly made for non-TT and use it in a TT-wired car, pressing the DISP button would just pull the communication line to ground (which probably won't hurt anything, but would be interpreted as a comm error, not a button press). Pressing the TRIP button would try to pull a +12V supply circuit to ground, which is not guaranteed to be free of consequence (such as a blown fuse or damaged button).
     
    #7 ChapmanF, Aug 10, 2020
    Last edited: Aug 10, 2020
  8. MagnusAG99

    MagnusAG99 Senior Member

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    interesting, kinda amazed how on almost no websites that sells these buttons knows this... What if someone who got no clue of what theyre doing just buys a used set of controls and its the wrong kind then damages the car... Does this say in the owners manual? Not even my local toyota dealer knew this when i asked them. Must be because those prius that does not have touch tracers was never sold here..
     
  9. ChapmanF

    ChapmanF Senior Member

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    It would probably be considered a bit on the esoteric side to include in an owner's manual.

    It's shown in the wiring diagram; probably Toyota assumes that will be reviewed by anyone who is thinking of replacing a part with anything other than what the dealer catalog pulls up for the car's VIN.

    They're probably optimistic in that assumption, but at the same time not unreasonable in making it. Manuals would get frightfully long if they had to detail all of the ways something could go wrong in mixing and matching non-original parts. It's kind of on the would-be mixer and matcher to figure that stuff out.
     
  10. MagnusAG99

    MagnusAG99 Senior Member

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    I guess, i get more amazed everyday by how packed of technology 10 yr old cars are...
     
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