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Hijack Steering Wheel Buttons ?

Discussion in 'Gen 2 Prius Accessories & Modifications' started by SubPrius, Nov 3, 2014.

  1. SubPrius

    SubPrius Junior Member

    Joined:
    Jul 7, 2013
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    Vehicle:
    2005 Prius
    Model:
    II
    Can the buttons on the steering wheel be hijacked for other purposes?
    Does each button have a physical connector? Where are they? Does each button control +12v (on)?
     
    #1 SubPrius, Nov 3, 2014
  2. valde3

    valde3 Senior Member

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    Jun 28, 2014
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    Location:
    Finland
    Vehicle:
    2004 Prius
    No they (at least stereo buttons) work by changing resistance between two wires. Most of car stereo wired remote controls work like this. In Prius one wire is ground and you have two signal wires.

    Wire one has (at least) seek+, seek-, vol+ and vol-. They have resistances to ground:
    Nothing pressed more than 100Kohm
    seek+ less than 2.5ohm
    seek- about 0.3Kohm
    vol+ about 1Kohm
    vol- about 3.2Kohm

    Wire two has at least mode. They have resistances to ground:
    Nothing pressed more than 100Kohm
    mode less than 2.5ohm

    Simple circuit can be build that (for example) connects to wire one, ground and power and has separate outputs for seek+, seek-, vol+ and vol-. Connections are probably easiest to do behind stereo and you need to disconnect the wire from stereo since you dot want it to read buttons if you use them for something else.
     
    #2 valde3, Nov 4, 2014
    Last edited: Nov 4, 2014
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