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Prius 3 2014, SWC Cables

Discussion in 'Gen 3 Prius Audio and Electronics' started by StevieIreland, May 15, 2021.

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  1. StevieIreland

    StevieIreland Junior Member

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    Location:
    Scotland
    Vehicle:
    2014 Prius
    Model:
    Three


    I've successfully installed my new aftermarket head unit (Xtrons) and it's working great. I want to hook up the steering wheel controls.
    My head unit has "key1" and "key2" wires, which i believe I can hook up directly to white, black and red (gnd) cables on the Prius.
    My problem is, I've not seen any photos clearly identifying the Prius SWC cables, and I'd really like to know exactly what I'm cutting before I cut.
    I've attached the photos of what cables are available. I think I cut the head off the blue, white, black, red, yellow connect. Am I correct? Is that the SWC cable?

    Thanks!
     

    Attached Files:

    #1 StevieIreland, May 15, 2021
  2. Elektroingenieur

    Elektroingenieur Senior Member

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    Vehicle:
    2016 Prius
    Model:
    Three Touring
    Before you cut anything, I’d encourage you to review the edition of the Electrical Wiring Diagram (more info) that applies to your car, which identifies the connectors and wire colors.

    On U.S. and European Prius models for 2012–2015, the steering wheel controls for the audio system are brought to the head unit on three wires: SWG (pink), SW1 (red), and SW2 (green), typically wired to terminals 23, 21, and 22, respectively, of a 28-position connector, or in some cases, to terminals 6, 7, and 8, respectively, of a 20-position connector.

    The connectors seen in your photos all probably have other purposes, but it’s hard to say what they do without knowing which model you have. What’s the complete model code on the label affixed to the “B” pillar inside the left front door?
     
    #2 Elektroingenieur, May 15, 2021
  3. StevieIreland

    StevieIreland Junior Member

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    Vehicle:
    2014 Prius
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    Three
    Hi there,

    The car is recent import from Japan, so I'm trying to get used to it. I've attached that B Plate.

    I've also attached a photo of the head unit 20 pin diagram. Key1/key2 are numbers 2 and 3.

    There's no cables behind the head unit which match pink/yellow/green. So I'm stumped except to open the steering wheel and look at the wires inside.
     

    Attached Files:

    #3 StevieIreland, May 16, 2021
  4. StevieIreland

    StevieIreland Junior Member

    Joined:
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    Vehicle:
    2014 Prius
    Model:
    Three
    Here is the head unit diagram.
     

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    #4 StevieIreland, May 16, 2021
  5. Elektroingenieur

    Elektroingenieur Senior Member

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    Vehicle:
    2016 Prius
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    Three Touring
    The Japanese model is a bit different. What head unit was originally installed, and what connectors did it have? Were there any adapter cables between the vehicle wire harness and the head unit? Did the head unit have a 20-position or 28-position connector?
     
    #5 Elektroingenieur, May 16, 2021
  6. StevieIreland

    StevieIreland Junior Member

    Joined:
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    Location:
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    Vehicle:
    2014 Prius
    Model:
    Three
    Oooh, I really don't know. The head unit was changed before I bought it. The head unit I have has a 20 pin connector and what's in the Prius plugs right in, so I'd say 20 pin rather than 28. I don't see any adapters or anything.
    I feel terrible not being able to answer your questions.
    Any advice you can give regardless would still be appreciated.
    I'm thinking of adding a cruise control switch to the steering wheel, so maybe while I'm doing that job I can look at the SWC button wires while I'm doing that job. Do you think this is a good approach?
    Thanks again kind sir,
    Stevie
     
    #6 StevieIreland, May 16, 2021
  7. Elektroingenieur

    Elektroingenieur Senior Member

    Joined:
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    Vehicle:
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    Three Touring
    I don’t know if adding the switch is all that’s needed to enable cruise control on this model.

    For the head unit connections, if you could please post photos—along the lines of the ones in your post #1 above—of the other head unit connectors in the vehicle wire harness, showing the arrangement of terminals and the wire color for each one, it might be enough for me to identify the relevant wires.
     
    #7 Elektroingenieur, May 16, 2021
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