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Old 05-27-2011, 06:07 PM   #18
Scooby Specialist
Member#: 25837
Join Date: Oct 2002
Chapter/Region: South East
Location: Atlanta, GA
1996 SVX L AWD
Laguna Blue Pearl


Yes, I've been a bit busy lately.


[Most information here is applicable to 2011, 2012, and 2013 models]

Originally Posted by SVXdc
  • Retaining steering wheel controls (SWCs):

    For most aftermarket HUs, you'll need a steering wheel interface module -- either the Axxess ASWC (by Metra), or one of the various SWI-* models from PAC Audio (SWI-PS, SWI-JACK, etc. -- different model depending on HU brand). More people prefer the ASWC. See this thread.

    Both the ASWC and PAC modules will "see" all of your steering wheel buttons (6 on older years, 8 on 2011-up with the extra phone/Bluetooth buttons). As far as the module is concerned, they're all just buttons. It doesn't care what the label says on each button.

    You program the module to determine what remote control command it sends to the HU. Each button can do any command that the HU supports.

    That last part is key: Many HUs don't have remote control commands that correspond to all of your wheel's phone buttons (even HUs that have built-in BT). It's a limitation of the HU itself. The HUs where the BT function is provided by an external module have been especially bad about not recognizing those commands.

    As 'first suby 2010' said, some HUs have commands for 'pick up' and 'hang up' and not 'PTT/voice recognition'. Others, vice-versa.

    According to Kenwood, 'call pickup' is the only BT-related function their HUs support via the wired remote port.

    You can program the ASWC or PAC module to assign any leftover buttons to do additional audio functions (e.g., Mute, Band, Seek Up, etc.), so none of your wheel's buttons need be "dead." The ASWC's automatic programming may assign audio functions to some or all of your phone/BT SWCs. If you want, you can go back and manually reprogram a button to do something different.

    Some older Eclipse HUs only understand 5 remote commands (volume up/down, track up/down, and mode -- no mute). So there's nothing you can do with your leftover SWC buttons in this case.

    A few HUs (some Eclipse models, and no-name Chinese HUs) can "learn" a car's SWCs -- they have the equivalent of a steering wheel interface module built in.

    Metra released a firmware update for the ASWC (on 2/23/2011). Their update notes include the comment "Added Kenwood, Sony, JVC, Alpine BT commands." Another entry dated 6/9/2011 has the comment "Added additional Bluetooth functions for Clarion, Kenwood, and Alpine." I don't know what exactly was changed or added, but if you have a module with older firmware, you might want to look into getting it updated. More recently, there was an update on 2/20/2012 that addressed "anomaly of random signals getting sent to the radio causing misc actions."

    As people mentioned, I make a 20-pin install harness (similar to Metra 70-7552 or Scosche NN04B) that includes the 2 or 3 SWC wires, so you don't have to splice into your factory wires. See my profile page for contact info (not PM).
  • Retaining OEM microphone:

    The factory mic in 2011-up models is in a small module with an amplifier circuit (see this thread). The module's audio output is not like an aftermarket HU's mic. Nobody has documented a good way to interface the OEM mic to an aftermarket HU. See this thread for one attempt.

    Unless you're especially skilled at electronics tinkering, you should plan on using the mic that comes with your new HU.
  • Factory aux input jack:

    I have been making an adapter harness to retain use of the factory 3.5mm stereo aux jack (in the armrest center console). I now have more of the parts needed to make those. See my profile page for contact info (not PM).

    If you'll be connecting an iPod, many recent HUs use an iPod interface cable that has both A/V and USB connections to the HU. See this post for issues to be aware of.
  • Factory USB jack:

    The factory USB harness has proprietary connectors at both ends. Pictures on the HU end here.

    UPDATED: Metra now makes a plug-and-play adapter, which connects to Subaru's proprietary plug (the one that was originally plugged into the back of the factory HU) and converts to a standard male USB 'A' (to plug into your new HU's rear USB socket). I have those adapters available.

    OLD TEXT, left for reference:
    Other options:

    1) Build your own adapter to plug into the HU end of the factory cable. See this thread and this thread. UPDATE: I now have some of the Hirose sockets and short USB cables available for you to assemble yourself. See my profile page for contact info (not PM).

    2) Build your own adapter to plug into the aux/USB pod itself. The USB socket on the back of the pod uses the same connector as several HU brands use for various external devices (CD changer, aux input adapter, etc.), though not the same pin-out as Subaru's USB, obviously. Picture of one example:
    The factory plug is right-angle too, so it looks like this aftermarket plug would work with the OEM aux pod. That picture is a Alpine KCA-121B aux adapter, but several brands use that same connector. UPDATE: I've taken a closer look at one of these Alpine aux adapters and found that it doesn't have metal contact pins in the right spots for the OEM 2011-up USB jack. It's possible one for a Sony HU uses different pins.

    3) Cut off the HU end and graft the factory harness onto your own USB plug. See this thread.

    4) Replace the OEM aux/USB pod with an alternate that has a normal USB "A" socket on the back. See my replies in this thread, and the thread I link to at the end.

    5) Remove the little circuit board from the OEM aux/USB pod, and mount the end of your new HU's USB cable inside the OEM pod (or remove the plug from one end of a USB patch cable and solder the cable to the OEM circuit board).
  • Dash kits:

    List of dash kit options for 2008-2011 Impreza/WRX/STI/OBS (plus 2012-2013 WRX and STi) and 2009-2013 Foresters.

    Note: 2012-up Impreza changed the dash. Aftermarket dash kits are now available for those models. You can hack one of the older kits and make it fit. See info and links in the above post.
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Last edited by SVXdc; 10-19-2013 at 12:10 AM. Reason: added PnP USB adapter; iPod cable issues
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