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Old 02-26-2012, 11:24 PM   #1
Scooby Newbie
Member#: 304175
Join Date: Dec 2011
Location: Richmond, VA
2012 WRX Limited

Thumbs up Pioneer AVH-P4400BH installed in 2012 WRX

Ladies and gents….installing a Pioneer AVH P4400-BH in a 2012 WRX, and retaining use of the factory steering wheel controls. (if you guys see anything that needs to be added here, please PM me and I will do so)

Here’s what you need.
1 Pioneer AVH P4400-BH (or similar H/U from the AVH series)
1 20 pin forward harness like the one found here. The harness on the link contains 3 wires not typically found in the harness supplied from many retailers like Crutchfield. You can either purchase from SVXdc, which I recommend because hi knowledge and customer service is second to none, or you can add the wires your self.
1 Axxess ASWC It can’t hurt to update the firmware before install. SVXdc can sell you one that is up to date at the time of sale. I lucked out and bought mine from Amazon and it was updated already to the latest and greatest firmware.
1 Dash kit. On my install I used the one supplied for “free” from Crutchfield. It’s Scosche part # SU2027B
1 parking brake bypass. These can be had for well under $10 bucks on ebay, or built yourself. This will allow full operation of, not only Bluetooth calling, but also, allow video to be played while the vehicle is in motion. While I don’t think it’s a good idea to watch video while driving, it is nice to have total control over Bluetooth calling while on the move. I don’t think it’s any worse than navigating through thousands of songs on an ipod while driving.

WIRING: First things first. Get everything wired. Wiring a car stereo is not brain surgery. Take your time, make good connections and take advantage of information like the stuff posted over at I was going to write a step by step on wiring the harnesses together, but it’s pointless when it can’t really be stated any better that SVXdc did on his site. Also on his site, specifically here , he lays out instructions for wiring in the ASWC. Please note that the colors in the instructions, variation “B” for the 2012 wrx, are specific to his harness and could vary if you build your own.
If you’re wiring in a bypass, you will need to connect this also. Mine has a green wire that goes to the light green Parking Brake signal wire on the Pioneer harness, a red accessory power wire, black ground, and blue remote wire that connects to the “remote” signal wire on the Pio harness.

DASH KIT: Putting a dash kit on a H/U is very simple, but there is an important bit to note if you are using the Scosche kit (part# SU2027B). There is a piece that frames the face of the H/U and 2 pieces that screw into the side of the H/U to hold it in place. The 2 side pieces hold to the front frame by 2 sort of tongue and groove slots on either side. Once this is assembled and slid over the front of the H/U, you need to screw it in to the chassis of the H/U. When doing so be sure to only partially tighten the screws on both sides. Once you have all of the screws installed, position the front face of the H/U within the frame so that there is a small gap on the top of the H/U and not the bottom. Now, finish tightening the screws. The gap in the front is not large enough to cause an aesthetic issue, but it is imperative for the 4400 to be able to open, close, and tilt properly. If you have a 3400, or another model that does not have a moving face there should be no worries regarding the gap I spoke of above.

DISMANTLING THE DASH: Ok, so now that you have a big nasty pile of wires, it’s time to rip apart your dash. It’s easy. I’ve seen instructions that show a guy taking off a whole lot of trim from the passenger side vent near the door all the way in to the H/U. This is unnecessary. Start at the bottom right corner of the light gray trim that surrounds the stock head unit, and if need be, using a panel removal tool or a wide flat tool (something that won’t scratch everything up!!) gently, but forcefully pry it up. A clip should pop out, then work your way up and around the trim and remove the whole thing. You can also do it without any tools as demonstrated by me below.
Now, with that set aside, there are 4 screws, marked by red arrows in the photo below (the photo was taken well after the install was complete, but the screw positions do not change with a factory or aftermarket H/U). Remove them, and be careful not to drop those suckers down in the opening. Now you have plenty of room to work. If you want even more room, unscrew the 2 screws, marked by yellow arrows, that hold in the last piece of HVAC ducting and that will pull right out. There is a plastic protrusion, circled in yellow, that helps line up the duct when reinstalling. (side note--I found removing the ducting helpful when I wanted to reprogram my ASWC. I was able to leave my H/U installed and still have good visibility of the red LED on the ASWC module.) Now, pull the factory H/U out and unplug the many wires from the rear of it. Booyah! The hard part is over.

WIRE ROUTING: Plug in your 20 pin harness, that has been connected to the ASWC, bypass and H/U harness, to the car’s harness. Figure out where you want to route your ipod cables, and bluetooth mic. I had originally intended to put my ipod in the center console, but as you will notice once you have the factory H/U removed, there is a very easy way to route the cable into the glove box without having to drill or worry about the open/close of the door being compromised. If you're mounting the mic on top of the steering column, its wire can be routed easily towards the steering column and up behind it without interference with the tilt/telescopic wheel function through an opening under the dash beside/behind the H/U. With the stock H/U removed, the path is easily seen. You might find it helpful to “stick” the wire to the plastic bits behind the steering wheel to eliminate any slack. I lucked out and had some cable clips left over from the CD-BTB200 bluetooth adapter that I had installed in a previous car.

INSTALLATION: Once your wires are routed and tucked where you want them, plug in the Pioneer harness and everything that needs to be plugged in (Bluetooth mic, USB cable, aux video cable, RCAs for amp, etc.) to the Pio H/U. Slide the H/U into place and replace the 4 screws to secure it (and the HVAC duct/screws if you removed them). Mount your bluetooth mic. This is a good time to program your ASWC to get on and off hook buttons to work before you button everything back up. Test it out and make sure everything works correctly. Replace the dash trim. Enjoy!

here's a photo of RockyMtnGT's set up. he's using the CDM/JDM dash surround with no open/close issues with the 4400:
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Last edited by slowhat; 03-12-2012 at 08:38 AM.
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