DIY: Retaining AND/OR Replacing OEM BT Mic with Aftermarket Headunit
 

So basically this DIY will accomplish 2 things

1) Retain your BT mic with an aftermarket radio (i.e. eliminate the need to run a new mic)

or

2) Replace your factory BT mic with an aftermarket mic for improved sound quality

Here's the factory mic, pulled down.

https://dl.dropboxusercontent.com/u/...2009.04.38.jpg

https://dl.dropboxusercontent.com/u/...2009.04.52.jpg

The wires you see are the left audio channel, right audio channel and ground. Yes, the OEM configuration is a stereo mic, not a mono mic...none of this matters.

1) Retain your BT mic with an aftermarket radio (i.e. eliminate the need to run a new mic)

In order to use the factory mic with an aftermarket unit you'll need an auxiliary cable, such as this one.

https://dl.dropboxusercontent.com/u/...2010.04.29.jpg

You'll want to cut one end off to reveal something that looks like this:

https://dl.dropboxusercontent.com/u/...2010.05.04.jpg

You'll want to solder the ends to some wire, I used wire that was the same color as the factory mic. The ground is the shielding and as far as getting the left and right channel correct, well it's a mic so it doesn't matter. Make sure you shrink wrap the wires and wrap them in electrical tape. It's not so much about electrical safety as it is preventing noise.

https://dl.dropboxusercontent.com/u/...2010.05.30.jpg

Now, here's where I don't have pics and it gets a little tricky.

Somewhere along the path from the mic, to behind the radio, where you'll ultimately connect the wires, the white wire from the mic, turns into black and the black wire turns into white. You will want to have your digital multi meter set to continuity so make sure you're tapping into the correct wires. The red/white/black wires you'll want to tap into are in the same plug as the vehicle speed sense wire, which is pink with a green stripe.

Once you have those tapped, you'll plug your auxiliary cable into your aftermarket head unit or if your bluetooth mic input on your aftermarket headunit needs a 2.5mm connection, use an adapter to take the 3.5 down to 2.5.

That's it! Your OEM mic is now your aftermarket mic.

After using the factory mic with my aftermarket unit, I realized how much the factory mic really sucks. I saw some posts on the forum discussing how the OEM mic was superior due to it being sealed in it's location, which is rubbish. Pull down your OEM mic and look at your headliner. There's no cushion or insulation, it's bare metal. So while using the OEM mic may work well for some, I ultimately decided to replace it. However, I have extreme OCD and I like the factory look. So I did not want another mic mounter anywhere other than the factory location. Here's how I accomplished that...

2) Replace your factory BT mic with an aftermarket mic for improved sound quality

Once you pull down the factory bluetooth mic you'll notice 2 tabs on each side, securing it to the housing. Simply push those tabs and the factory mic will release (no pics of this). You'll then take the OEM mic and push it up into the headliner. Afterall, if you ever go back to your OEM radio, you may want to use that mic, I don't know why but you might.

Now that you have your housing out, you'll want to position your aftermarket mic. I decided to go with a Pioneer mono aftermarket mic for mine.

https://dl.dropboxusercontent.com/u/...2010.03.04.jpg

Next, I took the mic housing and lined it with some thin pieces of weather stripping. The reason why is that the factory mic is square, but the aftermarket mics are circular. I wanted to give the mic some type of gasket and provide a clear channel to the mic.

I lined two sides with weather stripping. I placed the mic in the middle of the housing. I then lined the remaining sides with weather stripping. I then carefully placed a few dabs of hot glue on the sides of the housing to hold the mic securely but not to enter any of the noise canceling openings of the mic.

https://dl.dropboxusercontent.com/u/...2023.01.05.jpg

I then ran the wire for the mic down the passenger side and behind the radio to be plugged in.

The end result looks like this:

https://dl.dropboxusercontent.com/u/...2023.01.37.jpg

If you wanted to use an aftermarket mic for the factory head unit, then you'd purchase an aftermarket mic, cut the adapter off, do the same type of fitment as above and wire the mic (ground, left & right) directly into the factory mic connections either behind the radio or at the mic.

Voila! Done!

As an added bonus, not only does it look completely factory but it's completely reversible. If you want to go back to the OEM mic in the OEM housing, simply take a metal pick tool to pry away the glue, lift the mic out of the housing and press the OEM mic back in place.

This is a great writeup. I hoped to be able to do this when I upgraded the radio in my car.

Wow looks great!! how is the sound quality on the aftermarket mic? Can people hear you clearly when you talk on bluetooth? I just purchased a pioneer avic-x940bt and will be diy install in a couple weeks. I want to install the included mic where the oem is but I'm a little worried about sound quality. Any problems with removing passenger A pillars and putting the wire beside passenger side curtain airbag? :thanks:

I thought the OEM mic was powered, was that incorrect?

Incorrect

According to what wiring diagram?

All the diagrams I've viewed indicate the red wire is MACC, the black and white (which the OP has correctly indicated swap) are the sense lines for the Mic, and that there is no explicit ground line.

It would be fantastic if the OEM mic didn't require power, but that doesnt' seem to be the case as far as I can tell..

How did you go about routing the cable when you used the head unit's mic? If those wads at Toyota hadn't installed an amplified mic, or if they'd provide a wiring harness to make it work, then none of this would be necessary ;(

can you give me a link to the diagram your using.... do you know if the wire/s from the mic run all the way to the headunit?

I don't have a link to the full wiring (you can just google FR-S wiring diagram), but here's a screenshot of the mic wiring

http://i60.tinypic.com/14jua9e.png

Anyone have the pics to this thread?

Yes if someone could re-upload the pictures that would be great!

So 4 years later no one seems to want to post pics, sad! anyways so I am trying to install a pioneer AVIC-5200NEX into my 2017 BRZ. After many days of research and great posts by Akuma, Slopy and others (including this one) I have I think found a way to get the OEM mic. The pioneer mic input only requires a 2.5 mono input. Thus, based on the diagram below copied from Slopy on another thread, we can do the following connections:

http://www.ft86club.com/forums/attac...1&d=1454092563

I cut open my 2.5mm mono microphone cord that goes into the Pioneer, revealing the +/- wires... Pin 5 (Mic +) and Pin 19 (Mic -) of the 28 pin connector can be spliced into these. This leaves 3 wires due to the OEM being an amplified mic:

Pin 4: Mic power (5v)
Pin 6: Mic Detect
Pin 18: Mic Shield Ground (this should be easy and just tap into any chassis ground)

My theory is I can pull out the OEM HU and track where these 3 wires go, and just tap into those... this way we don't need to find out how the mic is detected AND we don't need another voltage converter (like we do for OEM backup cam retention).

Thoughts?

I'm hoping there is someone out there that will finally reply to all my posts because the 2017 is so much more work with the SWC too haha!

ALMOST THERE
 

[QUOTE=I cut open my 2.5mm mono microphone cord that goes into the Pioneer, revealing the +/- wires... Pin 5 (Mic +) and Pin 19 (Mic -) of the 28 pin connector can be spliced into these. This leaves 3 wires due to the OEM being an amplified mic:

Pin 4: Mic power (5v)
Pin 6: Mic Detect
Pin 18: Mic Shield Ground (this should be easy and just tap into any chassis ground)

My theory is I can pull out the OEM HU and track where these 3 wires go, and just tap into those... this way we don't need to find out how the mic is detected AND we don't need another voltage converter (like we do for OEM backup cam retention).

Thoughts?

I'm hoping there is someone out there that will finally reply to all my posts because the 2017 is so much more work with the SWC too haha![/QUOTE]

SO update. I went in and installed everything. Got the Reverse Cam, bluetooth and GPS working. Steering wheel controls will need a new solution (I tried the ASWC-1 from axxess but I am missing something I think)

OEM Microphone is all wired up EXCEPT I couldnt tap any wire in the dash for the mic amp power (5v) so I am going to buy another DROK step down converted (12 to 5) and just tap the ignition red wire and in theory that should work? haha

SUCCESS
 

So the back of a pioneer has 2 USB with power slots. I cut up a USB wire, deaded the data +/- wires, spliced the power+ (5v) wire to the pin 4 mic amp power, and sent the USB power- to chasis ground.

Worked like a charm!! If your head unit does not have USB slots in the back, I'm sure you can use a similar method to the reverse cam (12v to 5v converter, tap ignition 12v wire) for the same effect. So here is the FINAL pin arrangement that I can confirm works:

Pin 4: Mic power (5v) - Tap one of my HU's USB ports for 5V OR if you don't have a spare USB slot... Buy a DROK 12 to 5v converter and do similar things as you instructed with the reverse cam
Pin 5: (Mic +) - Positive wire of spliced 2.5mm mono that goes into HU
Pin 6: Mic Detect - I sent to chasis ground
Pin 18: Mic Shield Ground - I sent to chasis ground
Pin 19: (Mic -) - Negative wire of spliced 2.5mm mono that goes into HU

:thanks::party0030::happyanim: