Use OEM Mic with Aftermarket Headunit

I ran across a thread on another Toyota forum about how to use the OEM mic with an aftermarket headunit. You don't have to use the 28 pin wiring harness extension that I used. Because I have a Linkedin headunit, which came with matching plugs, I didn't want to compromise the existing wiring of the Linkswell or the truck. If you choose to use one, just search for '28Pin Wire Harness For Toyota Male To Female Extension Full Pins'. As for the USB and Microphone plugs (3.5mm or whatever your HU uses) that plug into the HU, you can use anything you have sitting around the house unused, which is what I did - there is nothing special about these. Just strip them and use the wires indicated below. The OP used a 100k resistor for noise reduction, but I did not (YMMV). Here is the harness which seems to be working well:
Here is the pinout for 28 plug harness:
Here are the connections to make:

Also, if you don't want to tie up a USB, you could use a 12v to 5v step down converter.

And if anyone does not want to mess with this, there is someone that is making and selling something similar: https://tombit.com/product/3rd-gen-toyota-tacoma-mic-adapter-atc-ato-fuse-type/

 

Bookmarked and probably tackling this someday.

 

I thought the issue was the factory mic was amplified and needs a 5v signal. Do you not need voltage to the factory mic and just need the pin 5/19 mic leads tied into a 3.5 plug? If this is true I’m doing this ASAP.

 

That's what the USB supplies, the Mic +5v signal.

 

Bookmarked

 

Gotcha. I started looking at my HU and I see an external storage USB plug. Need to confirm if it’s powered or if I need to draw voltage from the HU fuse(add-a-fuse) and then step down voltage. Don’t want to tie into the phone link usb port and mess with the carplay link.

Thanks a ton.

 

The USBs on the back of your HU will definitely provide the 5v power, but depending on the port, you might get an error about "incompatible USB" or something along those lines. Probably not a bad idea to use the step down kit like you mentioned.

 

The USB power standard is 5v. If all you are using the USB port is for power (ie just using the 2 power wires and not the data ones) then you are not going to get any kind of error - the HU won't even know it's being used.

 

Has anyone else done this and had it work? Everything else I find people act like it can't be done or you have to do alot more working taking about the factory mic/amplifier. This seems very simple.

 

I'll be hooking this up as soon as I get my truck back from the dealer. I have an idatalink maestro which has a 6v power supply for the reverse camera, so i'm wiring that to feed the mic preamp instead of using usb power.

 

This seems like a cool alternative to using an external mic. Has anyone who used this had any issues after long term use?

 

Only feedback (heh) I have so far using the amplified factory mic with a Kenwood carplay radio is that the person at the other end couldn't understand me, too much feedback.
So I think I need a little more tweaking

 

Ok. Thanks for the response. I wonder if the feedback is related to wire shielding. I think I’m going to give it a try since it doesn’t appear that the wiring harness is available at tombit.com anymore.

 

Did this for my idoing head unit in my 2015 corolla. Works great! CarPlay had no problems

 

I am getting ready to try this. Just an FYI. That diagram is not correct. It should be a 1K resistor and it goes on the MIC+ side, not the usb side.

 

I need this. Dasaita headunit is great in many aspects but the built-in mic ain't why.

 

Does anyone have a link to the harness they used? Is this how the 2nd gens are wired?

 

No idea about 2nd gens, but I bought this harness: https://www.ebay.com/itm/203459370351

 

Hah! I just bought the same thing for my own 2016, USPS says it arrives tomorrow. Let's compare notes when we're doing this up.

 

I made the cable. I’m going to test it tomorrow with my new head unit. I may end up ditching the usb and just hardwiring to a 12v to 5v step down converter tapped off one of the 12v plugs.

 

Get a chance to try it out? I also ordered in a 1k resistor to put mic-side for noise cleanup.

 

UPS lost my package. So Trail Grid Pro and UPS get to work that out while I wait even longer.

 

Ahhh yes, the standard UPS Manuever © - We Can't Incorrectly Deliver That Which We Lose ®

 

I've got mine assembled and the 1K resistor inline on the Mic+ so I'll use an AddAFuse to an accessory with a 5A fuse, and try mine out. My headunit is a Dasaita and I have Mic input gain control so if it's quiet, I'll be able to correct that, long as it's clean and comprehensible.

Also, you should sell yours along, recoup your costs if it's not going to work out for you!

 

Got some 1k resistors and put one in on the Mic+ side. I just tested with my friend and it was clear. They didn’t know which mic was which while testing. I tested it with both mics during the call. They picked the factory mic over the the mic that came with the head unit.

 

I ended up tapping the 12v plug closest to the driver using T-taps into a 12v to 5v USB converter to get power. I made a call, the mic still worked well, and I plugged in a 12v usb charger into the outlet I tapped and charged my iPhone from it as a test. Using the tapped outlet did not degrade the mic quality.

 

I tested mine out tonight and it's no different - I think I've missed a setting in the headunit, think it's still using the built-in "mic" on the screen, I'll do some tinkering with settings, see if I can't get it to switch over.

 

I have the same head unit (Sony 9500ES) and I used the mic that came with it and it works perfect and there is no problem hearing me on phone calls. There is a setting in the radio that lets you adjust the gain for the mic based on the size of the cab. I have mine set to large.

That being said I had for a short time a Phoenix Automotive Android radio that plugged right into the factory mic and you had an option to use the factory mic or the one built into the unit. The factory mic worked fine with that radio and didn't need any other harness that didn't come with the radio.

 

thanks. I ended up resolving this by putting in the 1K resistor. I now have the factory mic and the interior looks stock, other than the head unit.

 

Hardly even notice it.