Anu2g

Hey all, I’m writing this post in hopes that it helps any one else looking to add Bluetooth Audio to their 981. I spent some time searching around for options and hadn’t found a straight DIY for a custom install, though it’s possible I missed one somewhere.

I just added Bluetooth audio to the base radio (no nav); I have a GT4 which comes with Sound Package Plus, but just the base head unit (I.e. no nav or any other upgrades). FYI, this unit does not give me bluetooth control. I wired it such that all wires are hidden, even if the glove compartment is opened; and the unit fully powers off when the car is not on.

Despite the number of steps listed below, this is a less than 1 hour job. It took me 3 hours just because it took me forever to figure out where to find “switched” power that was only ever on when the ignition was on. I don’t want the BT adapter to slowly drain my battery.

Items needed:

1) JL Audio MBT-RX (available online for $40); this is a BT module with a fused power wires, a ground wire, and male RCAs
2) Female RCA to male 3.5mm Y adapter ( )
3) Some spare wire to extend the power wire on the MBT-RX by about 3 feet
4) Wire stripper
5) Soldering iron + solder (optional)

Steps:

1) Extend the red power wire on the MBT-RX by 3 feet; I soldered the extra wire on.

2) Pull out the cig power port plate in the passenger glove compartment. To do this, I stuck a flat head into the slit to the right of the 3.5mm port and pulled; that lifted up the bottom right corner of the plate, at which point a stuck another smaller flat head under the bottom right corner. Then I just pulled with some force on the bottom right corner, and it popped right out. No broken clips. There is a good amount of space behind this plate.



3) Tap into the brown wire on the back of the cig power port, and connect the ground wire from the MBT-RX into that.

4) Pull out the 3.5mm port from the plate



5) Connect the Y adapter to the 3.5mm port.

6) Connect the MBT-RX’s RCAs to the Y adapter

6) Run the power wire from the MBT-RX through the area behind the cig port; you will be able to easily get the power wire sticking out of the back/bottom of the glove compartment and then just stick it under the the foam pad that you’ll see back there. Run that wire over to the passenger side fuse box


7) Stick the power wire into Row D, column 4; that is the ACC (Adaptive Cruise Control), an option I do not have. I have confirmed that this fuse is only on when the car’s ignition is on. This was important to me, as the power in the glove compartment stays on even after the car is turned off. The driver side has a whole bunch of extra fuses; you can grab one from there. The MBT-RX is already fused, FYI. I used a 7.5 but you could use a 5 as well.



8) Make sure everything works. It will show up in your bluetooth device list as MBT-RX. Set your radio to AUX.

9) Stick the MBT-RX and associated wires into the area behind the cig port; I rolled the wires up and zip tied them

10) Stick the cig port plate back on.

11) Enjoy!

Hopefully this helps some one. Feel free to leave feedback or ask questions.

-Anu

PS: Thanks to @12v Nick who gave me some guidance on this.

Treebeard

I think I may also have the "base" PCM unit in my 2016 Cayman S. I have no "media" or "source" buttons on the unit that are described in the PCM manual. I've found no option for bluetooth audio streaming on this PCM searching threads, etc. I purchased the Dension compact BT which allowing BT streaming audio through AUX but then had issues w/ bluetooth calls dropping/disconnecting so I deleted the Dension BT Source. Does this sound like the same PCM you have?

Anu2g

Sounds like the same PCM, but I don't have issues with calls dropping. I connect to the PCM for hands-free and the MBT-RX (in your case, Denison) for audio, and it works great.

Did you connect to the PCM for hands-free?

Treebeard

What happens is incoming calls seem to go to the Denison BT vs the Porsche PCM bluetooth. When I switch it to the correct PCM bluetooth source, the call drops and/or they can't hear me. When I call back on the Porsche PCM, it connects then drops. I deleted the Dension BT source, no more call issues. I think I'm going to look into your option - thanks for posting this !

Anu2g

My pleasure. On your phone's settings, you should be able to set your Denison to only be for audio, not hands-free, and then set your phone up to send hands free to PCM. Sounds like the problem is that your Denison is set up for hands-free. I'm pretty sure you should be able to debug this on your phone without replacing the BT module. Unless your Denison is only capable of hands-free, not audio only. I'm not familiar with Denison

Treebeard

I changed the Call Audio Routing setting to bluetooth headset on my Iphone X - it's on automatic by by default. This allowed the incoming call to come through the car speakers and not drop when I tested it. Unfortunately, I still have to select the car PCM bluetooth source when the call comes in, which is annoyinig, but it seems like calls aren't dropping now. I'm guessing you're an Android user - there's probably a setting to specify a bluetooth source to be hands free. Unfortunately the Iphone just has a list of bluetooth sources and no fine tuning options other than the accessibilty setting I just mentioned afaik. Thanks for your suggestion, I wouldn't have thought to look for that setting otherwise.

Virtualg

Thanks for the post and pics. I’m doing a similar install with a TP-Link BT module,

Question: How did you get the power lead out the back of the glovebox? I tried for 30 min to fish a lead through the opening where the stock cig lighter/aux cables go, but couldn’t get the fish tape/coat hanger to come through where I could grab it.

I’m just trying to rewire the cig lighter so it turns off w the car.

Thanks again

Anu2g

No problem. I fished it through that opening you're referring to, and then straight down (unlike the cig power which goes up somewhere). The wire should stick out of the left side of the bottom of the glovebox. I didn't use a hanger or anything, just my hands.

Once you get the wire hanging out of the bottom of the glove compartment, you can loosen the foam that is underneath the glovebox, and then stick it inside the foam, and run it towards the right.

Virtualg

Dies the JL audio unit beep when connecting or disconnecting?

Anu2g

I hear a beep through my speakers when I turn the car on, though I'm not 100% sure if this is related to my phone and/or Android Auto, or if it is specific to the JL unit. If it's helpful to you, I can test out a couple scenarios and get you a definitive answer.

Virtualg

Don't bother. Really appreciate the follow up. I'll be trying to fish the wire through on my set up later today. Hope I can get the wire to drop through like you were able to.

Anu2g

Feel free to DM me and I can give you my number if you want to talk it through while you're debugging

Virtualg

Thanks Anu2g for the tip on the wire feed.

Sorry to jump on your thread.

I wrapped up my install this afternoon.

Wish I'd found the JL bluetooth connector before I bought mine (this is my 2nd one, so I'm not buying another one). That JL module makes the install nice and clean.

I used a fuse tap in an unused slot that switched with the ignition.

Spliced in to the cig lighter adapter with the new tap from the fuse box.

Terminated the old power feed and removed the fuse just to be safe.

Now the connection turns on and off with the ignition. Previously, music would keep playing on my phone and the system didn't reconnect as reliably.

Here's my install:

Just need some shorter cables to clean up the glove box.


Fuse Tap in slot 2. Moved 20A fuse for cig lighter from row 10 to blank spot.

Old power lead cut and terminated. New power lead on the left red/black.

New power lead connected to cig lighter adapter. Used a clamp connector to splice the 2 leads together. Easy to take back to stock if need be.

Panel reinstalled.

BT Adapter installed. Cable clean up next.
box.

Anu2g

Looks good. The JL unit is fused, so going to put a spade connector on the end of the wire that goes into the fuse box. How does your unit sound, by the way? I noticed that my audio through the JL bluetooth adapter actually sounded better than CDs playing through the head unit; that led me to conclude that JL's DAC (digital to analog converter) is much better than what is in the head unit. Otherwise, if both units had the same DAC, CDs would definitely sound better than bluetooth. I tested with the same tracks, by the way.

Virtualg

It sounds fine to me, and unless I upgrade the stock speakers, I don't know that I could detect any sound quality issues.

However, since i just got the car, I've only driven with the top and my right foot down. So, I'm not hearing much of anything but wind and the flat 6 .

The connection is great, very fast, great range, spec says 60 feet, but that's not necessary.

On paper, the JL should sound better since its using the aptx audio codec. The TP link is a2dp v 1.2.

However, I specifically wanted one that didn't have an audio indication when connecting.

All that said, I'll probably find another home for the TP link adapter and upgrade to the JL when I upgrade speakers, if I don't swap the head unit.

Cheers!