Sunday, December 15, 2013

Adding Bluetooth A2DP Interface to the 2009/2010 GT-R

Because I have a 2009 Nissan GT-R, I feel that I am slave to the iPhone/iPod. I have wanted to dump my iPhone for a while now, but the 2009 & 2010 models only came with the iPod interface (if added as an option). This was back in the day that every car manufacturer thought that Apple was going to take over the world as the standard for all music devices.

I got an HTC One recently, and it works great in my Frontier Pro-4X with an aftermarket Pioneer stereo and also in my wife's new Q50; leaving the GT-R as the old dog. Well no more! There is a way to some freedom.
My Bluetooth A2DP Setup


I explored using multiple Apple 30 pin to bluetooth adapters (eBay and Amazon.com are flooded with them), but the issue is that they work well with home sound docks that pass analog audio signals but not digital audio devices that need to detect the Apple device and pass along serial commands and obtain song information. I have two of these units at home and they have brought my iHome docks back to life after Apple first changed the charging voltage from 12V to 5V and then later 30-pin to Lightning interface.

Being a good Apple citizen, I upgraded from iPhone 3GS to 4 to 5 and along with it kept modifying the GT-R's iPod Interface to support the devices. To date my setup to support the progression of Apple devices in the GT-R has been as follows:

Stock GT-R iPod Cable in Glove Box (tucked behind glovebox) --> CableJive 12V to 5V 30-pin convertor --> CableJive 6 ft 30 pin extension for data and charge --> Apple 30-pin to Lightning Adapter.

This setup let me have the iPhone in the center console, with the cable long enough for me to charge and access the device up to my ear if needed. It also worked flawlessly in terms of not only allowing steering wheel but also song information display for control for iTunes, iTunes Match and also Pandora.

With the HTC One, I was dead in the water and frustrated. I explored upgrading the entire AV unit of the 2009 to 2011+ model and that would cost in excess of $6000 and require splicing 100's of connections. I did not want to start using the Car's HDD either as I prefer music from the Google Play cloud.

The other option was to modify the stock iPod Interface to accept non-iPod digital audio signals, which is a huge project in itself. As I was tracing the wires in that harness, it dawned up on me that when I first got my GT-R I had added my own Auxiliary Audio Video Input (DIY HERE) to allow for video playback in the GT-R that I do not use since the parking brake has to be engaged to view the video. I can easily by-pass this safety feature but had no interest in watching video.

So, I tested to see if the audio portion of the Auxiliary Input continued to operate without the video portion when the car was in motion. And it does! So Viola, I now have an Auxiliary Audio interface to tap into! I could simply plug into the headphone jack of the phone and deal power and audio on each end of the hone and also some phone cases not allowing it; instead I went with A2DP bluetooth receiver.

So for the expert user, I simply added an A2DP Bluetooth interface to the GT-R's Auxiliary AV input and I can now play audio via my HTC One or any device capable of A2DP audio straigh to the GT-R wand still use the stock GT-R bluetooth handsfree. Easy enough.

I still do not have AVRCP, therefore the steering wheel controls do no do anything other than volume and no media information is displayed, but in retrospect, I never liked using the GT-R interface to select music and really did not care about media information unless listening to a new Pandora station, which I rarely do. Also my screen is mostly not on Audio display, usually one of the function screens.

I will describe my setup and DIY install below. I simply modified my existing setup as described in the earlier link above and plugged into the Audio part of the AV interface, but I will describe how to build a new setup for those who may want to.

All I can conclude is that the Beats Audio from my HTC One over an A2DP Bluetooth is 95% as good as a direct digital iPod/iPhone connected to the GT-R. I am happy I have MY music in the GT-R and no longer a slave to Apple, just Google. ;)

Step 1: Purchase the Parts needed

- Nissan J-48817-127 Connector fro Nissan Parts Department:

- 8-10ft 3.5mm Audio Extension Cable - A good quality one like this.
- Belkin F8Z492TTP Bluetooth Audio Receiver (Link). The reason I chose this one was that it did NOT have batteries, which means that once the car is shut off, it shuts off too. It would be a bad idea to still have the phone still connected to the car while walking away from it. It also is not a cheapo knockoff that will need to be constantly re-paired or power cycled.
- Low Profile USB Charger (like this) so that it can fit in the center console, while providing power for both the Bluetooth Adapter and phone. It features a 2A output for quick charging tablets and such.
- Extra USB generic cable to make a power cable for the Bluetooth receiver.
- Soldering kit, tape, foam pieces, zip ties, etc.

Step 2: Make the audio interface cable

If you already have the AV input mod installed, then simply use this type of cable, which is what I did.

Otherwise...cut one end of the 3.5mm cable and strip the inner cables. I chose to put the bluetooth receiver in the center console, this allowed me to have access to it in case something went wrong without having to re-open paneling. Also, it allowed me to use the USB charger to power it rather than splicing a 12V car feed and trying to hook make a 12V to 5V rectifier. Keeps it simple and clean and fused. A little harder to install the first time though, but worth it.

Looking for from the side of the cables on the J48817-127 connector, the connections are as follows:



Pin 1 – Right Audio + (Inner from Red Cable of 3.5mm Audio Cable)
Pin 2 – Video + (DO NOT NEED TO CONNECT)
Pin 3 – Not Connected
Pin 4 – Not Connected
Pin 5 – Left Audio + (Inner of White Cable of 3.5mm Audio Cable)
Pin 6 – Right & Left Audio Ground (Outer of Red & White Cable of  3.55 Cable)
Pin 7 – Video ground (DO NOT NEED TO CONNECT)
Pin 8 – Not Connected

Solder the appropriate cables, cover them with heat shrink tubing or electrical tape. The net result should be a cable that has a J48817-127 connector on one end and a 3.5mm headphone connector on the other end and is 8 ft long.

Step 3: Modify the bluetooth receiver to increase bluetooth signal quality

The Belkin bluetooth receiver has a lead wight inside it to give it some substance, since I was going to have this in my center console which has enough metal all around it, I decided to get rid of the dead weight.

Using a small flat head screw driver, pry the top off the bluetooth receiver, this will break off the top cover as it is attached.
Remove the small electrical circuit board from the plastic tabs.
Remove the dead weight.
Re-install the circuit board.
Put the top cover back on, either simply use electrical tape around to hold the cover or superglue it back on.

Step 4: Make a USB 5V power adapter for the bluetooth receiver

I tried looking for one online, but they were to big to fit into the GT-R's center console.

I cut off the end of the stock 120V adapter that came with the bluetooth receiver and used a generic USB cable to make an 8-inch 5V power cable for bluetooth receiver.

The red wire from a USB cable is +5V and gets connected and soldered to the wire (of the original adapter) with the lettering. The black wire from the USB cable is the Ground and gets connected to the wire with the grey stipe.
The other 2 USB cable wires are data and simply get cut off. As per the picture below. This is the final cable to power up the bluetooth receiver.

Step 5: Quick test of the bluetooth receiver

Now would be a good time to test the unit to make sure the power cable is working.

I did this by powering up the bluetooth receiver via a generic USB charger. Then I paired it up with my phone. I plugged in a pair of 3.5mm earphones into the unit and ensured that I could hear the music streaming from my Phone via bluetooth.



Step 6: Install the Audio Interface Cable into the GT-R

This step requires removal of various panels.
Please see the post about making a Auxiliary AV Cable, here. Follow Step 5. 

At this point you should be able to plug in the audio auxiliary cable you made in Step 2 above to the connector. Hook it up to the bluetooth receiver, power everything and test everything at this point to make sure that it is working.  When the AV system is switched to AUX, and music is played over bluetooth, you should hear it :)

Now that everything is working, remove these items to help the routing of the cables.

Remove the 2 vertical finishing pieces on each side of the AV unit.

Remove the center console finisher by pulling it up at various points to release the tabs.

Remove the rear cup holder finisher. It doesn't come out completely as there is a G-sensor underneath it, you can either disconnect it or just leave it there to the site.

Remove the 4 screws that hold the center console cover and remove it.


I drilled a 1/2 hole thorough the back of the center console to pass the 3.5mm cable. A rubber grommet can be obtained from the local hardware store to seal up the hole.

Now route the 3.5mm end of the auxiliary cable from the back of the center console into the drilled hole.


Route the cable along the under the center console between the passengers seat and center console, tucking it in bit by bit. This is time consuming as there is little room. I had to move the seat forward then backward to reach various points.

Once the cable reaches the front, route it up next to the AV unit and run it along the back of the metal brace behind the dashboard and finally to the AUX connector in the harness.

This picture shows the route I took. Note I reused my aux connection, which you may not be doing, hence my picture looks different.


Use foam pieces, electrical tape, zip ties as necessary to secure the cable and ensure that it is not making direct contact with metal pieces that could damage it due to vibrations and rubbing.

Step 7: Install the bluetooth receiver and USB charger.

Now connect the USB adapter into the 12V power outlet in the center console

Connect up the bluetooth receiver and test it. It should work as follows:

Turn the GT-R is to ACC, and switch the AV mode is switched to AUX.

Stream audio from a Bluetooth A2DP device that has been paired up with the Belkin Bluetooth Receiver.

Audio should be heard from the speakers. If the handbrake is applied the screen should go blank as it switches to Video and upon releasing the handbrake it should briefly state that "Video will be resumed when vehicle stops" and then the message goes away.


The other big test I ran was having my phone paired up with BOTH the stock GT-R bluetooth handsfree and the new bluetooth audio receiver. When a call comes in, the audio switches from the music to handsfree and upon hanging up switches back to the audio receiver! Excellent! 

With my HTC One, I have noticed that the bluetooth receiver auto connects and auto plays music, and stops the track when the receiver is disconnected. This is great!

Step 8: Re-assembly of the panels.

Reassembly is reverse of removal.
Install the center console cover and 4 screw.
Replace the rear cup holder finisher.
Install the center console finisher.
Install the to vertical pieces that go on each side of the AV unit.
Reinstall the finisher with the vents
Reinstall the bottom finisher
Reinstall the lower finisher that goes behind the glove box, the connector for the trunk disable button and the glove box lamp connector. Put in the 10 screws.
Reinstall the plastic kick plate that covers the harnesses.
Reinstall the glove box and its cord.
Snap the door finisher and the door gasket.

Finished Product. Enjoy A2DP music in your GT-R without being tied to an i device.

The next step is researching and installing an interface that performs both A2DP and AVRCP so that I can not only control the audio, but also display information. Apple seems to have a stringent proprietary policy for compatible accessories.  Perhaps raspberry pi can help, but that is another project. : )