Saturday, July 30, 2011

08 Cayman S w/ Bose - Aftermarket Head Unit Upgrade (Pioneer Avic 120BT)

We did a head unit replacement in a Cayman S w/ Bose over the weekend with great success using the MOST HUR 997. So I will briefly go over the install in a moment.

Before I do so, I want to take a moment to address some of the questions I routinely answer regarding the different sound packages for Gen 1 and Gen 2, this pertains to both 987 (Boxster, S, Cayman, S) and 997 (all models). Also I want to briefly address some of the variations you may come across regarding Pioneer and Kenwood during wiring up the units.

Gen 1 9X7 Non Bose (Standard or Sound Package Plus)
If your car is standard equipped or you have the Sound Package Plus, installing an aftermarket radio is simply a head unit swap, no amp bypass or aftermarket amps required unless you want to. The harness adapter supplied with our kit includes the 8 pin speaker connection and also the amp turn on signal for the ASK amp in the Sound Package Plus. This install is relatively easy if you can follow instructions.

Gen 2 9X7 Non Bose (Standard or Sound Package Plus)
If your car is standard equipped or you have the Sound Package Plus, installing an aftermarket radio is simply a head unit swap, no amp bypass or aftermarket amps required unless you want to. The gen 2 adapter supplied with our kit includes the 8 pin speaker connection. For vehicles w/ the Sound Package Plus, the factory blue harness (part of the factory quad lock connector) has a white/red wire. The white/red wire is your amp turn on signal, it needs to be wire tapped in order to activate the ASK amp. This install is relatively easy if you can follow instructions.

Gen 1 and Gen 2 9X7 w/ Bose
If your car is equipped with the Bose Surround Sound System, you technically have 2 options when replacing the factory head unit.

Option 1 - Bypass the factory Bose amp
A harness adapter is available to connect to the speaker wire harness of the vehicle should you decide to go this route. An aftermarket amp is highly recommended. This install really should be done by a professional or an experienced installer.

Option 2 - Integration w/ the factory Bose amp
NAVTV MOST HUR is required to interface with the fiber optic signal input used by the Bose amp. This install is relatively easy if you can follow instructions.

Regarding the variations between head units, as it pertains to the harness adapters. Pioneer seem to have done away with a dedicated Power Antenna wire in their newer model head units. Your vehicle however still has a power antenna wire as part of the factory harness, so in order to provide the signal for the power antenna, the "System Remote Turn On" wire which is used to switch the factory amp (or an aftermarket amp) must also be connected to the power antenna. This will allow A.M. reception in most cases unless you live in a very rural area.

In reference to the Kenwood units, many of them today do not have a VSS (Vehicle Speed Signal) wire, so it is simply not addressed during the installation. If you have any particular questions you would like addressed, feel free to contact

Below is conceptually how you would do an amp bypass on a vehicle w/ Bose set up. It's a bit more complicated than that but just a visual to help make sense of everything. A diagram w/ color codes is also provided below to show the different color wires associated with the Bose harness adapter provided to avoid splicing the speaker wires during the amp bypass.

On to the install using the MOST HUR. I will post the parts in the kit used and then discuss what was needed to be done to the car and the head unit. Then I will discuss how it works, the sound quality and some of the things you should be aware of when using the module.

From right to left, the first picture is the premium kit we offer for those that want to keep the entire Bose system intact, it includes many parts of our standard kit along with the MOST HUR components.

The second picture is the modified harnesses we include with the premium kit. The black harness is stripped of any unnecessary wires to minimize clutter. Leaving only 3 wires that will connect to the vehicle's 8 pin connector for ground, battery and power antenna. The salmon colored harness is something we took from our 9X6 kit, stripped it of all the RCA wires, leaving it with 2 wires to address CAN Hi and CAN Low.

The last picture is the MOST HUR itself. While it may seem somewhat complicated, it is a very simple device to use. I will explain how it works and how the harness adapters we provide (picture 2) works together for a very seamless integration with little to no splicing whatsoever.
First, we will do some preliminary wiring. This part is very simple, especially if you just follow the instructions provided below.

The bulk of the wiring connections made are actually from the head unit to the MOST HUR wires.

1. Head unit RCA cables to MOST HUR connection cable: Connect Front & Rear RCA Outputs to corresponding RCA's of the connection cable of the MOST HUR (Red RCA is the right channel, and White RCA is the left channel)

2. Head unit wires to MOST HUR connection cable: Connect VSS to pin 16(green/white), ILL to pin 8 (Orange), Parking Brake to pin 15 (Green), System Remote to pin 5 (yellow/black), Reverse Signal to pin 7 (purple/white), IR Control to pin 14 (white) (IR Control is only supported if you have Kenwood or Alpine and also if your vehicle has steering wheel controls), Accessory Signal to pin 17 (red)...the pin locations referenced above correspond to the wires of the connection cable. (Only exception is if your vehicle is a manual, you will need to tap the reverse signal from the rear tail lamp since CAN bus does not provide this signal for standard transmission vehicles). If you plan to do the parking brake bypass modification, then you simply will not address the Parking brake wire of the module. Same thing goes for any wires not relevant to your head unit, such as the IR signal, you will simply not address them if they're not needed.

Next, we make the connections w/ the harness adapters supplied in the EMS kit.

1. We take the 12v constant (battery) wire from the head unit and connect  to the 16 pin black harness adapter's yellow wire.

2. We take the ground wire from the head unit, along with the ground wire (pin 10) from the MOST HUR connection cable and connect BOTH of those wires to the 16 pin black harness adapter's black wire.

3. We then take the power antenna (blue) wire from the 16 pin black harness adapter and connect to the System Remote wire of the Pioneer 120BT. (This is specific to recent Pioneer head units, your head unit depending on the manufacturer may have a dedicated Power Antenna wire)

4. The salmon color harness adapter then connects to the CAN Hi and CAN Low wires of the MOST HUR connection cable.
a. Purple wire (CAN Hi) of the salmon color harness adapter connects to brown wire (pin 18) on the MOST HUR connection cable.
b. Green wire (CAN Low) of the salmon color harness adapter connects to brown/red wire (pin 9) on the MOST HUR connection cable.

Note: Only a few wires (5 wires plus the fiber optic connection) from the connection cable and the head unit are connected to the vehicle using the supplied harness adapters - allowing you to avoid splicing any wires in most cases.

The pictures below show the factory harnesses we will plug into the harness adapters once we are ready to install the head unit. (We won't get into the details of radio removals, and some of the other procedures involved as this has already been covered by our previous DIY, which we go into great depths about things such as disconnecting the ground cable of your battery before you begin work on the radio installation).

From left to right, the first picture is the 8 pin factory harness which will supply battery, ground and connects to power antenna.

The second picture, we have the 8 pin factory harness plugged into our harness adapter.

The third picture is the factory harness which includes the 6 pin C1 plug which provides access to CAN Hi and CAN Low.

The fourth picture shows the CAN Hi and CAN Low harness plugged into our harness adapter.

Once the factory harnesses are connected to our harness adapters, we will also take the fiber optic extension cable supplied by NAVTV and connect it with the fiber optic cable of the vehicle.

We then route the MOST HUR connection cable and the fiber optic extension cable down underneath the dash (behind the carpet panel). Here, we will connect the actual MOST HUR module. I prefer to place the module behind the dash or somewhere accessible as oppose to trying to fit everything behind the head unit which can be quite crammed.

We then connect all the necessary plugs into the head unit, reconnect the ground cable of the battery, test to make sure everything is properly working, and finally put everything back together.

 So here are the benefits I see with using the MOST HUR.

1. Installation is considerably more simple and less labor intensive. In most cases, many of the signal wires (Illumination, VSS, Parking Brake, Accessory Signal, Reverse Signal, System Remote) of the head unit receive signals through the module via the CAN Hi and CAN Low connection to the vehicle, eliminating running a lot of wires/RCAs in the amp bypass method.

2. No alternator whines or noise feeds. This is probably one of the greatest advantages over using an aftermarket amp. With an aftermarket amp set up, if you have a humming or whine...the agonizing part is trying to isolate the source of that noise or interference. Reading other members who've gone this route, I know it can be sometimes frustrating to troubleshoot this issue. Using the MOST HUR, the digital sound sent through fiber optic cables do not pick up noise interference when transmitting to the Bose amp.

3. In most cases, very little to no wires are spliced in the process. So returning to stock simply means pulling out the aftermarket radio, unplug the harnesses and reconnect the original head unit. (All of our kits are in fact designed to be minimally invasive, and includes parts designed to integrate as much as possible to your factory set up.)

4. This is going to be depending on your stereo budget, but for the vast majority of people the MOST HUR will provide an improved and more than satisfactory experience w/ your aftermarket head unit. The reason being, simply is that radio manufacturers such as Pioneer, Kenwood, etc. do provide a premium radio in comparison to the stock unit. With aftermarket radios, your going to get improved sound quality and more powerful output compared to stock. Furthermore, the various equalizer settings on these aftermarket head units really help fine tune what you hear to your preference.

5. All of the speakers remains in use in a very simple set up versus trying to figure out different methods to address the various speakers and the self powered sub when bypassing the amp.

As you can probably tell, I really like installing using this method now that I have had a chance to do one locally. It was technically a breeze to install, and I didn't have to do much wiring to get everything to simply work and worked great to be quite honest. Below are some pics of the finished product. Not really much different from any of our other installation pics but it's my most recent pics, enjoy. If anyone is interested in going this route or have questions, feel free to contact us by phone or email.

Kind Regards,

877.408.EURO (3876)

1 comment:

  1. Excellent article on upgrading the Porsche head unit and far less involved than replacing the amp and speakers. This should be attractive to more Porsche owners than the more expense alternatives and without any negatives.