Porsche Telephone Preparation; 5 Year Mystery nearly RESOLVED

[RNajarian]

The following narrative is a description of my quest to hook up a handsfree telephone in my Cayenne. I am hesitant to splice into the fiber optic system, and since I'm still under warranty, I really don't want to risk voiding my warranty.

Of course I know I could have at any point thrown in the towel and had a professional do it . . . but that's not why we're Pelicans is it?


In '05 I customed ordered a Cayenne with telephone prep, $250. When the car came all I got was a black adapter bolted to passenger hand hold at center console. Dealer said "Porsche has run into problems with FCC regarding telephone sales and has suspended all phone prep."



I was told I would be contacted when the FCC issue was resolved.

After years of inquiry I was told by service rep only way to get phone capability was change out PCM head unit to one with sim drawer, $5000



In '05 when I first got FCC excuse from dealer I bought ( on Ebay) for $50 the entire hardware to equip an '04 Cayenne with mobile phone prep, but let it sit waiting for dealer to advise. I thought I could save some money on hardware using this used stuff. (Part numbers available if anyone wants to know). I was chicken to try it out because I didn't want to fry my PCM.

In January 2010 when I came across a tidbit on the net regarding the Porsche telephone preparation. Basically under the passenger seat of the Cayenne there is a pigtail used to hook up the telephone system. I dug out the old Ebay Porsche telephone hardware plugged it in to wiring harness, AND THE SYSTEM WORKED!!!!!

The radio mutes, PCM announces (visually) incoming call, and calls routed through car speakers. The microphone is even installed.

I had two problems however;

1) I could not find the antenna coax cable under passenger seat.
2) Who wants a hard wired cell phone to car (I would like to convert to bluetooth)

Using a wire connector which came with the telephone equipment I had bought on Ebay (also available from our host for $27.00 -Genuine Porsche Part: VDA SHORT CABLE PNA020004) I was able to convert the pigtail to the following connections;

1)Black -ground
2)Red -constant +12v
3)Blue -switched +12v
4)Yellow -PCM Mute

In addition I got a 2.5mm plug for the prewired microphone
and a 3.5mm plug for splicing into the audio system.

FIRST ATTEMPT
I plugged in the Porsche telephone hardwire phone system I had bought on Ebay. Next I purchased a Mercedes "Puck" which was a bluetooth adapter that connects into the hardwired vehicle phone system and convert it to a bluetooth system. The "Puck" powered up, in the Cayenne, paired with my bluetooth phone but did not interface with the Porsche Telephone system -STRIKE 1


SECOND ATTEMPT
Next I bought a Parrot LS 3200 handsfree kit from Amazon. I was hoping the wire leads from the PORSCHE VDA SHORT CABLE would allow me to easily hook up the hands free kit. The unit powered up but remained in constant mute. Took the unit to a professional installer and had him put it in my wife's Mercedes so it would not be a total loss, scored points with the wife but in relation to my Cayenne issue -STRIKE 2

THIRD (AND FINAL) ATTEMPT
Finally I bought a Motorola bluetooth kit ($40 off Ebay) and gave it one last shot . . . I wouldn't say it was a home-run but I definately got on base. Using the supplied microphone and speaker the unit works and properly mutes the radio. When I receive a call on the Motorola system hooked up to the pigtail under the passenger seat the radio mutes and the display shows EXTERNAL CALL while the call is in use. When I hang up it resumes the radio and the PCM display returns to normal.

My next step will to see if I can use the installed Porsche microphone and splice myself into the car speakers (using the VDA SHORT CABLE).

That is where I stand now. I will update you if I can use the installed Porsche Microphone and splice into the audio system using the two plugs that come off the VDA SHORT CABLE.

Stay Tuned for developments . . .

[RNajarian]

Here is a summary of what happened.

I successfully was able to use the +12V, Switched +12V, ground and Mute leads under the passenger seat to install an aftermarket Motorola bluetooth device.

I removed the plastic apparatus the factory stuck on the passenger hand hold (meant to house the original factory phone set up.)

The bluetooth control unit is about the size of a conventional flash drive so I put it between the shifter and the small square cubby near the armrest.

For now I put the microphone to the left of the ashtray cubby (ashtray delete in my case) against the passenger hand hold.

I'll do some driving tests to see where it gets the least static.

That's it. Having the telephone prep option made it easy to hook up. The only trick was getting the right bluetooth setup which would properly mute the radio. The Parrot Units I tried did NOT mute the radio.

If anyone is interested I can post photos.

[kishi23]

I would love to see pictures of this install!

[RNajarian]

OK my pleasure. Please give me a few days. I go under the knife tomorrow. (Old War injury -seriously)

I should have photos up by Thurs/Fri.

UPDATE TO INSTALL
The unit is working well but I am going to look and see if I can combine the Motorola Bluetooth WITH the Porsche Factory phone system to get the previously installed microphone to work.

[pilotsmith]

I hope you survived the surgery. Also looking forward to pics. Thx!

[Scott R]

I can't wait to see this, not having basic phone connectivity in my cayenne is really annoying. - subscribed

[RNajarian]

Sorry for the delay gang . . .

I will post photos tomorrow. I've been busy and haven't been able to do it.

Expect photos tomorrow (5/20/11)

[RNajarian]

Sorry for the delay but here are the photos from my install.

It must be noted that without the telephone prep option on my car this wouldn't be possible without removing the head unit.

First, here are photos of the Motorolla Bluetooth kit I used. $40 from Ebay.






Second is the dealer installed pigtail located under the passenger seat. To the right if that pigtail is the cable ysed to connect the wires, I did not want yo cut anything (available from our host for $27.00 -Genuine Porsche Part: VDA SHORT CABLE PNA020004)



Here is a close up of the short cable used to connect to the vehicle



I was unable to get the phone conversation to play through the vehicles stereo system. The hard wired factory system had a pre-amp that filtered/amplified the signal to get a clear sound. I gave up trying to figure how to do it so I used the Motorolla speaker included with the bluetooth kit to provide the sound. In this photo you see the speaker next to the bluetooth brain under the passenger seat.



The Cayenne Telephone prep also included an integrated microphone, which I could not get to work clearly either. The connection runs through the pre-amp, and didn't want to spend the time troubleshooting that either so I used the Motorolla microphone which came with the bluetooth kit and put it to the right of the ashtray. The sound is ok. Maybe when I get motivated I'll play with the pre-amp. As you can see I used double sided tape to affix the small control device near the shifter.





Finally, when a call is initiated or when a call comes in, the PCM mutes the radio and displays this on the screen




Overall it works pretty well, the advantage is NO wires are cut, the PCM does not need to be pulled out, and no panels need be removed. Of coutse, without the factory Telephone Prep option this won't work.

Hope the info is useful to someone