Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)

Installing bluetooth handsfree system in a 996 - How To

Recommended Posts

I just completed installing a bluetooth handsfree system in my 2003 C4S and wanted to do a write-up. I did a ton of research and most of the information and write-ups were from 2006-2007 and sparse. I wanted to record this so that if someone is searching for this in the future, they have something more recent to go by.

Requirements / Baseline:

  • Basically, my requirement/need was very simple. I wanted BT handsfree integrated into the car stereo - not external speaker. I wanted an external mic. I do not care about any of the other modern conveniences such as A2DP, Pandora etc.
  • The 2003 996's have MOST so that ruled out a simple head unit swap. I wanted to keep it all stock-looking so the Bose system and amp and speakers were a given. There were a few aftermarket BT systems manufactured during that time period that integrate with our stereos - Motorola and Parrot. The Motorola units are still available quite readily and can be IHF850, IHF1000 or IHF1700. IHF1700 is the latest.

Here are the parts I ordered:

  • Motorola IHF1700. I ordered an IHF1000 before I knew there was an updated model, but they actually shipped me an IHF1700. A google search revealed the IHF1700 was a very slight revision/update with "improved noise cancellation and echo control, along with a 50 number phone book" I ordered it from "CCMACCESSORIES" on Amazon. It was like $140 plus shipping. http://www.amazon.com/Pro-install-Car-IHF1700-Retail/dp/B0030BV7BM/ref=sr_1_1?s=wireless&ie=UTF8&qid=1381009957&sr=1-1&keywords=motorola+ihf1700
  • Vehicle-specific T-harness. I didn't want to splice any of the factory wires AND wanted the phone audio to play via the car speakers as opposed to the little external speaker that comes with the motorola kit. So I ordered a Becker CDR-23/24 harness that plugs right into the Motorola unit from "discountcarstereo.com". It was $20 plus shipping. Part #: "BT-BKR23M Installation harness for Motorola Kits to Becker CDR23/24 Radios" http://www.discountcarstereo.com/BT-BKR23M.html
  • Wire splice connectors from Radioshack. More on this below.
  • Becker/porsche radio removal tool. I already had this from when I sent my head unit to Becker to get the Aux input wired in. I think I got it on eBay for a couple bucks.

Installation Notes:

  • Installation of the Motorola unit is pretty straightforward. I installed the mic up top near the dome light - my previous experience in other cars as well as research indicated that other possible mounting locations were noisier. I routed the wire through the headliner, a-pillar and down under the steering wheel console to the center console where I put all the wire bundles as well as the motorola system's control unit.
  • I installed the Motorola Interface Control Module in the bottom of the center console. Ran the wire underneath.

Speed bumps / Hiccups:

  • Make sure to read the attached instructions (PDF attachment to this post) from discountcarstereo on where the green connector plugs into the "C2" slot behind the Becker. I didn't and it took me a bit of time to figure it out.
  • This next item took me over a day to figure out, with help from a wonderful gentleman at discountcarstereo (their customer service was awesome, he kept emailing me back and forth over the weekend and reviewing photos I sent him). The Motorola unit needs two 12V power input lines - one switched and one constant. This is so that when you are on the BT and turn off the car, it will keep power so you can finish the conversation. The unit wont power on unless you have both power lines connected.
  • Here's the kicker. If your car has a digital amp, the switched 12V line from the t-harness will be blank (on the factory harness side). So, you have to run a separate 12V switched line. I chose to do it from the smartphone connector down in the center console and spliced into the discountcarstereo harness, thereby leaving all the factory wiring intact and untouched.
  • Once you get that figured out, you have to change settings on the CDR-23 head unit - again, read the instructions in the attached PDF.
  • The Motorola wire bundle contains two in-line fuse holders with 5 amp fuses in them. These things are very very cheap/flimsy and someone from a 2006/2007 VW thread also complained of the same. They were causing a spotty connection. So I unclipped both ends of the fuse holder, stripped the wire ends, overlapped them a bit, crimped the ends of the metal connectors and assembled them back. If you have better quality inline fuses laying around, I would recommend swapping them entirely. I didn't, so I fixed the ones supplied.

Here are some of the "features" of this setup:

  • I set the volume out to be from the driver's side front speaker (you can have it play only on one speaker - my old E46 M3 was the same, so must be a period thing from the early BT systems). This is done from the CDR-23 head unit's settings menu.
  • "Wake up on phone audio" this feature was a complete pleasant surprise. Made my day. Basically, in modern cars, even when the stereo is switched off, when you get a phone call, the stereo will wake up and play the phone audio via the car speakers. I was expecting the motorola unit to not have this feature. But it does!! So, both incoming and outgoing calls will wake up the Bose head unit which will say "Phone" and the call audio will play via the car speaker.
  • Phone volume can be adjusted via the bose unit. Very nice.
  • When you get in the car and turn on the ignition, the unit automatically pairs with the phone (can pair with upto two phones) and announces (via the car speaker) "phone connected"

I was warned that road noise at highway speeds is pretty high in our cars so the mic will not have very good clarity. I have not tested the sound quality extensively yet and will post an update over the next weeks after I have used it in various conditions. Here are the photos of the install. Special thanks to "Dennis C" on 6speedonline for sharing his experiences from the IHF1000 kit. Want to thank the tech support person/team at discountcarstereo again, I wouldn't have been able to figure it out if they hadn't helped.


I have had a chance to test this setup over the past week both around town as well as on the highway.

  • The microphone is excellent. Everyone I spoke with said my voice was very clear and legible even at highway speeds. Definite + for mounting it up on the dome light console.
  • Everyone complained of a crazy echo problem - they could hear themselves. I moved the mic back on the dome console, didn't solve it. Routed the audio to the right side speaker instead of driver-side. Didn't solve it.
  • I then realized that phone volume can be adjusted in two ways - via the Motorola unit and via the Bose head unit. At first, I had the Motorola unit's volume cranked up to max and the head unit volume low. This was causing the echo.
  • When I turned down the Motorola unit volume all the way down and the head unit up, the echo went away! The same folks now say the conversation is very clear.
  • After several weeks of using this setup to my satisfaction, I made the mistake of popping in a CD into the CDR-23 as well as the odd duck CD holder/tray thing. This threw everything off. the Bose unit started acting up - being stuck in the "Porsche" boot up screen. The Motorola unit was not sending any audio to the car speakers (was still connecting to the phone though).
  • I ejected all the CDs (and threw them away), took everything apart, and re-did the settings on the CDR-23 head unit (routing 'Mono', 'Stereo" and 'phone audio" all to the other speaker than previously selected) and everything is back to normal again. Just wanted to share this - the setup doesn't seem to play well with CDs, or it could be the CDR-23 is not playing CDs anymore. Either way, not a loss for me (who the heck plays CDs anymore anyway?!)









Edited by xxaarraa
Link to comment
Share on other sites

  • 3 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.