Subject: Upgrade a 95 – 98 E38 non-nav Radio to get CD Changer iPod Integration Author: Brian (moderator) : member since January, 2005 : 8546 posts Posted on: 2006-07-12 21:41:29

This is a project write-up on the options to upgrade an early E38 radio to gain compatibility with an aftermarket CD changer or integrated iPod interface. Revjim and I completed this project on his 1997 740iL without navigation over the course of the last couple months. He did all the work, and I simply provided encouragement, troubleshooting, and system theory via phone and email. Unfortunately, I do not have any pictures to post, but they really are not that necessary.

BMW used the closed “PI-Bus” CD changer radio interface in the E38 from 1995 – 1998. Then, they changed to the open “I-Bus” CD changer in 1999 on. You can buy all kinds of aftermarket CD changer and iPod adapters for the later I-Bus radios, but no one makes a CD changer adapter for the early PI-Bus radios. So, most folks who want to get an aftermarket CD changer or iPod are forced to use an FM modulator or do some heavy duty internal wire splicing and soldering inside the radio module. You can also upgrade the car to a newer I-Bus radio, but that is not as straightforward as it sounds.

The challenge to the radio upgrade for a non-navigation car is that BMW made navigation standard in the US in 2000. Therefore, the only possible E38s that could have had an I-Bus, non-navigation radio were some of the 1999 model year cars. However, 1999 was a short run model year, therefore used 1999 radios are scarce on eBay and salvage yards. The other option is to upgrade to a comparable radio from a late E36 3 Series or Z3. If you do not have DSP, these radios plug in and work pretty well. If you do have DSP, then they radios work fine, but you need to change a few more things.

Following are a couple posts that discuss using an E36 3 Series and Z3 radios. The three options are the C33, C43, and CD43 radio. The C33 is the 1st generation radio, and it is pretty much junk, so do not even bother with one of those. Revjim first bought a C33 radio, and returned it within a day. It sounds inferior to the stock E38 radio, and they have notorious pixel problems. The C43 radio is a very nice cassette radio with RDS & PTY (another upgrade over the pre-99 E38 radio). The CD43 radio is the real sweetheart. That one has in-dash CD player, which is a major upgrade. Revjim went with the C43 radio, because he did not care about in-dash CD, and it sounds better than his stock E38 radio.

http://www.bimmerboard.com/forums/posts/192508/
http://www.cardomain.com/ride/433594/17

So, when you install one of these radios, a few things will change.

* Your original CD changer will no longer work, because the radio is trying to communicate over the I-Bus instead of your old CD changer’s PI-Bus. (This is OK, because that is the whole point of this upgrade.)
* If you have DSP, your DSP controller display will stop functioning. (This is semi-OK, because DSP equalizer settings are pretty much set-it-and-forget-it for most folks, and the DSP amp itself will continue to function just fine otherwise.)
* If you have DSP, your direct digital SPDIF connection between the CD changer and DSP amp will become inactive. (Again, this is OK, because your radio will just use the standard analog CD changer audio inputs instead.)
* You may get some alternator whine from the radio. (This is fixable, because BMW did an odd wiring hack in the many of the early model year cars that is easy to correct.)

So, off to the project…

Before you install the radio, inspect the radio plug. It may be missing two critical wiring pins for the ground signals between the radio and DSP amp. For some odd reason, BMW did not connect these wires at the radio plug, and spliced them to ground instead. I have identified a number of early E38 and E39 cars (including mine and revjim’s) that have this problem. This “floating ground” will cause alternator whine in with newer radios. Follow this post to inspect and fix the problem before you install the radio. http://www.bimmerboard.com/forums/posts/99394/

After you install the radio, give it a quick audio test. Everything ought to work perfectly except for the CD changer. Now it is time to move back to the trunk compartment, because you will need to create the wiring for the CD changer. The first thing that you need to do is create the 3-pin I-Bus plug. Buy these parts

61.13-0 006 663 CD Changer I-Bus Pin (0.75 mm²)—you will need 3 of these
61.13-8 377 072 CD Changer I-Bus Plug

And splice them into the following places:

Pin 1 Ground (splice into the brown wire on the original CD changer power plug)
Pin 2 Unswitched +12V (splice into the red wire on the original CD changer power plug)
Pin 3 I-Bus (white wire with gray stripe and yellow ringed bands. You can find it on the amp, phone, and other locations in the trunk)

After you create the I-Bus plug, you need to create the 6-pin analog audio CD changer plug. For this, you will modify the cable that led from your old CD changer to the radio. We cut the short 18” PI-Bus cable that connected from the CD changer on one end to the round DIN plug in the car on the other. Then, we spliced the audio wires inside that cable to the new CD changer audio source. The wires are in three groupings inside the short PI-Bus DIN cable. One of the groupings has a red wire and a white wire packaged together. This is the right channel analog audio. Another grouping has a green wire and yellow wire packaged together. This is the left audio channel. We did not use the third grouping. Splice the wires inside the PI-Bus DIN cable as follows:

Red: Right Audio +
White: Right Audio –
Green: Left Audio +
Yellow: Left Audio –

After you do the two trunk wiring hookups, you are done. Connect your new aftermarket CD changer or iPod, and rock on.

• Upgrade a 95 – 98 E38 non-nav Radio to get CD Changer iPod Integration (url) - Brian 2006-07-12 21:41:29 (5120 views)
  • Thank you Brian! You are a genius! - revjim 2006-07-12 22:58:35 (379 views)
    • Jim, pics, pics, pics!!! let's see the new radio & changer/ipod at work! (nt) - ljbimmers 2006-07-13 20:40:09 (486 views)
      • Re: Jim, pics, pics, pics!!! let's see the new radio & changer/ipod at work! - revjim 2006-07-14 17:12:17 (495 views)
    • Thank you guys! You've given me hope! (nt) - nbate 2006-07-13 00:43:18 (465 views)