Installing a CD Changer
on Your BMW
Wayne R. Dempsey

Difficulty Level: 4
Difficulty scale: Adding air to your tires is level one
Rebuilding a BMW Motor is level ten

[click to enlarge]

     When I bought one of my first E36 BMWs, I noticed it didn’t come with a CD changer installed. Knowing that all E36s are pre-wired from the factory for easy installation, I soon set out to find a unit that would work with my car and operate reliably. This proved to be a much more difficult task than I ever imagined. I gathered the information in this project from a host of confusing Internet sources. I believe it to be mostly accurate; however, some information directly contradicts other sources. At the same time, I have attempted to compile the latest information available from original BMW part numbers and documentation. To the best of my knowledge, the information here is accurate, but be forewarned—the BMW CD-changer saga is very confusing.

     In order to figure out what type of CD changer will work with your stock stereo, you will need to find out which stereo head unit you have. With the radio turned on, press down the “PROG” button along with the “MODE” or “Tuner” (-) button. The radio will then print out on its display the manufacturer name, and what version of the radio it is. The two original manufacturers of BMW radio head units were Pioneer and Alpine, so it will be one or the other. The number following the manufacturer typically corresponds to the model year of the car that the radio was made for.

     For example, the 1995 radio might say “ALPINE 5” when the buttons are pressed. (There are a few exceptions to this rule.  For example, the 318 from 1992 through 1996 all appear to have used the PIO2 head unit.)

     The 1989–1991 cars were fitted with a radio head unit that used a 13-pin plug. The Pioneer head units (ke-83zbm) could control the aftermarket Pioneer CD changer, CDX-M30, without the use of an adapter cable. The Alpine radio head units (CM5908) could control the Alpine six-disc or 12-disc changers (Alpine part number TR-1600 and TR-1008). Attempting to use the Pioneer changer with an Alpine unit (or vice versa), however, can result in damage to the units. Although the plugs on these units are identical, they do not use the same interface. Attempting to plug them together may result in short circuits and blown fuses.

     The 1991–1994 radios were outfitted with a 14-pin round data cable that is terminated in the rear trunk. The aftermarket Pioneer unit CDX-M30 can be installed in these vehicles with the addition of the BMWPIO/M adapter cable. With the adapter cable, these units can control any of the Alpine changers within this era and also the factory and aftermarket Pioneer units.

     In late 1994, the price of the BMW factory Pioneer changer unit was about $700 (Pioneer model CDX-M91ZBM), whereas the aftermarket units were about half that price (Pioneer model CDX-M30). It was much cheaper to forgo the factory unit and instead install the same Pioneer unit (with an BMWPIO/M adapter cable), than it was to purchase the option from the BMW dealer. So BMW changed the electronics interface in 1994/1995 so that the only changers that would work with the head unit were available exclusively from the dealer. As a result, if you have an “ALPINE 5” or a “PIONEER 4” head unit, it won’t work with the aftermarket Pioneer CD changers.

     The following is a summary of the radios and changers available from 1989–1995:

 
     In 1996, BMW again changed the interface used to control the CD changers. This later-style interface is called “IBUS,” whereas the earlier interface was known as “MBUS.” The IBUS and MBUS cars have different plugs and wires for the CD changers. The IBUS system is designed to connect the CD changer, the navigation system, MP3 players, etc. It’s fully expandable, and there’s even a group of loyal followers on Yahoo.com that have hacked the IBUS and written software so commands could be read by a laptop computer! In addition, there are interface adapter cables available that will convert IBUS, allowing you to install and use inexpensive and versatile aftermarket changers and MP3 players.

     When referring to the aftermarket Pioneer CD changers, it is also important to note that any “M” series changer will work. The Pioneer CDX-M30 is the last of the M series, and probably the most reliable unit available.

     There was also a Pioneer 12-disc unit that could be recognized and controlled by the early factory head units. You could cycle through each of the 12 discs by holding down each of the six buttons on the factory unit (holding down button number one loaded up disc seven). This aftermarket unit was never officially offered through BMW, but if you have a 1992 or 1993 radio head unit, it should be compatible.

     It’s important to note that BMW OEM Alpine CD changers all used an interface that was specific to BMW cars. None of the aftermarket Alpine units worked with BMW factory radios.

     Where is the pre-wired cable for the CD changer located? It seems the cable ends have been left all over the place, apparently depending upon the mood of the assembler in Germany at the time. They may be located under the back seat, near the rear speakers in the trunk, or all the way back in the taillight area. The power cable is a separate connector and is usually located underneath the carpet, near the right rear of the trunk area. Hunt around in this area—it will be located somewhere within the right rear quarter panel. The end is terminated with a three-pronged white plastic connector that should have only a red and brown wire attached. Some early production E36 sedans (four-door model) did not have the factory CD changer wiring preinstalled. In this case, the only way to get the CD changers to work properly would be to purchase the wire harness and install it yourself (not easy and not cheap, either).

     In those days, the CD changers were mounted on the upper right side of the trunk, just above the battery. There should be studs there that accept the factory mounting brackets. The CD changer for the E36 convertibles was mounted in the forward right part of the trunk, in a compartment that has a handle and rocks forward when opened. Depending upon which changer you have, and which year your car is, there appears to be a large assortment of brackets available. It’s best to try to pick up the brackets along with the changer if you purchase a used one.

     If you install your CD changer according to these guidelines and the head unit is not recognizing the changer, you may want to check the connections on the back of the head unit. Although the cars were supposed to be pre-wired from the factory, many times the CD changer data cable was not securely fastened to the rear of the radio head unit. Remove the head unit (see Project 88), and check the connections.

     If you can find one of the original OEM-style units that works with the factory radio head units, that’s only half the battle. I’ve spoken with many people, including some at stereo repair shops, who have had very negative experiences with some of the OEM units, in particular those manufactured by Alpine. For the pre-1996 cars, the newest of these units are more than 10 years old and often show their age. They break easily and are generally deemed unreliable. I’ve had three go bad in my cars over the years. Ailments range from refusing to give up the six-disc CD carrier to just plain refusing to acknowledge that there’s any power applied to the unit. From informal surveys, I have found the older Alpine units are not as reliable as the Pioneer units, many of which are still in operation today.

     My recommendations? If you have a 1996 or later BMW, there’s good news for you. The CD changers on the market for these cars are plentiful, and they are pretty reliable as well. New units are very easy to find that will simply plug in to the harness, will read burned discs, and will work flawlessly with the stock factory radio head unit (at a cost of about $250 or so). In addition, units from almost all other cars in the 1996–2004 BMW line will be interchangeable (3/5/7 Series, X5, Mini Cooper, etc.), which means a robust market for changers that were abandoned when owners upgraded their stereo systems.

     The only exceptions to this rule are the cars with in-dash navigation systems (NAV) and the 1996 318ti. In addition, there are new products out now from a company called Blitzsafe that plug directly into MP3 players such as the Apple iPod and allow you to tap the iPod directly into the head unit, as if it’s a CD changer.

     So what about the 1995 and earlier cars? Interestingly enough, at the time of this writing, the original Alpine and Pioneer CD changer kits appear to still be available from BMW (part number 82-11-1-468-014 and part number 82-11-1-467-700), although their price runs around $500 and $750, respectively. However, after messing around with CD players and changers in all my BMWs, I can honestly recommend that you ditch the OEM equipment and upgrade to a newer stereo and CD changer. A knowledgeable stereo storeowner who worked on these BMW systems all the time gave me this advice when I first started kicking around with trying to install the factory CD changers.

     I can say now that, after dealing with the older CD players breaking, and dealing with the problems installing and matching up the OEM units, I would take his advice and start over with the newer, better technology.

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