Activating a factory CD Changer
 

I just purchased a factory 3198 CD Changer for my 1999 C280 and have a question about the installation process.

A Mercedes mechanic told me that it is not a simply "plug and play" process when installing a factory CD Changer because the head unit will not recognize the CD Changer until it is re-programmed.

Is this true? If so, is there anyway to re-program the head unit without taking it to a Mercedes Dealership.

The mechanic wanted over $200.00 to re-program the CD Changer.

Any help, guidance or assistance would be appreciated.

Most of the time it is P 'n' P. Find a new "mechanic".

I noticed on Ebay that someone was selling a MC3198 CD Changer and specifically mentioned in the ad that "dealer reporgramming" was not required, just plug and play.

I'm confused!

Why don't you just hook yours up and see. Then you'll know for sure.

I have a 2000 C280 Special Edition. The SE came with the CD Changer and Telephone options as part of the SE package. When I bought the car the CD Changer had been removed. I don't know why. I have tried to transfer the MC3198 from my 1999 E430, but the head unit shows the error "No CD Changer". My research has indicated that I may have to "version code" the HU. The document I found states that each component in the system must be added, in sequence, the the version code.

I would like to find some definitive instructions on this so I can figure out if the problem is just a coding issue or a problem.

On COMAND you do not have to re-code it - i think it is same for the other fibre optic head units in that generation of cars - i.e it just works. However, I suspect that what is wrong with yours is the fibre optic bus has to be physically reconfigured. The bus is in fact a loop, with a fibre going from the Transmit of one unit to the receive of the next and so on. That is why each unit has 2 fibres, one receive, one transmit.
If any item on the bus is disconnected, or fails, or loses power, then the whole fibre ring stops working and the head unit can see nothing.

So, when your CD changer was removed, the bus was physically reconfigured and therefore just plugging in new CD changer wont work.

I suspect the 2 fibres from the CD changer go to behind the head unit where they are just sitting - you will need a D2B joiner and to carefully open up the head unit fibre plug, swop one fibre with one that goes to the CD changer and connect the one removed to the other one that is left. Theres some info (but no pictures yet) at www.mercupgrades.com in the D2B info document.
To be sure you got the right fibre connector, stick a torch at the CD changer end shining into the connector !
If its not by the head unit, it may go to by the phone unit.


Regards
Richard

Richard - Thanks for the reply. I am aware of the D2B loop configuration. I pulled the HU. There is only one fiber plug and it is connected to the HU. I observed the fiber connector at the CD Changer and there are blinks at the red lens when I turn on the HU. My next step is to trace each fiber in the loop and check them with a "torch" (flashlight here in the US). From there I will check the "wake-up" cable. I recently noticed that the HU shows the error "No Phone" even though the phone is present and works from the handset.

Ok, if you are getting blinks then that fibre is connected, and the loop is broken and thus the phone doesnt work.

Adding the CD changer should make it all work again. I say that because if the fibre loop hasnt been reconfigured (and it hasnt) then its unlikely that the head unit was re-coded ... (although, to be fair, it sounds like your car is set up with one loop around the car, rather than a load of pairs going back to head-unit (or some other meeting point)
BUT, without the CD changer powered up, with its wakeup cable, then it still wont work.

Of course it could have been removed because something wasnt working, Its worth remembering that the phone controllers do fail as-well, and either unit broken will cause problems.

The phone controller (on euro cars) is normally in the trunk on left hand side behind the panelling (i.e in the space between boot liner and fender)

Cheers

Richard

Thanks again Richard - The D2B loop in my car is connected in series (sometimes called "daisy chain"). It doesn't work with the CD Changer installed, so I either have a failed component or a version coding problem, and that is what I am trying to sort out. I know the CD Changer is OK, so from here I will trace everything.

You should check the D2B wakeup signal aswell (blue/black cable) - all wakeup signals are spliced together in one of the front door sills - but if its broken/disconnected then some devices dont wake up. (i.e turn the fibre optic drivers on)

R