Hey guys,

I am hoping someone has seen this before. My 2000 S430 Comand system produces no audio and displays "no cd changer". I am pretty good at troubleshooting most mechanical things but with the D2B system on this car I have no idea where to begin. I did test the amp for 12 volt across the fuse and the COMAND sytem fuctions as normal - just without sound. Does anyone have any ideas on where I might start looking?

Thanks!

Brian

Brian- i bought a new casette for the changer on ebay for 10 bucks. My changer is now recognized and everything works like it should.--JEFF

__________________
1999 C280 Sport, 1967 911s Porsche

Does the car have a phone or Voice control?
Do you have any Tele-aid faults showing?
Find the fuse chart in with the tools and pull out these
fuses. 18, 61, 63, 64, and 66.
Let the car sit for 20 min and put fuses back.
Hopefully the ring will reset and comeback.
If not, there is a hard fault with a D2B component.
We have a special tool at the dealer called the Berger Tester
that can be substituted for a suspect item.
It is basicly a D2B repeater.
Good Luck.
DR.D

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?

Thanks for the replies. It does have a phone and teleaid however no faults are showing. I pulled the comand unit and checked for the 4 light lock pulse. looked good and strong. Next I checked the 4 light pulse at the end of the fiber before the first D2B component. looked good. Then checked the light pulse after the first component. ok again. the next D2B component was the amp. I heard it click four times but no light exiting the amp fiber. I strongly suspect the amp is dead. I have reset the D2B ring through the head unit diagnostic menu. I ordered a nw amp from ebay. Ill let you guys know how it turns out.

Thanks

Be carefull. The Phone PSE and VAD voice control units are very common for locking up. Does the Bose amp have light output at the D2B connection
on the amp itself?
DR.D

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?

Dr.D,

No light output from the amp. I can see the four flash ring lock at the optic line going into the amp, I can hear the amp click four times, but then their is no light output from the amp.

Can you tell me where the voice control module is located? I am guessing it is somewhere near the phone?

Thanks for all your help!

Brian

When you perform a wake up demand, that comands the D2B master (head unit or Comand) to initiate the wake up and roll call. The roll call is the 4 flashes.
That reports to the next unit in the ring that the predecessor recieved the wake up command and is ready. Every control unit with a D2B connection
should have a single flashing red output during the wake up or roll call.
If your unit does not flash, there is a mechanical fault or a wiring issue like
the wake up line (turn on wire) is faulty.
The wake up line will have 12v at all times. When the wake up command is
issued by the head unit, that 12v is pulled down to less than 1 volt for 100ms.
A scope or really fast DVOM will be handy.
The wake up test via the head unit is for testing this electical line, not the fiber optics. That is why the lights may not flash.
Try the Diagnostic routine of Mute+1+3 for 5 seconds+.
scroll down past "versions, Tuner," and enter "diagnostics"
Go into D2B components. A list of actual vs. specified components will
come up.
The correct no fault display would be as follows.
Pos Actual Specified
000 1C8 1C8 (COMAND)
001 108 108 (AMP/BOSE)
003 0F0 190 (CHANGER)
002 190 0F0 (TELEPHONE)
004 1F8 IF8 (VOICE CONTROL)
005 0E0 0E0 (TELE-AID)

And yes, It is normal for the CD and it's successor to be reversed.
They show up that way in this screen.

If you have a actual of blank, but a specified there. that unit is
off line or faulty.

If you want to test the FOT light output of the units, just power the head
unit up. All units should flash 4 times every time you cycle the HU on and off.
Like I said, the wake-up test is for electical scope testing of the wake up circut.

Hope this helps.
Regards,
DR.D

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?

Dr. D

You are the man! I got it working. He is what happened:

I run the wake up and none of the components show up. I open the drivers footwell and check for 12 volts at the wake up line - ok.

Then, I go to the back power up the head and check for the line to go low - ok again.

Then, i short the optical circuit to only one connector and start chaecking one device at a time. What I find is that whola! the amp works alone, the changer works alone, and the phone alone. No way to test the VR. However, I also notice that when I plug the electrical in for the VR none of the other devices will wake.

So, I short only the VR out of the loop and do not plug i the electrical. Everything now works - except for the VR.

As it turns out it was the VR all along that was causing all the other units to not wake.

Thanks for all your help guys! Guess I am off to the dealer for a new VR.

Do you use it?? It is not cheap.
DR.D

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?

Dr. D,

I have not used it yet. I will call the dealer now for a price....if it is not "reasonable" I may have to wait until a used one comes up on Ebay. I took the VR totally out of the optic loop so everything else works fine. I'll post the cost when I get it.

Brian

The VR is likely repairable.

Check out http://www.programainc.com/