Pulling hair out! - Multimedia interface for comand 2.5 (S-class)

[Jeremytucker]

Hi, I have been reading this forum with interest since buying a multimedia interface for use with my '99 S430's comand 2.5 unit. MULTIMEDIA INTERFACE ADAPTER FOR MERCEDES COMAND 2.5 on eBay, also GPS Systems, Navigation GPS, In-Car Entertainment GPS, Cars, Parts Vehicles (end time 26-May-09 20:56:58 BST)

Went to install it yesterday, and i appear to either be doing something wrong, or the unit i have bought is somehow faulty. Is anyone able to clarify how this should be cabled? The unit has 6 connections;

1*DIN Style TV connection (obvious where that goes)
1*connection which mates with "C1" (previously unoccupied)
1*+12v
1*Gnd
1*"C-Bus High" connection, obviously designed to be inserted into the "C2" block connector
1*"C-Bus Low" connection, again a thin wire terminated with a metal insert for connection into C2 i assume.

I have tried the C-Bus connections into pins 8+9 which were previously empty on my C2 connector, and i have also tried them into 17-18, which had cabled going into them already, which upon removing them the AV input still didnt work, and the satnav also errored, so i put them back.

I get Audio through the interface, just no video.

Any help at this stage would be amazing and heavily appreciated!

 

[richard]

The reason you dont have speaker connections is that you have BOSE digital sound system, which means the amplifier is seperate, connected via the fibre optics

The pinouts you show are for COMAND 2.0 , and COMAND 2.5 is different. The canbus thing is for the COMAND to communicate with the 'TV tuner' without those connected it will say 'NO TV' when you press TV. From memory TV tuner and NAV go on the same canbus. But i'd probably confirm this by removing 17.18 (ignoring the fact navigation doesnt work) and put the ones you have in there and get that working, then splice together later)

You can find pinouts for comand 2.5 here: -
Mercedes COMAND Frequently Asked Questions (FAQ)

Richard

 

[Jeremytucker]

Hi, thanks for the reply Re the pinout diagram, if thats for 2.0 then i better ignore that then!

I tried 17&18, which resulted in both the satnav and the tv not working. Therefore at that point i got a little scared and put the other cables back into those slots to get the nav back!

Comand C2 connector
1 K diagnosis line
10 spare
2 To Plug E/21
11 CAN-B Shield
3 To Plug E/22
12 To Plug E/9
4 To Plug E/23
13 To Plug E/10
5 To Plug E/26
14 To Plug E/13
6 To Plug E/25 Shield
15 CAN-B L
7 D2B Wakeup
16 CAN-B H
8 spare
17 RB-CAN L (TV & E/3)
9 spare
18 RB-CAN H (TV & E/2)

The above from the link you have provided suggests that perhaps 15&16 might be good ones to try? What do you think? 17&18 look more obvious, but that doesnt explain why it didnt work when connected to those pins

I really wish the item had come with some form of install instructions, i mean how hard would it have been for them to type up a very quick guide and bundle it in with the device!

 

[ackee911]

Hello,

I have recently fitted an interface into my car. This is what I had to do:
1 connector into C1,
1 connector into the round connection (TV)
12V + & - wires
2 wires that you join to pin 17 and 18 in the C2 connector.

I had taken 17 and 18 out of the original C2 connector and my sat nav stopped working, but then I put them back, joined them up and everything works fine.

If its still not working, try different video sources (e.g. I had the same problem and tried my digital camera and dvd player-turns out I was plugging the video cable into the sound!)

Try it with the comand unit out.

Hope this helps.

EDIT: I have a instruction guide with mine, if you want I could post it to you.

 

[Jeremytucker]

Hi, really glad that ive found someone who has done the same install.

That clears up the 17&18 thing, so i need to splice them in alongside the satnav cables (like you, pulling them out caused the satnav to display a satnav malfunction message on the comand screen).

I will try it all again tomorrow, issue i have though is that even with it connected solely to 17&18 with the satnav cables out, it was still saying "No TV" on the screen when the TV button was pressed. Are you saying that yours still says that if there is no Video being fed into the unit? I expected the message to clear and see a blank AV screen or something?

Your reply is very much appreciated, as i am sure you can imagine i am so frustrated with this thing having had to work out out myself from the net! I may well have to take you up on the offer of the guide (by sending you a SAE or something) if i have no luck tomorrow

 

[ackee911]

From what you have said it seems there is a problem with your D connector-the round one.
2 questions for you:
1) What brand is the interface and has it got three buttons on the box its self (Mode, + and -)
2) Whereabouts are you?

EDIT: Just checked you have a PCCM one just like mine: See http://www.mbclub.co.uk/forums/electronics/68915-well-i-bought.html.

The instruction guide I have will be the exact same.

 

[Jeremytucker]

Wow, got it working

I am going to have words with the ebay seller, as the very basic bit of paper listing what the cables do listed the C-Bus ones the wrong way round, the low is actually high and the high low, which has cost me dearly in labour time and frustration. Bloody ebay

I very much appreciate your help. I took a lot of time to make sure that i shielded the cables well with some metallic shielding, after reports of noise. In the end i got scared about splicing into those satnav cables, so i just stripped off a fair bit of sheething off of the media box's cbus cables and wedged them into the back of the C2 17&18 connections, some electrical tape to secure the cables and it seems solid enough. Works very well at all speeds. My only slight gripe is that the audio is at a lower level than the standard functions (Radio, CDC, Tape, Telephone), so switching between these results in having to adjust it.