2004 SL55, 400 miles

Is there any internal mods to the Comand head unit that will give extra features like MP3? Since the CD can read data and audio disks, it has the capability of reading an MP3 file. Ive seen internal mods for the Comand 2.0 on other websites. I have to pull my HU out of the dash to try and repair my CD drive. Figured since it has to come out I might as well ask. I am an EE with a boatload of test equipment at my disposal.

PS

What is the IF connector for?

Hi,

Not that I know off, and it definetly does not have MP3 decoding hardware, so would have to do it in firmware and there have been no firmware updates since 2002.

There are a number of connectors on the back of COMAND

Left hand from rear bottom upward
FM antenna
Diverse antenna
GPS antenna (grey HRS)

Other side, at the edge you have the D2B fibre connector, the combined ISO power/speaker connector, an 8 way small connector (called C1) (RGB video for TV and CD changer power output) and an 18 way connector (called C2) which contains CANbus, D2B wakeup, and various other signals depending on the model of COMAND

Easiest way to get USB MP3 is to add this (which pretends to be CD changer)

Comand Online Ltd :: Mercedes iPod solutions :: SL Class :: Dension Gateway LITE D2B - iPod / USB for older D2B based cars

But as Comand 2.0 does not support CD-TEXT you get no info about what is playing..

Richard

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

PS, this will help you getting COMAND out !

Removing/Installing COMAND & Audio on SL (R230)

Richard

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

Thanks. I was hoping a few jumpers or components might open up some capabilities. I ordered the test CD from my dealer so hopefully this will help in debugging the CD problem. I've been using an MP3 player with the AUX input. So your saying the "IF" connector is the diversity antenna input?

Few more questions. Do you know if the CD drive is custom or can I buy another manufacturers product and steal the CD drive from it? Does it have a manufacturer PN or a Bosch one?

I have a US unit with a SAT button. Can the video inputs be made usable at all by say adding a switch for a reverse camera? I thought I saw a document for the display that showed it had a 2 input video input mux built in. I won't know until I tear the unit apart.

If you enable the internal analog power amplifier in the unit, will the D2B output for the Bose amp be disabled? I was thinking this might be a way of adding some Tweets without adding and amp.

Years ago I reversed engineered the Bose HU used in the C5 corvette. My hardtop C5 corvette came with a cheap azz cassette HU. I wanted the Bose HU to get CD capability but I did not want to add the Bose amps or speakers. I figured out the same HU was used in other GM products but it had a preamp output for the external Bose amp. It also had different components in the tone section to alter the sound to meet Boses requirements. I did a bunch of mods to return the tone section back to "normal" and reconnect the internal power amp. The modified unit now drove four normal 4 ohm speakers direct.

Yes, that is the diverse antenna - but i'm not sure how it works.

I dont recall any markings on the cd drive, but there are on the laser (for replacement) - most likely its just dirty though

It only has 1 video input, and it is only enabled when the COMAND sees the TV tuner on the private CANbus between the comand and tv-tuner (there are multimedia adapters (see eBay) that do that.

Internal amp enabled by default. I don't know whether it actually turns off when it sees the digital BOSE amp on the D2B bus. It can also be configured for the old 'analogue' BOSE which connected to the speaker outputs so I guess that changes some output levels.

There is a whole 'table' of data that gets loaded into the COMAND by Star diagnosis which I think is equalisation data for each vehicle type. Also, there are settings for LHD/RHD and leather/cloth seats which definetly change the sound.

Let us know how you get on - theres not many people that will take on modifying COMAND ...

R

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

I've seen Comand units on ebay with an active Nav screen. I assume the unit will turn on without being connected to any of the cars electronics.

My C5 Bose stereo required the car Body Control Module, BCM be connected before it would turn on. I had to buy a used one so I could do bench testing. I am looking for a spare 2004 R230 Comand unit to do testing with. I screwed up by not buying one on ebay for $250 last week when I had the chance. A guy was selling three of them. Ebay has been blocking my attempts to contact him again.

It will hapilly turn on with just the normal ISO power connections supplied

Richard

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

(For clarity, my comment above applies to the CD based COMAND 2.0, MY2005 on SL then became NTG1, and NTG1 needs atleast the AGW connected also). MY2009 then became NTG2.5 and that will power on without anything else)

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk

Thank you for your help. Just picked up the service CD from the dealer. When I get a chance I am going to see if it loads versus the audio CDs and Blaupunkt Nav CDs I tried. Next I will try alcohol on the cleaning CD. If that fails the unit comes out. I'm still bummed I did not buy a replacement HU for $250 when I had the chance. :-(

For the Infos screen, will the number of Satellites and Speed indicators only work if the Nav CD has loaded? The Infos screen says 0 for both even while moving.

I've never checked, always had the disk in ..

R

__________________
Of course i'll take it apart.

www.mercupgrades.com
http://www.comandonline.co.uk