Cartronics

Similar posts have been made before for the C Class radios, changing the cassette to Aux Input. However, I was not able to find anything on the COMAND 2.5 that is used in cars such as the 2000 - 2002 S Class (W220). This removes the need for a cassette adapter, and dramatically improves the sound quality by bypassing the head and head preamp electronics and going directly into the output stage of the COMAND. The only tools you need are:

1. Torx Screwdriver
2. Soldering Iron
3. Razor blade
4. (Optional) Drill for professional wire install

Supplies needed are:
1. Solder
2. Wire with appropriate jacks (in this case female RCA left and right audio)
3. (optional) grommet for professional install
4. 1 ZIP Tie

STEP 1. Remove cover of radio and take out four screws holding cassette mechanism in place.
STEP 2. Remove red plug from back of cassette mech
STEP 3. Remove cassette mech and remove four screws holding bottom frame to mechanism. This will expose a belt and the back circuit board.
STEP 4. Rotate gears of small motor to lower the cassette mechanism into the play position.
STEP 5. Drill hole in back of main radio body, directly behind mechanism (tip, turn radio upside down while drilling so debris does not get into radio and just falls on workbench)
STEP 6. Install Grommet (picture 1)
STEP 7. Insert wire (connectors) through grommet. Strip 1" of outer insulator and 1/16" of inner insulator.
STEP 8. Wrap ZIP tie around wire INSIDE the radio and pull tight. This will prevent the wire from being pulled loose when in use or installing. (picture 2)
STEP 9. Cut traces on circuit board as shown. (picture 3)
STEP 10. Unplug motor plug on end of circuit board. (picture 4)
STEP 11. Solder wire to GROUND, LEFT and RIGHT points on board as shown
STEP 12. Reassemble (picture 5)

When you want to listen to AUX input from MP3, or even watch a movie on the screen with the sound (using our Video In Motion kit), select the TAPE function and enjoy high quality audio!

Total time on this install is about 30 minutes once the radio is out.

Arnee

Good stuff.

Question: Does it have to be L/R RCA plugs?

Will 3.5mm jacks work fine? Impedance is the same?

Thanks.

tusabes

If we send our unit to you can you perform the mod and charged us the half hour labor?

Cartronics

In this particular install we installed L/R RCA female jacks. However, any attachment point could be used.

We have a minimum one hour labor like most shops do. You would need to call us directly to arrange for us to do it at 678-528-3443.
Also, a local shop could follow our instructions if they are electronics technicians.

classyS

whoa very nice diy mod, how do u remove the radio?? someone find a step by step instruction and i will give it a try, worst could happen is no tape deck??

classyS

damn i just realized i have a 2001 which doesnt have command 2.5

rnitto

Great stuff!

What do you mean by "CUT TRACES" in the 3rd pic?

Cartronics

using a razor blade or other tool, you CUT through the foil "trace" or "circuit line" as shown in the picture.

classyS

soldering 101.

its been a decade since my electronics class, if i remember correctly..

1. apply minimal amount of solder to wire. (or apply on solder gun tip)
2. using solder gun, heat wire just above the solder previously melted on tip of wire. (or join gun tip with wire to circuit board pin/lead)
3. join melted solder on circuit board lead carefully.

correct me if im wrong guys, thanks in advance!!

Cartronics

you can move on to Soldering 102 now - you have graduated from 101

classyS

lol thanks Cartronics, im doing the mod as we speak but im just preparing and verifying a few things,

so i went with 3.5mm female jack, in the picture shown below;

red wire is RIGHT / black wire is LEFT / and ground is well.. ground (duh.)

classyS

JUST finished this mod. lol took me 2.5 hours due to my son crying/feeding time but should take 30-45 mins easily.

1st time uninstalling COMAND 2.5 wasnt hard at all, most connectors are straight forward..
soldering the left/right/ground were the hardest of all, its been 10 years since ive soldered anything.

so far ive tested laptop, generic mp3 player, ipod, ipad and all seems to work.
having disconnected the motor inside tape mechanism prevents from switching out of "PLAY" position - very cool mod.

will upload pics later, keep posted!!!

Cartronics

AWESOME!!! - Glad I could help

classyS

just want to clarify on one of the steps..

when moving the small motor, should we move the notch in the "R. PLAY" or "F.PLAY" position?

all was working but sometimes the tape player opens up, then closes only upon power up of comand lol

i figured by doing this mod, worst could happen is no tape player and also gives a reason to upgrade comand 2.0 2003 model =)

beachcomber

Hi, You must have been here before me. I'm looking for help in removing the radio cassette. How do I do that? I have removed the screws behind the ashtray. The walnut surround seems to be held at the top. I am told that I may find some screws to release the radio under the horizontal walnut strip that runs along the dash. I have been popping this strip up carefully but it stops coming off at the glovebox. Anyone know what next??

gurraj_singh

Am I right in assuming that this AUX conversion will NOT work on a 2001 S320L CDI ?

Komawi

Today I did this modification. After closing up and installing it back into the car, the COMAND works properly, but after pressing the TAPE button, it displays the notification "No cassette" and does not relay the sound I send into it. What did I miss in the modification Maybe one of my trace cuts wasn't deep enough? I detached the motor cable as described, also the cassette deck is lowered into 'play' position (rotated the gears as far as possible) and soldered the wires on the specified places.

By the way; my avatar is out of date, I drive a S320L (W220) now

@beachcomber: I struggled with the problem you mentioned as well. Behind the ashtray there are 2 screws. Remove these first. You can then remove the ashtray and pull the bottom side of the wood towards you. The wood is also fixed at the top side. However, on the top side there are two pressure clips, not screws, one top left, the other top right. Just make sure you get your fingers or something else under the wood as high as possible and pull it straight towards you.

Capnahab

Reviving this somewhat aged thread.. I've just tried this, but to no avail.

I'm getting the message 'no tape'

I've got the unit plugged in with its top off, and I'm manually inching the tape motor along enough to get rid of the No Tape message but there isn't any sweet spot that does it. Tape lowered all the way in and out doesn't get rid of No Tape.

Capnahab

OK - I inserted a tape and now all is working well - no music coming from the tape itself (I cut the traces as above) and my iPod aux feeds the Left & Right

I'll try the reccomendations above - remove the tape now anddisconnect the motor and lower the cage to the play position just in case it needed to see a physical tape to make this work. But I would say that leaving a tape in is not a big problem, the motor is virtually silent in mine. I suppose I could lower a tape in the module then disconnect the motor actually, that'd do it..

HurtfulGuide8

worked out really good on my Comand 2.5, thank you for sharing your knowledge

Kev100

Sorry to drag up an old thread, just done the mod and all is working fine, sound is good, except I have to have a tape playing in the tape player, and the motor plug plugged in to get any sound, I would rather not have this as sometimes when the sound is low I can hear the tape going round, its not such a big problem, but if anybody has any suggestions to stop this I would appreciate it,

Thanks

Kev

Capnahab

I couldn't get around it I'm afraid but I couldn't really hear the tape spinning either, worth running a cleaning tape through?

Kev100

I have done this mod so that I can install a nexus 7 in place of the 2.5 command system (think the command system looks ugly and dated), so as was suggested to me in my other thread about the nexus install I will try push the command unit back as far as it will go, and mount the nexus in front of it, then will be putting a new double din fascia in place of the original.

So hopefully if the command system is pushed back and behind the nexus it should muffle the sound of the tape player to the point that its not really an issue.

victorczx3

I have done this mod but have issues, when it works it sounds great, but when you change the track on phone it make a nasty static sound ( like dropping a mic on floor noise ) every time . then after a a few minutes phone will not recognize aux input and stop playing on car only phone speakers. ( but tape continues to turn with no sound it says " playing side A" )
I left the tape running and its the only way it works ( i don't mind the tape ) as long as it works.
In order to play again I have to unplug harness in the back for it to reset.
what have i done wrong or am i missing something???
please help ( I Hate radio here in DC and My cd changer is stuck )

thanks in advanced

Victor

Kev100

I had a similar problem with my S3 and it was the headphone socket in the phone that was making a bad connection, so you could try another device to eliminate this, also try another cable from the phone to the head unit, I have had problems with those in the past, apart from that not sure what else to tell you.

I too apart the tape and removed the internal spools so that it didnt make the sound of the spools going round, but still recognises the tape so the mod will work.