Voice Control/Command Module Location Help
The dealer and other threads say it's in the left side of the trunk. I removed the left trunk panel and cannot find it. Two pics of a left-side trunk is attached, mine is exactly the same. I removed those "modules", including the one hidden behind the black spring (in pic 4406), but none of them had the same part# and their labels indicated they were not voice control/command modules.
Anyone know where the Voice Control/Command Module is located? Is it likely I need to replace this module to get my voice comman button to work? Can a DIY'er do it without a fancy Star analyzer/programmer? There's no returns on electrical parts, so I'm hoping there's some certainty this part#221-870-38-87 will fix it?
I do already have the updated Command software that allows birds-eye view and to play DVDs. The voice command and phone calls worked fine until it broke a couple months ago.
Much thanks,
Drew

Did you check this part in the red circle?
I don't think it's the microphone because when I press the Voice Command Button I see no Command screen response. If it were only the microphone I would think the Command screen menu would still change, awaiting for voice input. Still, that is why I have some concern. Others have mentioned their MP3 or CD audio songs cut out or menus jumping about, which isn't happening to my system.
When I take the car in for an A service I'll ask for a quote to fix the VC button and pay the Star diagnosis fee, if they insist. If they point to the VCM then I'll take the risk and buy it. Hopefully a simple swap is all I need but if anyone knows if there's more to it please let me know. The dealer quoted a guy $2600 for what appeared to be a VCM swap, and they told the guy they weren't 100% sure it'd fix the issue.
Much thanks again!
After reading some of the threads, I figured I could just replace it myself. I found a part on ebay (221 870 38 87) and it arrived today. I pulled out the old one (221 870 20 92) and replaced with the new. After buttoning up the whole car, nothing changed. I did disconnect the battery and reconnect after the install.
Any ideas what to do next? Am in for the whole 2 grand?
Initially they said they got it to work and had me come in to pick it up. However I got home and it didn't work. They messed up on the testing part. Took the 07 S550 car back and they tried again but couldn't get it to work, but verified a new VCM did work. They still had some issues getting the new VCM to work. They did spend a decent amount of effort and made me come back a couple times so charged me at wholesale cost for the new VCM part ($1100) plus one hour. They even fixed it after my iPhone wouldn't synch up contacts. Total out the door maybe about$ 1300 and my multiple trips. I think they learned some things and I was reminded sometimes DIY doesn't work so well. It appears for a 07 s550 it may be a complicated fix. Can't remember exactly but I think they originally quoted about $1800, so try to get a discount or look for a 10-15% off deal.
Unfortunately VCM is too nice to have so you may need to budget for it.
Last edited by wwwdrew; Nov 9, 2013 at 11:46 AM.
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Btw, I didn't lose all audio. Stereo still worked and I could hear people on a Bluetooth call. But my S550 completely ignored anything I told it.
Last edited by wwwdrew; Nov 9, 2013 at 11:48 AM.
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He said that they had some special diagnostics that must go through the factory back in Germany.
I will provide more details as I trouble shoot my problem. I get no response when tapping the column stalk.




