2004 E320 Wagon Command system problem. - PeachParts Mercedes-Benz Forum

desert · #1 10-19-2011, 11:29 AM

My inquirey about my radio cutting off periodically was relagated over to the "radio" forum where it has received no response so let me ask a couple of other more general questions.
1. Is the Command system powered by the main battery or the aux battery?
2. One possible solution to my problem which I fround on another MB forum was to disconnect the main battery for a few minutes then reconnect. The guy said this re-set the system and all was ok after that. Is this recommended as a possible solution or does disconnecting the battery somehow then require re-setting full car software etc?
Thanks, Desert

lkchris · #2 10-19-2011, 11:47 AM

Your owners manual covers what needs to be reset following battery disconnection.

EVERYTHING is powered by the main battery ... until it fails.

FWIW, COMAND (not Command) units are available through Mercedes' rebuilt parts program.

ILUVMILS · #3 10-19-2011, 12:19 PM

Quote:

Originally Posted by desert

....One possible solution to my problem which I fround on another MB forum was to disconnect the main battery for a few minutes then reconnect....

This is what's known as a "hard re-set". It's a great way to restore functionality to all kinds of mis-behaving automotive electronics. I use this technique regularly to bring dead ECU's back to life, in fact, I did this about an hour ago to revive a W204 instrument cluster. The re-set is a diagnostic tool though, not a fix.

The COMAND system on your car is the first version COMAND for the W211. There are plenty of known issues, many of which can be fixed by installing updated software. Most likely will require a trip to the dealer. Having the system scanned for fault codes should be your first step.

desert · #4 10-19-2011, 02:16 PM

Thanks very much for the good info, today the radio worked fine but the next time it goes out I'll try the " hard re-set" proceedure and if that doesen't solve the problem it will be a visit to our local MB dealer for software up date. Thanks again, Desert
PS Question: If the main battery powers "everything" why does the car have an AUX battery?

ILUVMILS · #5 10-19-2011, 05:10 PM

Quote:

Originally Posted by desert

....Question: If the main battery powers "everything" why does the car have an AUX battery?

Backup power for the SBC brake system.

desert · #6 10-19-2011, 06:54 PM

Thanks for the response re:AUX battery..... Now, one more question please. Are the metric bolts that attach brackets etc to the 110 engine different than "standard" metric bolts? The reason I ask is I had to replace the AC tension pulley on my 85 280SL Euro (with after market AC) and the bolt that attaches the bracket to the block was ground smooth on one side from the after market pulley. I went to our local ACE that has a good selection of metric bolts but I couldn't find one that had the same threads and couldn't even find a nut that would fit my bolt which leads me to beleive that the MB bolt may not be standard ??