Help!!! Gremilins in my Command Unit?
Thread Starter
Newbie
Joined: Jun 2010
Posts: 2
Likes: 0
2003 S430
Help!!! Gremilins in my Command Unit?
I have hit a brick-wall! 
My wife's 2009 ML320BlueTec has a Command unit that appears to be caught in a loop. When I push the power button on for the radio, the Mercedes logo comes on the display and the radio starts to play on whatever station it was playing last. That lasts for about a couple of minutes with absolutely no change and then it turns itself off and will restart by itself and do the same thing: Mercedes logo on the display screen and radio playing sound. While it is in that state (radio playing and the screen displaying Mercedes logo) I have tried pushing all buttons there and on steering wheel and nothing happens. The ONLY button that works is the power button. I can turn it on and this will happen continuously in a loop or I can turn it off and screen and radio go off. Here is another strange thing: while the whole thing is turned off but the engine is running or the ignition switch is on, I feel the same thing is happening internally because I hear what sounds like a hard disk drive turning off every couple of minutes. The best way I can describe the sound is when you turn off your laptop computer, there is a faint click that you hear when your laptop's hard disk drive shuts off. If that makes any sense, that is what I hear if the car is running even when the radio unit is turned off.
Took it to an independent MB shop and he told me that I need a new command unit because his diagnostic tool cannot even connect to the command unit to diagnose, do software update, or do anything else? He has the proper machine/tool that he uses to do software updates and diagnostics but it is unable to make a connection to diagnose mine. Just to make it clear, this is not a connector compatibility issue but a communication connection issue. It plugs in fine but it cannot "talk" to my command unit. Has anyone had this issue or can anyone shed some light on what it could be? I have read elsewhere that issues with the SAM unit may cause that and some have even written that it could be a software update. I have learned a lot and solved a few problems from the great people here on MBWorld and thought I may get a lead to head in the right direction. This ML has only 58K miles and is in pretty decent shape otherwise. So, radio is stuck on one station (can't even see what station because the screen is stuck on Mercedes logo) NAV does not come on, back-up camera does not display, no bluetooth connection...absolutely nothing but radio sound for two minutes at a time with a short interruption while the system restarts and does the same thing non-stop. I just don't want to gamble putting another command unit which is $$$$$ and that not being able to address the issue.
Thank you, in advance, for your help and ideas.
My wife's 2009 ML320BlueTec has a Command unit that appears to be caught in a loop. When I push the power button on for the radio, the Mercedes logo comes on the display and the radio starts to play on whatever station it was playing last. That lasts for about a couple of minutes with absolutely no change and then it turns itself off and will restart by itself and do the same thing: Mercedes logo on the display screen and radio playing sound. While it is in that state (radio playing and the screen displaying Mercedes logo) I have tried pushing all buttons there and on steering wheel and nothing happens. The ONLY button that works is the power button. I can turn it on and this will happen continuously in a loop or I can turn it off and screen and radio go off. Here is another strange thing: while the whole thing is turned off but the engine is running or the ignition switch is on, I feel the same thing is happening internally because I hear what sounds like a hard disk drive turning off every couple of minutes. The best way I can describe the sound is when you turn off your laptop computer, there is a faint click that you hear when your laptop's hard disk drive shuts off. If that makes any sense, that is what I hear if the car is running even when the radio unit is turned off.
Took it to an independent MB shop and he told me that I need a new command unit because his diagnostic tool cannot even connect to the command unit to diagnose, do software update, or do anything else? He has the proper machine/tool that he uses to do software updates and diagnostics but it is unable to make a connection to diagnose mine. Just to make it clear, this is not a connector compatibility issue but a communication connection issue. It plugs in fine but it cannot "talk" to my command unit. Has anyone had this issue or can anyone shed some light on what it could be? I have read elsewhere that issues with the SAM unit may cause that and some have even written that it could be a software update. I have learned a lot and solved a few problems from the great people here on MBWorld and thought I may get a lead to head in the right direction. This ML has only 58K miles and is in pretty decent shape otherwise. So, radio is stuck on one station (can't even see what station because the screen is stuck on Mercedes logo) NAV does not come on, back-up camera does not display, no bluetooth connection...absolutely nothing but radio sound for two minutes at a time with a short interruption while the system restarts and does the same thing non-stop. I just don't want to gamble putting another command unit which is $$$$$ and that not being able to address the issue.
Thank you, in advance, for your help and ideas.
Junior Member
Joined: Jul 2012
Posts: 37
Likes: 0
2008 mercedes c350
I have hit a brick-wall!
My wife's 2009 ML320BlueTec has a Command unit that appears to be caught in a loop. When I push the power button on for the radio, the Mercedes logo comes on the display and the radio starts to play on whatever station it was playing last. That lasts for about a couple of minutes with absolutely no change and then it turns itself off and will restart by itself and do the same thing: Mercedes logo on the display screen and radio playing sound. While it is in that state (radio playing and the screen displaying Mercedes logo) I have tried pushing all buttons there and on steering wheel and nothing happens. The ONLY button that works is the power button. I can turn it on and this will happen continuously in a loop or I can turn it off and screen and radio go off. Here is another strange thing: while the whole thing is turned off but the engine is running or the ignition switch is on, I feel the same thing is happening internally because I hear what sounds like a hard disk drive turning off every couple of minutes. The best way I can describe the sound is when you turn off your laptop computer, there is a faint click that you hear when your laptop's hard disk drive shuts off. If that makes any sense, that is what I hear if the car is running even when the radio unit is turned off.
Took it to an independent MB shop and he told me that I need a new command unit because his diagnostic tool cannot even connect to the command unit to diagnose, do software update, or do anything else? He has the proper machine/tool that he uses to do software updates and diagnostics but it is unable to make a connection to diagnose mine. Just to make it clear, this is not a connector compatibility issue but a communication connection issue. It plugs in fine but it cannot "talk" to my command unit. Has anyone had this issue or can anyone shed some light on what it could be? I have read elsewhere that issues with the SAM unit may cause that and some have even written that it could be a software update. I have learned a lot and solved a few problems from the great people here on MBWorld and thought I may get a lead to head in the right direction. This ML has only 58K miles and is in pretty decent shape otherwise. So, radio is stuck on one station (can't even see what station because the screen is stuck on Mercedes logo) NAV does not come on, back-up camera does not display, no bluetooth connection...absolutely nothing but radio sound for two minutes at a time with a short interruption while the system restarts and does the same thing non-stop. I just don't want to gamble putting another command unit which is $$$$$ and that not being able to address the issue.
Thank you, in advance, for your help and ideas.
My wife's 2009 ML320BlueTec has a Command unit that appears to be caught in a loop. When I push the power button on for the radio, the Mercedes logo comes on the display and the radio starts to play on whatever station it was playing last. That lasts for about a couple of minutes with absolutely no change and then it turns itself off and will restart by itself and do the same thing: Mercedes logo on the display screen and radio playing sound. While it is in that state (radio playing and the screen displaying Mercedes logo) I have tried pushing all buttons there and on steering wheel and nothing happens. The ONLY button that works is the power button. I can turn it on and this will happen continuously in a loop or I can turn it off and screen and radio go off. Here is another strange thing: while the whole thing is turned off but the engine is running or the ignition switch is on, I feel the same thing is happening internally because I hear what sounds like a hard disk drive turning off every couple of minutes. The best way I can describe the sound is when you turn off your laptop computer, there is a faint click that you hear when your laptop's hard disk drive shuts off. If that makes any sense, that is what I hear if the car is running even when the radio unit is turned off.
Took it to an independent MB shop and he told me that I need a new command unit because his diagnostic tool cannot even connect to the command unit to diagnose, do software update, or do anything else? He has the proper machine/tool that he uses to do software updates and diagnostics but it is unable to make a connection to diagnose mine. Just to make it clear, this is not a connector compatibility issue but a communication connection issue. It plugs in fine but it cannot "talk" to my command unit. Has anyone had this issue or can anyone shed some light on what it could be? I have read elsewhere that issues with the SAM unit may cause that and some have even written that it could be a software update. I have learned a lot and solved a few problems from the great people here on MBWorld and thought I may get a lead to head in the right direction. This ML has only 58K miles and is in pretty decent shape otherwise. So, radio is stuck on one station (can't even see what station because the screen is stuck on Mercedes logo) NAV does not come on, back-up camera does not display, no bluetooth connection...absolutely nothing but radio sound for two minutes at a time with a short interruption while the system restarts and does the same thing non-stop. I just don't want to gamble putting another command unit which is $$$$$ and that not being able to address the issue.
Thank you, in advance, for your help and ideas.
Thread Starter
Newbie
Joined: Jun 2010
Posts: 2
Likes: 0
2003 S430
The silver lining on this cloud is that there are vendors who will rebuild your defective units or sell you a rebuilt unit for much less than what a new one will cost you. Even the Mercedes dealers stock rebuilt units - mine had 4 of them in stock. That tells me that these units do fail regularly. All said and done, I ended up spending about $600 by pulling the unit out and shipping it to a shop in the San Diego, CA, area and putting it back in once I got it back and it is still working now. I have seen others who offer to rebuild them for as little as $250 but I cannot say how good or bad they are.
I was hoping that I would have contact information for the shop I used but I will have to do some digging through all the receipts in the folder for that car.
I hope this helps. Good luck!
Junior Member
Joined: Dec 2013
Posts: 44
Likes: 1
From: Monterey, CA
2006 Mercedes ML 350
Junior Member
Joined: Aug 2014
Posts: 62
Likes: 0
From: St. Louis
ML350 Blutec
I have not had the problem but have read about it in this forum. Do a google search and you will find it, one of the guys noted unhooking all the plugs letting it sit for a few minutes and hooking them all back up and it worked.
I have an ML350 with the Command unit and have been trying to learn as much as possible about these SUVs.
I have an ML350 with the Command unit and have been trying to learn as much as possible about these SUVs.
