Comand screen stopped working!

[sjmaxwell]

Came back from holiday and the battery was flat on my car (Comand 2.0 gave the usual warning). Got the car going but a week later it happened again as I hadn't given the car a good run.

Anyway, got the car going and took it for a good run and everything was ok but thought I better switch Comand off before leaving the car in the garage.

Switched Comand on the other day and although it works fine, the screen isn't working at all! So, the questions are;-

A) Is the unit completely broken and need Mercs to fix.
B) Is there a reset function for this problem; or
C) Could a competent auto electricial fix the screen (does it need a new bulb or something).

Any thoughts/help would be much appreciated as I don't fancy paying out for a new one!

 

[Flyer]

Sorry, don't know the answer, but have you cycled through the display, to check whether the display has been turned off?

It's the [ . ] button (takes a second or so between presses).

(I hesitated to post this, but sometimes the most obvious thing is overlooked )

 

[Paul Grainger]

Did you leave your nav disc in the comand when you went on holiday?

Big mistake!

300mA drain taken by comand (ignition off) when the nav disc is left in!!!!

It's a well documented issue with comand. This sort of current drain will flatten a battery quickly - it caught me out when I came back from holiday.

Paul G

 

[sjmaxwell]

Thanks Flyer and Paul.

Tried the button and did take the disc out as had the same problem last year when I went on holiday. Since then have had a new battery.

The screen worked ok after the holiday I only put that in incase it was a contributing factor to the screen failure

 

[calum]

Does anyone know if the battery drain issue - if map disc left in - also affects the current DVD-based COMAND models, e.g. in the current W211? ta...

 

[glojo]

Does anyone know if the battery drain issue - if map disc left in - also affects the current DVD-based COMAND models, e.g. in the current W211? ta...

Hi Calum
I never even realisedthat you could switch the COMAND on and off until I read this thread. Would you believe that on the 211 there is a button marked quite clearly, 'on''.

To switch the COMAND off (hopefully this will not offend 'Jimmy' as I am quoting from the COMAND instruction book. Simply turn the ignition key to position '0' or press the 'on' button. (first press switches 'on', second press will switch 'off')

So in answer to your question and the one I was about to ask

Battery drain is NOT a COMAND issue on either the 'S' or 'W' 211 because when the ignition key is extracted the COMAND is switched off.

Good luck with your new car,

Kind regards,
John

 

[Flyer]

Battery drain is NOT a COMAND issue on either the 'S' or 'W' 211 because when the ignition key is extracted the COMAND is switched off.

Ah, but that's the problem, John. COMAND, like all ICE, is wired into the ignition circuit so that it is switched off automatically with the ignition. The problem with the CD-based COMAND units (don't know about the DVD-based units) is that the unit still draws a current when there is a nav disc in, *even* with the unit switched off and the key removed.

COMAND *can* be switched on with the key removed; I do this when I leave the kids in the car, but will be switched off automatically next time the key is inserted and removed.

So, I'm afraid the question still remains; has the DVD-based COMAND a current draw with the nav disc left in?

sjmaxwell; sorry to hear that. You could try taking the unit out and removing *all* the power connectors for a period of time (half an hour?) and see if that has any effect. Bit strange for the screen to fail in those circumstances though

 

[Shude]

Ahh! Maybe this explains the battery fault I've been getting! I've had the nav disc in permanently for about a fortnight! Hmm!

 

[glojo]

So, I'm afraid the question still remains; has the DVD-based COMAND a current draw with the nav disc left in?

Hi Flyer,
I know that the DVD COMAND will definitely not work without turning the ignition on in our 211, but I have never tried pressing the 'on' button. without the ignition key inserted. When 'the boss' gets back I will give it a try. (should be back no later than 11'ish)

Do you think it possible then that there might still be 'drainage' even though the COMAND cannot be switched on?

Regards,
John

 

[Flyer]

Do you think it possible then that there might still be 'drainage' even though the COMAND cannot be switched on?

Well, you wouldn't have thought so, would you? It strikes me as a design fault that there should be a current drain if there's a nav disc in, but no drain if you take the disc out. As Peter Kay would say, "What's that all about?!"

The DVD-COMAND is manufactured by a different company (Becker?) than the old one (Blaupunkt), so hopefully this "design fault" was not duplicated.

Nick: I never take my nav disc out and haven't had this problem (original battery too; 5+ years old!*), but I don't think I've ever left it for more than a week without being used.

* Oh god! What have I done! The mighty Murphy is sure to strike me down now!

 

[glojo]

Ah, but that's the problem, John. COMAND, like all ICE, is wired into the ignition circuit so that it is switched off automatically with the ignition. The problem with the CD-based COMAND units (don't know about the DVD-based units) is that the unit still draws a current when there is a nav disc in, *even* with the unit switched off and the key removed.

COMAND *can* be switched on with the key removed; I do this when I leave the kids in the car, but will be switched off automatically next time the key is inserted and removed.

Hi Flyer,
I see your point and understand what you are saying. Fingers crossed that what you say about a change in manufacturer proves correct.

Wife knew all along about the 'on' switch. (typical) When the ignition key is removed you can indeed turn on the 211 DVD COMAND. However after a set period a visual message comes up warning you that using COMAND without the engine running may drain the battery. After twenty minutes the COMAND will turn off automatically.

This does not answer your point though about whether there is stlll a small amount of power going into the COMAND but hopefully there is no power usage. I also noticed that the courtesy lights all automatically switch off after a few minutes even with the doors remaing open

I hope I have attempted to answer Calum's query,

Regards to you all,
John

 

[Shude]

after a set period a visual message comes up warning you that using COMAND without the engine running may drain the battery. After twenty minutes the COMAND will turn off automatically.

All comand units do that, classic or new

 

[sjmaxwell]

I believe that even with the disc out there is still a drain, just less so than when the disc is in!

Comand 2.0, on CAN bus cars, can be switched 'on' when the key is removed but as with he DVD based one it will switch off after a period of time.

 

[philimayfield]

When you start up, the Command system immediately recognises your position - unless you've been parked in an underground carpark. This is because it is constantly tracking the available satellites. Other GPS sets usually need to be switched on for a few minutes to enable them to "grab" the satellites. It must be assumed that the Command is always running and thus making a drain on the battery.

 

[sjmaxwell]

Now thats odd! After prodding and poking the unit last Sunday and getting nothing, just tried the car and switched on Comand and the screen is now working!!

Whats happening?