Is Comand navigation likely to be the root cause of the battery drain in a 2003 W211?

[bigdieselfan]

After suffering from a flat battery a couple of times I replaced the battery as it looked like I was still on the original battery. All was well for a few days, then I had another flat battery. I took the car to MB and after two hours of disconnecting things they identified the navigation unit causing the drain. They disconnected the navigation unit (DVD) in the boot and did some electronic meddling so that the Comand system didn’t think it had navigation anymore (this was done to get the radio working again)

The car starts fine now I don't get any more [FONT=&quot]“Convenience function unavailable” messages [/FONT]but I’m missing the navigation and traffic info. The firmware of the navigation and Comand itself were upgraded to the latest firmware versions a year or two before the drain problem (2010 maps and the service update W 211 589 13 22 00 respectively).
I’m wondering what options I’ve got – is there a fuse for the navigation unit that I could take out if I leave the car for more than a couple of days? MB said there isn’t one. Is it possible that the navigation unit can have a part replaced to stop the drain? An extra switch maybe or something else?

Thanks in advance for your ideas.

 

[Marku]

Didn't they say how it was causing the drain? COMAND switches itself off pretty quickly if the engine is not running so perhaps that is not working properly. I would have thought you would have even more problems in connecting/disconnecting as the system would not recognise it as it probably wouldn't if you re-connected it now. Try COMAND online they seem to know all the mysteries of it.

 

[npuk]

Yes I have heard of the navigation causing battery drain. From what you have said they have disconnected the nav processor in the boot as that is the item causing the drain.

You could possibly get yours repaired or alternatively replace the nav processor, units available on ebay. Also forum member S.Speed has just one had removed from his 2007 E Class as he has upgraded to Comand NTG2.5 so contact him for a price for his.

If you want to find out about a repair contact comand.co.uk or type in ebay 'comand repair' there are a few companies that do repairs.

You will need STAR coding to get the nav turned back on. Comand.co.uk are based in Lightwater, Surrey and they can do it for you.

 

[bigdieselfan]

Thanks very much for such a speed reply Gents. I'll try Comand Online for likely repair costs and also fish around to see the price of a second hand unit.

Marku: MB at Heathrow were helpful, but in an unhelpful way - just saying that they could only replace the unit for silly money. Nothing about repairing or the cause.

Npuk: Yes, your synopsis of what the dealer did sounds spot-on - and more succinct than my explanation! Thanks for the advice and heads up that S.Speed might have a unit up for sale.