ML280CDi W164 - Battery Drain
 

Hi all,
hope you'll be able to help me with my problem.
I have replaced 2 batteries during 3 months (VARTA DYNAMIC SILVER and VARTA AGM) - one day, suddenly I was not able to start the car even I've been using it evening before.
They checked all (consumption, fuses test, SAM modules, alternator) but everything looks like it's OK - any idea ? I don't want to be stucked somewhere sometime.
Thank you very very much!

Not right! Try a different auto electrician. Not a dealer.

thanks iankayem - this is not dealer, it's my electrician - 10+years of experience with MB

I don't like to disagree with another poster, but I would take your car to a dealer. The electronics in the ML are unbelievably complex and weird gremlins can strike at any time. Diagnosing them without the proper computer can be almost impossible. My ML's battery recently went flat overnight for no apparent reason. It turned out to be a glitch of some sort in the COMAND unit. The whole unit was replaced under warranty. I had the same thing happen about 18 months ago and it turned out to be a bad battery, also replaced under warranty. Search any of these forums and you'll find dozens of posts about strange electrical faults that appear and then seem to cure themselves, only to reappear months later.

thank you also for your reply; we've been trying all I found here on the forum ... and also in contact with original Mercedes Benz service here in Slovakia (with cooperation to Germany technics) - but apparently haven't found reason for now....I'll try to upgrade command today with v.12 navigation ....we never know...maybe it helps

I appreciate disagreement, especially when it is backed up with sound advice. My main concern is the second opinion by a qualified person.

hi guys, so they tried to disconnect power seats (both driver and passenger) but the consumption after locking car was high (0,3ampers)...today they'll try to disconnect fuses (one after another) to find out if the consumption dropps.....any other idea?

Thats a logical procedure.

Hi guys - we found out that the battery is drained by radio circuit - when I disconnect radio (china alternative of command www.klarheim.de ) the consumption drop .... any idea how to solve this?

First is this radio still under warranty? Even if it is Chinese, you should not expect this if it is in a saleable condition. :nix:

If the Klarheim folks don't accept a claim, throw it in the bin and search the wreckers or EBay for a genuine replacement.

thank you for reply - yes , it's under waranty but I don't wanna wait 30days for just reaction to claim....would most probably try to sell it - any interest to buy at 500EUR?

What 500EUR for the radio that's crook, or for the ML without a radio? :nix:

You can survive for a month without a radio, whilst you get the radio repaired or replaced. Then enjoy your motoring.

I know I am replying to an old post. I bought a second hand 06 ML500 and faced the same problem with.
The problem is that on the original Comand NTG2.0 the ISO harness the B+ (Direct Battery Connection) and ACC (Power via ignition switch) are always on. The Unit will be continuously on and will not go to Standby as ACC is not switched off.
You have to source an ACC power source and modify the ISO harness adapter wiring of the aftermarket accordingly.

Thank you-to better understand could you share some diagram/picture how to connect?

The attached picture is an example of an Aftermarket Navigation Unit. The wiring to the ISO harness might vary from one manufacturer to others.
Further the CANBus interface could also be the cause for the ACC be permanently available.

You need to contact the nearest MB dealer and ASK if their are MB service bulletins available regarding this issue.

Are trying to sell a faulty cheap CHINESE radio now? WOW...:confused: