C Class 2004 Diesel Rapid Battery Drain

[Colin_P]

As far as I know it's 30 minutes for everything to shut down and go to sleep.

 

[television]

You cannot do it like that, a ammeter must be wired in series with the battery and the car lift min ½ hour , then read the meter

 

[sadeghMB]

Thank for the help, I have new finding, As you friends said, I connected ammeter to the battery and body in serial, setup on 10A, left the car for half an hour, the meter started with 0.95 after few seconds drop to 0.07 and after a minute drop to 0.01 constantly. I left it for half an hour to see weather it wake up again or not, but nothing changed. but when I lock the car buy remote control, it went up to 0.84. I tried to remove the fuses one by one to see whether the ampere is dropping. by removing fuse number 64 which is for (Radio, Navigation system, COMAND) the ampere dropped to 0.64 and by removing fuses 32 and 33 which are belong to (central looking and convenience locking) it dropped to 0.57 and 0.49 respectivly which is I belive a reasonable ampere leakage. now the radio doesn't work however centeral locking is still working although I removed the fuses. navigation system which I dont have and I have no Idea about COMAND. I took the fuse information from the fuse designation menu comes with the car. so sorry too long. what you guys think? Any thing I have done wrongly?

 

[television]

As the current falls away you need to change the range on the meter, you are looking for a current drain of 0.055 ma max, it is normally seat and door ECU's that cause the drain

 

[sadeghMB]

That's true, now I realized that, by removing the fuse I mentioned before,and driving the car above 10Km the back doors geting lock but the front doors not and also windows all not working, I belive the problem come from the ECU that you said, actually I realy dont know what ECU is but I think is somthing related to centralizing the doors lock, am I right? is it located in the door itself or is in somewhere else?

 

[television]

Yes the ones in the doors are known to do that

 

[sadeghMB]

Thank you television for your quick replies and Colin_P. I will update you guys as far as I get it fixed hopefully by this weekend.

 

[Alex Crow]

If you have memory seats, the ECU under the seat is top suspect.

 

[sadeghMB]

I have already checked under the seats, there are some wires attached to the seat but nothing like a device there. however the fuse that I removed caused stop draining. but I am not quite sure what else except the door ECU is in that fuse circuit. I have to find the diagram for that part.

 

[television]

Surely the ECU is in the door as it has all those switches connected to it

 

[sadeghMB]

Hi guys

My problem haven't solved, I reached to the door panel, driver side this black box was there which I believe is the ECU you were talking about. However when I removed the sockets from the box no different in Ampere usage except the power wire which caused ampere drop to 55ma which is ok. the locks and windows are working properly. do you have any idea what can problem be? by the way what ECU stand for?

 

[television]

If the current dropped to 55ma with the leads removed from the ECU (electronic control unit) then the ECU is faulty

 

[sadeghMB]

Thank you television. it can be fixed or have to change?

 

[television]

Thank you television. it can be fixed or have to change?

Its a common fault and it must be changed, breaker usually charge ½ the MB price

 

[sadeghMB]

Its a common fault and it must be changed, breaker usually charge ½ the MB price

Do you think HW and SW which are not clear in the image are important to mention when want to order a spare part?

 

[television]

The 203 820 numbers are the correct ones, the others mean nothing to us

 

[sadeghMB]

Thank you Malcolm for all your helps.

 

[television]

Always a pleasure

 

[Alex Crow]

HW = hardware version date
SW = sofware version date
Both can be much older than the part, and SW version date can be newer if updated.

Slightly unusual to have a DCM (pictured) causing this fault.

 

[television]

HW = hardware version date
SW = sofware version date
Both can be much older than the part, and SW version date can be newer if updated.

Slightly unusual to have a DCM (pictured) causing this fault.

Mine went down on my 230 Alex and pulled some 150ma when asleep, I had to program it in for the options.