Sntkeel

I have found out where my draw was coming from thru the fuse pull method and determined it was fuse 61 Telephone sys/Emergency call, voice control. When I pull fuse there is no longer a draw and battery maintains charge. My problem lies in that by pulling this fuse, I then get a warning on my display SRS system and take to workshop. I do not have the wiring schematic, and dont know if I could understand it if I did. If I put fuse back in the warning on my display goes away, but I am left with the parasitic draw again. Does anyone have any ideas on where I might go to next to find a solution. I think that maybe this system is keeping the car awake thus the drain. When the fuse is in its current draw is .35 amps and when it is pulled it drops to the acceptable level of .050. Any help, any ideas, any experiences shared would be greatly appreciated. My vehicle is 2003 S500.

CaliBenzDriver

Many modules can stay awake and drain your battery namely "Sleepless SAMS": they manage the power wake up activities.

The module you are designating is the "mbrace" module that's usually located forward of the trunk area.
Basically it keeps trying to register on a 3G cellular network that has now been phased out.

I recall seeing a MBUSA TSB regarding a firmware update published to fix that known bug. The update is 100% free... but not the preliminary troubleshooting

It's a good habit to float these car batteries when convenient to prevent wasting them for XYZ reasons.