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Can I just buy one out of the same car or does it need to be reprogrammed? It’s a simple box with just one plug. My OBDII reader gave me a code saying BCM not communicating. I guess that is why randomly I see every warning light on the dash and I shut off the car and restart it and it’s gone. Has anyone changed one? I saw a video of a guy changing his but it was on a w215 and looked like a fuse panel. This one is under the passenger footwell and looks very simplistic. Has anyone been down this road before? Everywhere I’ve read says it’s a common occurrence.
Do you mean a SAM ? in much of the industry the name you have is that used for a customisable, network controlled, toys switching fuse box.
On Ford it was originally called a GEM (general electrical module), but they have headed off with the crowd towards your naming. But with the Germans doing everything special with much more proprietary fun, its safer to use their naming conventions. Thus on a BMW it was as simple as calling it the ZFE (spelt with a z, central chassis electronics - module). But to ensure the home mechanic can't work on it at home that has exploded in to about 15 individually named modules on current rubbish. And to be very helpful on a Mercedes it can be a Front SAM or a Rear SAM and indeed other SAMs elsewhere on complicated models.
If its a SAM no, they are coded to each car, and unless like for like part number, with the donor car also having the exact same build leaving the factory (aka same toys), you need to customise it to suit the car - and indeed they can run different firmware updates that may not be as happy as it should be with other elements of a given car. And again if its a SAM which one - both are unpleasant to change on the221
The usual culprits, are low volts and the car gets muddled - very common on a 221 as it eats 37 amps with the key on and engine off - that's before you might have external lighting on - and can flatten a brand new fully charged battery inside 20 minutes, and or the module has taken a bath (which is normal on most Mercedes), but its far less common on the 221, even though the windscreen drains are dysfunctional a week after build - due to an appalling design with leaf litter clogging them up
Thank you for that explanation but according to the OBDII reader and as it is listed on eBay they are called Body Control Module. I know all about SAMS but this isn’t a SAM. The battery is a brand new Varta MB OEM battery kept on an electronic MB charger.
OK - https://www.google.com/search?q=battery+or+body+control+module&source the trouble with the BCM acronym that is now the INDUSTRY STD, Merc already used it it for something else - as the Battery Control Module - and this is indeed an item that comes up in diagnostics for the S 221 and the E 211, yet what's shown below in the picture, the idiots at Merc are then calling the blue component in the boot.
Part 33 N82/1 the vehicle power supply control unit, just to make it all really stupid.
Thus very likely you are asking about the box of tricks above the big battery in the boot on older twin Battery cars, or the box of complexity under the bonnet making changing the battery fun for later single battery cars? If its a silly stop start car circa 2011 these die and Xentry dealer kit the way I've seen people try to fix this issue doesn't know how to help - and people fumble round and spend lots - no one seems to come back and says what really fixed it
Without glasses it looks like the blue bit is 31 rather than the blurry 33 it is, (the real 31 you don't want is to the right). I don't know if coded to the car or if it might be a very different part between low toy count and high toy count vehicles. It has some major power cables bolted to it - more like an electrical switch room than a motor car (in part where those 37 amp vanish too in my first post above) - be aware if working on a twin battery car I think taking the front off too would be pragmatic, before playing. Its not unheard of for this to pay up - usually after people put the battery on back to front - I think someone found a bit for circa $200 new inside last 12 months in a post on this forum