First thing to understand is what the LCM is. The LCM is a module that controls all exterior lighting and it also is where the prority warnings for the check control system. BMW used to have 2 separate modules...the LM (light module) and the CCM (check control module)...but the function of these two components where combined into one module.
Secondly, the LCM also contains redundant data with the IKE...so installing a used one usually creates issues unless you have aftermarket software/hardware to get around this.. BMW software/hardware can NOT install or code used LCM or IKE modules because it would be easy to slip into odometer tamporing...so BMW DIS/GT-1/MoDiC is designed not to have this capability to program used modules.
So, the info you've find is probably misleading you if you weren't aware of the above. If your suspension is actually notactive, then diagnostic equipment could tell youwhat or where the issue lies. The brake bulb may be a corrosion problem. Have you checked the tail light assembly for pitting or burn marks where the contacts on the bulb holder mets the reartail light assembly? Or it could be an internal circuit boad issue withyour LCM.