2009 x5 48i - issue started with key fob not working.  Simple fix, fuse 127.  That started fixing it for roughly a week, but not it only lasts seconds.  The radio randomly works.  The airbag warning is on.  Today the gf texted me that the awd gave a warning as well as the backup camera stopped working.  Last weekend, we found the battery was dying (down to 100 CCA).  Swapped it out, and everything worked for 2 days, except the airbag warning which will likely need to be reset.  Does anyone have an idea if all of these could be linked to something?  All I can think of is one of the computers may be going bad.  Thanks!!