dreaded self leveling inactive showed up..had the accumulator error code, vehicle would not move off of the middle setting when high level pushed...green light flickered as though it was instructed to do by the ehc2 control module. through trial, error and a few visits to two independent shops, searching through on line articles for self education, arrived at buying a used eBay unit from a salvage for $225, whole black pot, swapped it out, took it to have the vehicle re-set at the BMW Dealer who set it and said all was well...drove away and within two blocks, the dreaded red lights came back..took it back and they re-set it again, this time maybe doing additional height calibrations...not sure but since then, all is well...
Also did the air compressor piston change from the Andy guy on eBay. $41 kit, real easy to change, so now I have the original pump unit as a back up.. moral of the story...if it flickers but doesn't move, if you get the light and code is accumulator ...it is most likely a worn air compressor piston ring...the ring is Teflon, likely to keep the noise down and it obviously wears fast..so, get it fixed if it has a leak because the system will call for the compressor..love this beast..