SLS + headlight level sensor

[Ryoken]

now I don't think its a daft Q , but here we go , ill try to explain as good as i can.
i do know i have self level inact error on my car at the moment,
the other week i noticed that my rear right corner is lower than my rear left , maybe 2 inch, when the car is off and its been parked up . when i fire the car up the airbag of the right lift it up so its level ,
ive had it in the other day for some work doing on it , and the indy says he cant see anything wrong with the airbags.
if i have the ignition on , and jack up the rear left of the car it should i think force the other side up to level the car, and then i can check for leaks
also correct me if im wrong but , number 19 on this , does both headlight AND suspension level??
RealOEM.com * BMW E53 X5 4.4i LEVELL.DEVICE, AIR SPRING AND CTRL UNIT

reason why i ask this is i read my codes other day and i keep getting this
LCM -> Shadow-memory:
57/02 - Level control system
im wondering if that sensor could be going bad and its causeing both the suspension and the headlight problems??
plus the sensor at the rear of the car that i beleive works the the sls, if you remove the arm from the chassis and physically move that it should "tell the computer" the level is off?. it could be a way to determine if its a sensor fault or a bag fault ,

not really stupid questions really