i have on my 530d (2004) non zeion headlights.

when i turn on my car at night, i see the beam rise up (to normal level), almost from pointing at the ground to level (if that makes sence)
why do they go down when the cars turned off? and whats this for?
i know the lights can be adjusted for height/load carried, but this happens every time the car is started and i turn lights on ?
i find it bazare.

 

this happens to my xenon lights too.never understood why.

They start normal level, go down, then go up.Sometimes they dont.no clue why.would like to know too.

 

The law in many countries requests that xenon lights must be automatically leveling. At least here in Finland.
There is a sensor in your car that measures the level of chassis and then levels the lights.

And maybe David has this feature too altough he doesn't have xenons...?

 

First paragraph explains...

Self-Leveling Headlights


They most likely go through a "startup" procedure and system check. If the car does not go to sleep and is restarted again, it may not go through the same startup sequence.

HTH

 

i have xenon's on my 535d but that does not go up and down like the 530d with "ordinary" headlights.

 

Hi

The car does that to reset the aut. leveling ( cars with Xenon ), on "non" xenon cars it does it to control the function of the littel motor that levels the headlight when the botten ( scroll wheel at the light switch ) herefor is activated .

The car dosen't make this "control" if the car just have been turned of for a short time ( not gone into "sleep" mode ).

Hope this clarifyes it a bit for you , why your car seems to live its "one" life , regarding the headlights

PS: Only cars with Xenon have the auto leveling ( one sensor on the front axel and one on the rearaxel ) , all cars with halogen is manual activated

 

i understand that benand, but why does it "reset" itself? whats the point?
why not stay at the correct lever untill altered? it seems to be working for no aparent reason?

 

@drDave: I think it's probably got to do with the fact that the sensors and/or actuators that set and control the level are electronic rather than mechanical. Mechanical actuators will tend to stay in whatever position they were last left in, but electronic ones may not necessarily behave that way. Therefore, they need to re-align/do an alignment self-check when initiated after the car has been asleep.

 

Hi

I been told it's be course it is a Lin-Bus signal that have to reset its values between the sensors and the leveling electrionic/motors in the headligth , at the same time it is a contrlo that the 2 leveling motors ( one in each headlight ) allways is in the same position ( up/down ) , regarding the signal from the sensors .

If you try to "set" the headlights adjustment manualy to much , you will risc a faliur message , be coruse the leveling electronics "work aerea" now is extended out af reach.

 

thanks, that ties up with what MacSid said also.