S
 

I can't seem to find it in the guide.

It seems to a long cycle wash does anyone know it exact purpose.

Try topping up your washer fluid. I think it stops washing the lights when its less than half full.

If its low it will tell you
 

If the washer level is low it should tell you.

Hey, i had a similar problem, bought the X5 3.0 2001 in april and did not use the Headlightwashers until december, i expected a real wash, but it was kind of weak, so i opened the hood and looked around, found Visegripclamps on the hose going to the Headlightwashers, removed them and the have worked fine ever since. It is worth a $800-$1000 credit with BMW for your unsatisfactory pre-delivery inspection you probably had to pay for (because it was not done properly or at all?). I got a credit at my dealership, i had the Visegripclamps (and photos) ready to ship back to its original owner in the factory, i still have them, because my dealership took full responsibility. Do we need the Headlightwashers at all, no not really, order something more fun with your next BMW, i know i will!

Yeah, it does say when the level is low but thats when there's approx. 10-15% fluid left ie. when you're about to run out.
I figure it stops washing the lights when below the 50%level so as to have enough fluid for the windshield.

Try it and see what happens.

Yea me to, I've the same problem but they dnt come on at all even after I pull on the stalk. Any ideas?

If you want it to wash them, you must have the headlights on and press the "S."

If you are pulling back the stalk, it will only wash the lights every fifth time -- as long as the headlights are on.

Will those rules apply to my 2000 X5?