What is happening ?

[SL63 Mark]

Sometimes when I operate the windscreen washers, the headlights wash too.

This is annoying because they cover the car in foam, and use up all the screen wash fluid.

Is this usual ? Is there a way to turn it off ? Will I have to RTFM ?

IIRC our Beemer cleans the headlights every fifth press of the washer stalk (or something) but only on a Sunday when there is a full moon, and the lights are on.

 

[Wighty]

Sometimes when I operate the windscreen washers, the headlights wash too.

This is annoying because they cover the car in foam, and use up all the screen wash fluid.

Is this usual ? Is there a way to turn it off ? Will I have to RTFM ?

IIRC our Beemer cleans the headlights every fifth press of the washer stalk (or something) but only on a Sunday when there is a full moon, and the lights are on.

My 2009 E only operates the headlight wash when the headlights are on , every 5-6 washes . Are you saying yours comes on without the headlights being on ?
Maybe the manual will yield a clue (as you suggest )

 

[Blobcat]

From 2008 ish on they removed the headlight wash button and made them come on with the screen wash every few operations. So the system is working as designed.
They then removed the whole system with LED headlights

 

[SL63 Mark]

My 2009 E only operates the headlight wash when the headlights are on , every 5-6 washes . Are you saying yours comes on without the headlights being on ?
Maybe the manual will yield a clue (as you suggest )

I think the headlights are on when the headlight washers operate. So it is working as designed.

Oh well. Probably it is part of a conspiracy and "they" are behind it.