ChuckinTucson

I have a 2012 S63. In the last week or so, my headlights have been turning on even in the middle of the day in bright sunlight. Doesn't happened every time. It only does it when the car is started. They don't come on while driving unless I go into a tunnel, and then shut off as soon as I exit the tunnel. Occasionally the lights will stay on until I restart the car. Other times they'll go off on their own while I'm driving. I'm thinking it might be that the sensor is being blocked, but I don't know where the sensor is located. Can anyone offer some suggestions?

konigstiger

See attached bulletin to replace, if need be, remove cover forward to 1.24

BOTUS

in the owners manual it say NEVER leave the auto wipers in the on position, stray sunlight as the vehicle manoeuvres can case them to wipe inadvertently and scratch the screen.

Mine does this - In northern hemisphere... if you have been travelling east and turn south circa 14:00 to 16:00 or from south to east around 11:00 to 12:00 is a usual sunlight angle to cause it

I think this is the same bit of kit that does the lights..... on most cars its a "rain light sensor" on the windscreen, with some refractometer to work out what's happening - there is a calibration process in STAR, but it sounds broken to me / and or always did it and you just noticed lately ?

ChuckinTucson

It only seems to be happening in the last couple of weeks. The reason I noticed it is because the Command screen dims when the headlights are on. The car has the original windshield from the factory, so that's not the issue at least. Looks like a trip to the mechanic may be in order to run a diagnostic on that rain/light sensor.

BOTUS

did you do the clock fix?
the screen going light to dark mode (if you have it in the default auto mode), is time related (or from the light sensor), had any software updates …. they screwed up and this is all muddled in later software releases....

ChuckinTucson

Not sure what the clock fix is. It didn't have a clock on the command screen, just below it - one that is analog. It goes dim and the "A" comes on the left side of the gauges showing the headlights are in automatic mode -- even if it's high noon out.

BOTUS

go in menus and check the vehicle date.... not seen confirmed if the NTG3.5 head unit has the same satellite fault as the pre facelift cars. I fully expect it has
if the date's wrong, could be worth asking Polar Bear if the clock fix update is doable on your later spec car...

the date and time the car thinks it is on, on NTG3.0 systems comes from a changed signal satellites put out.....but the car needs an update to make sense of the change after 19 year cycle due to a WNRO bug