Head lights doesn't turn on in Auto-mode in dark

[jgold47]

Originally Posted by lahermano

The lights used to work correctly.. i noticed this strange behavior since a couple of months.
Yes i think i do have rain sensors, though i never tested auto wipers since i bought my car.

is inpa a calibration tool for bmw ??
I am still learning a lot from this forum.

I had bought this car about 2 yrs ago.. and quite a few major problems i had and just with the help from this forum i was able to DIY all of these issue.
hopefully i will get this one too.

yeah, INPA is a diagnostic tool that BMW corporate uses. Its bootlegged to the public, but very easily obtained. its a powerful tool, so read up on it.

Bimmerforums has a great section on it.


the *RAIN*-light sensor is one piece. it uses the same sensor two ways. usually it fails together. the good news is that if your sensor fails complete, or blows a fuse, the car defaults to headlights always on for auto mode, and the wipers run all the time if in auto wiper mode. the way to test that is to move the wiper stalk 1 detent (one notch). If it wipes once (in the dry) and then stops, the module is probably still working.

Another test, turn the car on, turn the lights to off, then to auto in the dark.

Or, in the dark, when they are not on like they should be, hit the fog light button. When the car is in Auto mode, that causes the lights to come on. If they come right on, then we can probably eliminate the LCM (light module).

If I recall correctly, there are two adjustment that the light sensor takes. one is a calibration and the other is a sensitivity.

I will caveat that the RLS is weird. In the winter, my lights will go on in the middle of the day, even if its bright. Among things its looking at the angle of the light. Sometimes it goes on in my driveway in the morning which is shaded, but then i hit my street and its bright sun, and they stay on for like 10 minutes then go off.

Petulant is a word I would use.

welcome to BMW!