Does anybody know how Skoda auto headlights really work?

**K1W1** · 20-11-2012, 08:44 AM

I pulled up behind a car on the way to work this morning (auto headlights on) and noticed that I had headlights plus LEDs plus fog lights on so as it was a completely clear blue sky with perfect visibility I manually turned the light switch off.
As I was nearing work I turned the switch back to auto and the lights came back on but a quick check in the front windows of the office showed that it was headlights only plus LEDs(not fogs).
I have had situation sin the past where I have noticed that the fogs and headlights have been on but most of the time it's only headlights.
How do these things decide whether to work and what lights to turn on?

**zei20t** · 20-11-2012, 08:46 AM

fog lights aren't activated with the auto position (never for me) so maybe that was your cornering lights if you had your steering wheel slightly turned or indicator on?

anyway, AFAIK its the sensor in the rear mirror that activates the headlights, so when you go into a tunnel, carpark blah blah. or its the sensor in the middle of the dashboard.

**K1W1** · 20-11-2012, 11:12 AM

Originally Posted by zei20t

anyway, AFAIK its the sensor in the rear mirror that activates the headlights, so when you go into a tunnel, carpark blah blah. or its the sensor in the middle of the dashboard.

It's the sensor on the dash as far as I know. The one on the mirror is only for the wipers. It works by measuring changes in refraction of the light signals it sends out that is why you have to manually start the wipers sometimes if you start driving with the windscreen wet. In that case it measures the wet as that standard setting.

**zei20t** · 20-11-2012, 01:17 PM

Originally Posted by K1W1

It's the sensor on the dash as far as I know. The one on the mirror is only for the wipers. It works by measuring changes in refraction of the light signals it sends out that is why you have to manually start the wipers sometimes if you start driving with the windscreen wet. In that case it measures the wet as that standard setting.

I didn't mean the sensor on the windscreen behind the mirror. I mean the light sensor IN the mirror, next to the green light that auto dims the mirror. that's a light sensor, its the one that activates the CH/LH lights AFAIK. but I don't have a workshop manual to get all diagnostics

**BlackSuperb** · 20-11-2012, 02:16 PM

Originally Posted by zei20t

I didn't mean the sensor on the windscreen behind the mirror. I mean the light sensor IN the mirror, next to the green light that auto dims the mirror. that's a light sensor, its the one that activates the CH/LH lights AFAIK.....

I though it just does as you say, dim the mirror (including side door mirrors in my case) and only the mirror, when it senses the headlights from the car behind. From the manual:

Note
■ Automatic mirror dimming operates only properly if the sun screen for the rear
window in the housing on the luggage compartment cover is not in use or the
light striking the interior rear-view mirror is not affected by other objects.

The manual also says about auto headlights:

If the automatic driving lamp control is switched on, the light is regulated with
the light sensor in the rear mirror holder. If the light intensity drops below the set
value, e.g when driving during the day into a tunnel, the low beam and the side
lights as well as the licence plate light come on automatically. If the light intensity
increases again, the lights switch off automatically

The "rear mirror holder" would be the bit attached to the windscreen that senses rain as well.

**zei20t** · 20-11-2012, 03:03 PM

damn czechlish, its all a bit confusing lol

**BlackSuperb** · 20-11-2012, 08:49 AM

Didn't realise that fog lights were connected to the auto function. Maybe a "Ctrl Alt Del" of the light sensing module is in order. However one may do that is a mystery tho.

I had a similar thing happen to my auto wipers. The auto function stopped working for two days then it was all good ever since. Ones and Zeros are the culprits.

**Inego** · 20-11-2012, 09:34 AM

Interesting about the fogs - they've never come on for me, so perhaps its an MFDS setting on your car? The two times I've needed the fogs in the last almost 3 years I've turned them on manually.

As for the wipers, my experience is that the sensor needs a change in state for the function to operate, or at least in some circumstances eg. if the screen is already wet, I need to switch them manually, but if it starts raining whilst driving, the auto function works.

**K1W1** · 20-11-2012, 11:06 AM

I've noticed the fogs on probably twice previously both times in the morning when I have been behind cars at the lights (stationery, wheels pointing straight ahead, no indicators). It annoys me I hate people who drive with their fog lights on when not required and I'm concerned that I'm driving with them on more than I think.
BTW: This morning when I first noticed them on (reflected in the back of a ute) I turned the lights off and then back to auto and the fogs came on again so I turned them off again.
I've noticed that VW group cars seem to be the most likely to have their lights on in the mornings as well. I suspect that whatever settings the auto sensors have they are common across the whole VW group range.

As far as using the fogs is concerned where I live I need them a lot at various times of the year front and rears. We can be down to 5-10 metres of visibility regularly here. You literally have to navigate at walking speed from one cats eye in the centre of the road to the next at times.

**BlackSuperb** · 20-11-2012, 11:25 AM

Originally Posted by K1W1

I've noticed the fogs on probably twice previously both times in the morning when I have been behind cars at the lights (stationery, wheels pointing straight ahead, no indicators)......

This might be out of left field but could it be the refraction of the car's rear panel in front of you gives you the illusion that you have two rows of lights on, ie headlights and fogs, but in reality it's only a reflected double image of just headlights?

I have noticed it before with mine.....

Have you actually seen them both on in AUTO by getting out of the car?