Auto headlights almost always on in daylight

[smithcorp]

Bit confused about the daytime running lights option versus the headlights on Auto coming on and staying on in daylight. However, I checked myself last week. Started the car early in the morning (near sunup). Lights set to Auto, come on and stay on as I drive into the daytime out to Camden.

Then, at lunchtime, I start the car in full daylight and drive locally (no more than 80kph at any time), but the lights come on and stay on on a bright Sydney day. Got me stumped. I don't mind it too much (safer I suppose), but it annoys my wife and she's forever turning the lights off Auto.

I haven't contacted the dealer about it - I figure it can wait until first service to raise it.

[NZTiguan]

Smithcorp, are the dash lights on as well ? or just the headlights ? in which case are you sure you don't just have DRLs active ?

[aussietig]

Bit confused about the daytime running lights option versus the headlights on Auto coming on and staying on in daylight. However, I checked myself last week. Started the car early in the morning (near sunup). Lights set to Auto, come on and stay on as I drive into the daytime out to Camden.

I don't think it's confusing at all:

They are meant to be the complete opposite of one another!

Lights set to 'Auto' - will automatically turn on main headlights when light sensor detects there's not enough day light.

DRL option if you also have 'Auto' on - will only turn on DRLs if main headlights are not switched on (i.e. when light sensor doesn't detect there's not enough day light). So as the name suggests during the day when outdoors and not indoors.

Conclusion: you actually have both on at the moment, so that's why it feels like they're on all day and night.

However, it's a lot easier to tell with xenons, as xenons are not normally coded to function as DRLs. Nor would you want to!

100% confirmation of this would be to either analyse your module 9 long coding via a VCDS scan.

Alternatively, a little experiment you can do without turning DRL option off completely is to dim your headlight's output (say to 50%) when they are functioning as DRLs.

If you can physically see that your headlights have dimmed during the day (outdoors), then they're DRLs. But again, you need VCDS cable to do this!

[NZTiguan]

The simple test is this (assuming your headlights are set on AUTO):

If the headlights are staying lit, check to see if the dash lights are ON, if they are the AUTO has switched them on (and if it's bright daylight and has been for some minutes then you have a problem somewhere), if they're NOT then it's the DRLs running and NOTHING to do with the AUTO sensor.

[Dartiguan]

I have Bi Xenons, seem to have DRL going and yet do not have the option in my MFD to turn it on or off? Perplexing! So is the MFD option for DRL a VCDS issue as well as the option of just having DRL with Auto.

Too clever by half is my view of this vehicle. VW standardises physcal production options to cut costs for their operations but the proliferation of software issues is becoming annoying when you have to interpolate their meaning. A logic diagram would have been helpful in the manual in this area. I am not a fan of the VW manual as you might have guessed.

Aussietig, why is it NOT a good idea to have DRL with Bi Xenons, is it because of life expectancy of Xenon bulbs and expense or another reason you have for saying this?

[aussietig]

Aussietig, why is it NOT a good idea to have DRL with Bi Xenons, is it because of life expectancy of Xenon bulbs and expense or another reason you have for saying this?

Yes ... life expectancy reasons, especially if your default DRL is dimmed! Not good for the ballast.

For example: Mine was set @ 92% when I first checked via VCDS! Don't know why that number.

But not easily detectable a 8% drop in output!

[smithcorp]

Thanks for the clarifications. I will look to see if DRL is activated via the MFD and report back.