My Headlight behaviour - please explain...

[yuko3d]

Hello,
I'm trying to diagnose/understand the way my headlights behave and if it's normal, so here goes:
Car is a Canadian 2003, single Xenon without automatic headlights .
What I noticed is that in normal driving, my Fogs are always on - which is normal for Canadian market I suppose. But my Low Beams (Xenons) turn them selves on and off. I noticed it when pulled up closely to a car in front of me, I can see my Xenons going on and off. At some point I believed that I have automatic headlights which turn themselves on when it's dark, but the "light sensor", which I believed was a small nipple in the middle of my dashboard, played games. After further reading I kind of concluded that I do NOT have automatic lights, as my main switch has no Auto written on it, neither I have a rear view mirror with some sensor attached to it, simple plain mirror. And the thing on dashboard does not control my headlights.
So WHY are my Xenons turn themselves on and off randomly. I still believe they have tendency to stay on when it's really dark, but maybe it's just my fogs that are really bright.
I started to play in VCDS and will keep playing with adaptations and coding to see If I can find a way to have my Xenons always ON when my engine is started.
I know I'm suppose to turn my lights on by myself, but since half of the time my Xenons are on sporadically, they might as well stay on for the whole drive.

Sorry for long post, hope my questions is clear

Thanks for any help

[5ktq]

If you change CECM coding from "Canada" to "northern countries" (ie. scandinavia) it uses the low-beams as daytime lamps instead of the fogs.

is the turning on and off linked? like both sides do it together?

My feel is probably there is a problem with central electronics module. it's under the panel by your knees, if it gets wet because there is problems with the seal/lid on the ECU box and lights behave erratic.

[yuko3d]

Both sides work together, Xenon operation is fine using rotary switch.

I think I'm onto something,
This morning, started the car, Xenons Lit and stayed on, rotary switch was at "O" all the time. Drove with VSDC plugged, and, Rotary switch reading block 6 was displaying Position 5! No matter what which position I was setting it, also got 01800 - Light Switch (E1) Implausible Signal, so I guess I'll start from there, swapping the switch.

I'll try to troubleshoot-repair/replace the switch, eBay seems to have them

[5ktq]

Sounds like a good place to start.

[imnuts]

My car did that (lights on with switch off) randomly for a while. Eventually I bought a new switch, replaced it, and the problem hasn't come back yet.

My guess is that the module fails to lights on if it's getting a bad signal from the switch for safety reasons. Better to have lights when you don't need them than the other way around.

Sent from my Pixel XL

[yuko3d]

....
My guess is that the module fails to lights on if it's getting a bad signal from the switch for safety reasons. Better to have lights when you don't need them than the other way around.

Sent from my Pixel XL

Yeah exactly my reasoning on this too. Bad signal, in my case, sets switch reading to Position 5, which I believe is everything on with fogs. Or maybe it's the other way around, Control module ignores the reading from bad switch and goes all out, lighting my xenons - which is what I want for my daily driving. Have my lights on and not to switch them on manually as I always forget to put them on anyway since my dash is always lit. (Scandinavian settings turns my dash off btw, which could be an option to always remember to put them lights on)

[5ktq]

interesting, i'm pretty sure on mine scandinavian is dash + park lights + headlights, which is pretty silly. daytime lights that light dash and park lights is .. wtf audi

though I have '02, so early power module. Maybe later ones changed how they operate somewhat. Pretty sure the later ones have more options, anyway.