[BillyP]

My 2007 roadster (8J9 EA113) will turn on the xenon headlights as part of the leaving home function. Totally unnecessary since this happens in daylight as well (no light sensor). Using VCDS and module 9-Electrics I see that byte0 bit 5 is not set. Still the leaving home function is active. This has been irritating me for years

I did find a solution on a forum but this was for mk2 with LCD head unit.
Any help will be greatly appreciated.

 

[SwissJetPilot]

See if this post helps. The VCDS screen shots are from my 2007 3.2 VR6 Roadster with Xenon headlights -

FAQ - VCDS Module 09-Central Electronics & Long Code...

Posted from a German Spec 2007 3.2 Quattro Roadster - I think it's safe to assume not all TT's have the exact same options in coding, so yours may be different. This is just to give you an idea of what may be available under the Centeral Electronics module and where to find it if you want to...

www.ttforum.co.uk

 

[TT'sRevenge]

First of all, there's no aftermarket stuff on this car like an aftermarket alarm or RS, is there? Just want to make sure one of those is not responsible for the lighting behaviour.

If no aftermarket stuff... What does Byte 2 Bit 4 look like?

I think prior to the white DIS you would not have the option for CH/LH in there--instead in those older cars CH/LH was determined by a small button on the headlight switch. However if you don't have the light sensor I don't think you had this from the factory, so you won't have that light switch either.

It's possible a PO added this feature to the car. Without that light switch button though, on the older cars to enable CH/LH what you would do is also have to do some wiring to make it work (in addition to coding). It might be that the wiring added (if there was any) is what is causing it to stay on.

Keep in mind that the Central Elec. are 8P modules so this guide on how to do it on a pre-facelift A3, may help you understand (and possibly undo) what would have been required to add it to a car that didn't have it from the factory and doesn't have the button on the light switch:

Coming Home Lights

Enable Coming Home & Leaving Home Lighting on 8P A3 If your car did not come with Coming Home & Leaving Home Lighting you can enable it by following this procedure. You will need one repair wire 000 979 009. It is not necessary that your car have auto-lights\wipers or auto-dimming mirrors to

audiretrofit.quinlivan.net

Apart from finding any wiring was added, you may try to cycle the option in VCDS--turn ON the feature, write the coding and exit, cycle the ignition and all that, and then go back in and turn it OFF and see if that changes it.

You can also search around regarding adding/using CH/LH on pre-facelift 8P A3s online (will likely get you hits from Vortex and also Audi-sport.net)--the information should be about the same because again these are actually 8P Central Elec. modules in Mk2 TTs.
Here's a big thread about it on the latter site mentioned:

Coming Home & Leaving Home Lights Enabled

I was over at my parents' house this afternoon waiting for my brother arrive down with my new FBMFSW (I got it delivered to him during the week) and got a bit bored, so I decided to have a go at getting the Coming Home & Leaving Home Lights to work. My car didn't have them from the factory and...

www.audi-sport.net

 

[MT-V6]

Do this in reverse How to: enable coming/leaving home lights on 2007 TT

 

[GavinT]

Mine has a wee button down next to the DRL brightness control. If the red light is on the Stay on function is on, I just switched it off. Mind is a 2008 or 2009 though.

 

[TT'sRevenge]

Mine has a wee button down next to the DRL brightness control. If the red light is on the Stay on function is on, I just switched it off. Mind is a 2008 or 2009 though.

Yes, this is the button I was talking about, above. Cars with a red DIS will have this; cars with the updated white DIS will have the option in the DIS/MFD. However if one has a red DIS car and doesn't have the button, it's most likely it has been added by a previous owner (presuming one is not the original owner) by using the methods linked to above.