I believe this will depend on your local traffic laws as some countries to not permit fog lights to be used as DRLs. But yes, it can be recoded. under Byte 17, Bit 4 (Note pre-facelift shown below Address 09-Cent. Elect.) Whether or not the vehicle will take LEDs replacement H11 bulbs is another question.

FAQ - Audi TT Mk2 (8J) Bulb Replacement & General...

Here's a references list for anyone who needs to replace a bulb in their headlights, side markers, fog lights, wing mirrors, tail lights, rear fog light or the third brake light assembly - Audi TT Mk2 Light Bulb List https://www.ttforum.co.uk/threads/audi-tt-mk2-light-bulb-list.1609466/ How To...

www.ttforum.co.uk

 

Are your headlights Halogens or Xenons?
If you have Xenons and have an "auto" position on the headlight switch you may find that the inner headlamps illuminate as DRLs in good light in the auto position, and automatically switch to outer headlamps as ambient light reduces.
My previous TT had halogens (which were dreadful), no auto position and no DRLs.

 

Was going to try that today but it’s been so gloomy. Hopefully better weather one day in the rest of the week!

 

If you have the LED DRLs, I don't believe this is possible. I don't think I've ever tried doing this on the TT (to even see if it's possible) but that's because I know for a fact it's not possible with coding on my A3 (which is a facelift 8P and has LED DRLs). On earlier cars w/o LED you can enable this, but with LED there is no such option.

Edit: The above is incorrect and I inadvertently stumbled upon how to do this...just today! After years of not knowing how this was done I uncovered this little tidbit while searching how to do something else entirely (rear light DRL in NA for the TT, still haven't figured out...).

Apparently the option you're looking for, for fogs with DRL if you have LEDs is to enable Byte 14, Bit 1 in Central Electronics (BCM). Do that and the fogs come on as DRL as well! Thanks to this post on Vortex for showing me that!

Audi A3 MY2011 Full brightness Parking Lights

Hi All, A scanned a new Audi A3 MY2011 model, and made some changes. But the owner asked me if it is possible to let the LED when functioning as Parking lights, to stay at full brightness. Can some body point me to the right byte/bit?? Here is the scan...

www.vwvortex.com

 

Updated my post above as I stumbled on how to do this on facelift/BCM cars with LED DRLs.