Dimming Running Daylights during Turn Signal

As ViĆ says - it depends on whether the headlights on your mk7.5 are controlled by the hex09 module, or the Light Control Modules (LCMs).

You can check which module controls the headlights by the setting for the Lasttyp channel for Leuchte2SL VLB10 and Leuchte3SL VRB21. If the factory value for these 2 x channels is not active, the car uses LCMs.

Don

jurucavw : Yes of course, I am always delighted to explain how "Leuchte-programmimg" works on MQB platform vehicles - like your mk7.5!

So - as you probably already know, each of the 35 x exterior lights on the car has its own "Leuchte-set" which controls how the lamp operates. A Leuchte-set consists of 19 x adaptation channels and the first channel (Lasttyp) as shown in your pictures is used to tell the Central electrics module how to set-up the lamp's power supply.

The clue for the purpose of the Lasttyp channel is in the names for the available options for this channel. If you look, you should find that the options are divided into 2 x broad categories; LED and non-LED. So, an important part of the function of the lasttyp channel is to tell the module what type of lamp is plugged into the fitting socket. It's probably too much information, but when an LED setting is used for this channel, the Pulse Width Modulation frequency of the supply voltage to the lamp is doubled (which is more compatible with LED lamps)

The second important purpose of the lasttyp channel is that it tells the module broadly how to set-up the general characteristics of the power supply for the lamp. These characteristics are linked to the settings for the 8 x Lichtfunktion channels in the rest of the Leuchte-set.

So- if you look at your pictures, the setting for the lasttyp channel is not active - and if you look at the Lichtfunktion values, they are also not active. This means that the Leuchte-set has been factory disabled - which consequently means that the Central electrics module doesn't control the associated lamps. Hence it's pointless changing values on these Leuchte-sets because there are no wires in the car's loom that connect the lamps to the pins on the Central electrics module (because the lamps are actually wired to the LCMs)

Hope this makes sense

Don

jurucavw : I should have said in my previous response that my explanation about Leuchte stuff is ALL guesswork!

There ain't anything official (no documents and no website DATA) in the public domain that I can find about Leuchte-programming. So, my writings are just supposition based on observations and guesses. If anyone has other thoughts, I am interested in hearing their hypothesis and of course, if anyone has actual information from VW, I would welcome them sharing the material - either on the forum, or via PM.



My suspicion is that the settings in these two adaptation channels (when active) refer to a Hexadecimal memory address within the module. My hypothesis is supported by the observation that the value of these channels is unique (i.e. there are no duplicates of the values in any of the 35 x Leuchte-sets, other than zero). I've also observed that when folk have sometimes entered incorrect values into these channels, strange error messages appear on the dashboard even though the lamps often work as programmed. In older hex09 modules, it was possible to disable fault monitoring to individual lamps by changing the settings in these channels to hex00 - but this no longer happens in newer modules.

So, my guess is that Fehlerort mittleres Byte DTC-DFCC and Lampendefektbitposition settings contain the memory address location and the Bit positions where the diagnostic module (i.e. Gateway module @ address hex19) can find fault data about each lamp - I think.