Originally Posted by touareg

Thought I would share this as it has bugged me a little for 3 years, then last 3 years bugged me a lot when I got a 957.


The problem, you buy an AUTO switch, and it plugs in and turns the headlights on all the time, or it does nothing, but turns on the lights in AUTO mode all the time, and triggers an error.

From the factory, my 2009 957 does not have dimming reviewer mirror, nor an auto switch.

Durametric has been frustrating since I bought it 6 years ago, and I now discovered it can not interact with many of the newer modules on the 957, as they support long coding, not the traditional short code from 10 years ago.

With the latest VAG-COM cable from Ross Tech and version 17 software. I was able to scan many more modules, read codes, do output tests, etc. I did not compare the two much but I think the DME is the only module I can not read that Durametric can.

For $15 I bought a used switch from a 2005 955 Cayenne S, find this part on ebay: 7L5.941.531C search that part. If you search for the 955 part number it is much more expensive.

I tried turning on the coming home, and the comfort light options, like I figured out on the 955 years ago, and confirmed I have under lighting in the MFI a option to do delayed lights off.

I plugged in my new to me switch, and it worked like a regular switch, no auto, no codes logged.

I was resigned to thinking something was wrong with my light sensor on my 957 from 2009.

At this point, I ran through some output tests, learned that each individual side marker and parking light can be controlled from that module. Interesting.

So I had one option left to check, Byte 04 Bit 0 Assistance Driving Light, that I assumed was the cornering lights for the touareg, as all the labels are verified for the touareg.

I checked it, hit apply in the vag com, and success!

ON Byte 04 Bit 0 Assistance Driving Light
ON Byte 04 Bit 1 Coming-Home
OFF Byte 04 Bit 2 Garage/Cinema Light
ON Byte 04 Bit 3 Comfort/Tip Blinking
OFF Byte 04 Bit 4 Emergency Brake Blinking
ON Byte 04 Bit 5 Comfort Interior Lightning

So in Byte 4, I have Bit 0,1, 3 and 5 checked. Bit 0 was the magic one.

I now have full delay settings in the MFI, remote turns on the interior lights when I approach the car at night. Auto headlights now on my non-dimming mirror, 2009 957.

There are a few other byte codes I want to mess with now, as I suspect there are more hidden features in this module related to lighting. For example still interested in the emergency braking and the garage cinema light (for turning off DRL when parking brake is on, I guess to run your car at the drive through with DRLs off)

Automatic driving light assistant
The driving light assistant is a comfort function.
Your Porsche’s driving light (low beam) is switched
on and off automatically, irrespective of the
ambient brightness.
Despite possible support by the driving light assistant,
it is the responsibility of the driver to switch
on the driving light using the conventional light
switch in accordance with the relevant national
regulations.
Activating the headlights using the driving light
assistant does not therefore absolve the driver of
responsibility for the correct operation of the
driving light.
The low beam is switched on automatically in the
following situations:
– Dusk
– Darkness
– Travelling through tunnels
– Rain (in conjunction with the rain sensor) - After a certain amount of wipes
– Highway driving - Over 87MPH
- Does not work in fog.

So I do have a few questions for others, that I don't remember ever happening:

If you do NOT have auto headlights, and at night you unlock your car, does the door side mirror lights come on? When do these normally come on? (I assume with headlights on, door open) I now have white light under the door mirror and under the door, I never really noticed before. This is with the headlight set to auto.





I am thinking now I can get the overhead console with the dimming switches, and do a plug and play on this.

My next thing to figure out is if I can control the "white parking lights" turn signals, as I did an output test on these, and was able to control them individually.

Originally Posted by Pochetemix

Quoting myself.

Yes, it works perfectly. @touareg , you're the man!!!

Originally Posted by tats

I have the same rain/light sensor with the manual mirror on my 2009 GTS.

I bought the auto switch from eBay and was able to change byte 4 coding as per the information above using a vag-com vcds. At last after several years I have the auto light on feature and have added a 15 seconds headlight delay for the coming home function. If your Porsche indy can't do it, maybe a VW/Audi guy can - the programming takes about a minute - select cent elec module 9, enter long coding, go to byte 4, enable bit 0 and I have 1, 3 and 5 enabled too.