storka

I really don't think you have rain sensor fitted
That should have at least a q after it.
E is too early
When I fitted auto wipers ( long drama) I had to get a later model central electric module
At least q at the end and it worked. And that's after wiring and installing the sensor.
Found out by chance on a post somewhere.
I will see if I can find my old one and see what version was on it.
HAve not seen one with auto lights without auto wipers.
Although my auto lights worked with the older cent elec.
There are two different light sensors for the windscreen
One is a light rain sensor one is light sensor only.
You may have to check your sensor part number as it may have only come with auto lights.
Or as you said check your option codes

jlbell

That is very interesting, especially if you haven't seen an A8 with auto lights without auto wipers. I will go hook the car up again tonight to see what I can find out. Do you know if there is a test or function that will show the part number for the sensor/sensors in VCDS?

dvs_dave

For some wierd reason the 04 USA models don't have the rain sensor, light sensor only. Mine is the same.

You can retrofit it fairly easily though. There's a couple of "how to" threads on here if you search.

2004A8L

Are we talking about the wipers rain sensor that starts the wipers when it rains ? lol

Mine is 2004 and it has that option and it also works too

jlbell

This adds even more to the confusion. I honestly think it is all based in the coding, and/or modules accepting the coding. I have both the light sensor which is the extended part of the rearview mirror and the round circle which rests inside of the rearview mirror housing. I honestly think they prepared (fitted necessary components (sensors), but a module that can not accept the coding) for it but only "activated" it after a certain build date. Im going to have to look into the electrics pdf I have.

storka

So I take that as a no that auto wipers is on your options list ?
There are positively two different sensors available as I said.
As DVDs Dave it should be fairly easy to retro fit.

Pothole5000

That goes against everything I know about German cars and options.... Maybe on a Honda but Audi seems to love making 10 different wiring harnesses for each model.

jlbell

I have worked on many german cars, mainly BMW, but they all have the same layout/design when it comes to sensors and modules, however you are correct when it comes to the communication between them via wiring harnesses. Also I think you are getting wiring harnesses and sensors/modules confused. The rain/light sensor is linked to either or both the 09 (central electrics) and/or 38 (roof electrics). If they are linked both to 09 and 38 then if one coding is incorrect or doesn't include rain sensor coding then their is a high possibility that it will not work, because the two are not communicating with the common coding. Finally this was taken from the 2004 service training of the A8, which explicitly mentions a rain and light sensor:


This is why at the beginning I asked to see who has rain sensing wipers to provide their code to 09, which includes wipers and rain/light sensor and their code to 38. Just to try and see if changing the code, to a verified functioning code of a functioning rain sensing wipers, will make mine work. Sorry if anything is confusing, its a bit late and I'm a bit tired.

storka

Auto light rain sensor is 8k0 955 559
Can you see that in 09 cent elec
In subsystem 2 regenlichtsensor
If not give me all the part numbers in 09

MP4.2+6.0

+1 The D3 harness is supposed to be customized for each one built--exactly wired for the specific options and equipment in the specific car.