mcs

Hi Guys,

Me again with a question.

My A8 does not have auto lights or rain sensing wipers. It has the windscreen mount for the sensor which seems to have a blanking plate in it.

I would like to retrofit this sensor to give me Auto lights and wipers, as I miss the feature from my previous Mitsubishi.

Is it simply a sensor fit, plug in and code with VCDS? Do you know the correct sensor code? or will any VW rain/light sensor be the same?

Also, I am guessing I will require the switch for the headlights as well. Is there a specific one?

Thanks for any info. I did some research but it was hard to follow.

Mike

mcs

As an update to this,




I have bought a sensor, I have bought a small wiring harness and adapter from Audi which seems to be for the light only sensor to the roof harness.






The adapter changes the plug from the light only sensor to the rain/light sensor.

Now, my research is telling me to not connect the data wire to the roof module, but run it down the pillar trim to the J519 Central electrics module, and splice it into the data wire for the J400 Wiper Module.

Then the J519 gets coded to turn the rain/ light sensor on.

Of course, the Auto light switch was installed also.

Is this correct?

dvs_dave

I'd be interested to see how you get on with this. Mine has auto lights but not wipers so theoretically has the wiring already in place. Perhaps I just need to change the sensor and wiper stalk for the Auto one and then change the coding to get it going?

mcs

The wiper stalk isn't changed. It simply is altered by the coding to adjust the sensitivity of the sensor as opposed to the intermittent setting adjust.

I am awaiting the sensor itself to arrive and then I will have the car coded.

However, the data wire seems to be going to the roof module in cars with just a light sensor, but goes down to the J519 module with car that have a rain/light sensor.

We shall see.

In other news, when I instaled the wiring, I noticed my roof console has the buttons for Homelink. But no actual visible buttons. Does this mean the system is fitted? Where can I look to work out if I have the system?



Mike

Dville

Do you have the missing pics for this post?
or part numbers for the Harness?

my car is a 2006 an has the auto light switch but no sensor in the glass.
in auto the lights just stay on all the time.

mcs

asically the pre-facelift cars don't have a rain sensor until 05 production. If your central electronics module has an E at the end of the part number, it will not support coding for the rain/light sensor. You can try and code it but it will error out. This means you will have to replace it with a newer one. L through to S are fine apparently. Mine has Q on it.
You will also need to recalibrate the power steering column as it will lose its memory and wont adjust until it gets a reset using VCDS.

If you have auto lights, you won't need to change the switch, just the sensor and the sensor plug. Audi use the same cable to connect the sensor to the roof electronics module, for both the light only and the RLS. They just supply an adapter as the sensor end plug is different.

These are the part numbers

Rain and light sensor ref: 8K0 955 559 A
Sensor cable ref: 4E0970 291
Audi adapter: 1C0 973 119 B









I had to run the data wire directly to the central electronic module but the other two wires supplying power and earth to the sensor were at the roof module plug. Running a wire down to the central electronics matches the Audi factory wiring diagrams. the data wire goes down to the yellow/white stripe wire at the central electronic 09 module and it is a splice connection.

If your car has automatic lights before the sensor went in, then you will have to recode the roof module. This is how it works.

The G399 Light only sensor keeps its coding in the roof module.
The G397 rain and light sensor keeps its coding in the central electronic 09 module.

If you have a rain and light sensor, then you have to have NO coding for the light sensor in the roof module.

If your car had no sensors, then you will also need a switch with Auto written on it. This part is plug and play. Try to find one with the aluminium package ring on it as it looks better.

Mike

storka

yes one wire pillar trim to j519

Setdetnet

Found this when a search.
I would like to apply a mod using ODBeleven that requires the light/rain sensor
How do I know whether I have such sensor in my 2017 TDi ultra sport? Don't even know where il the sensor is? Pics would help
TIA good folk

Setdetnet

Mines an A4 B9

2004A8L

Mine is a 2004 and has both lights and rain sensor.
not sure uf it was factory or someone else did it.