Help with retrofitting auto lights

[Somerandomguy]

Has anyone done this mod and could provide some advice?
I have fitted the sensor (i used 4e0955559a) , changed the light switch and run a wire down to the central electric module and powered it from the roof module.

Now, the auto wiper function works great, but the DIS always throws an error that the sensor is faulty when I put it into auto lights.

Do I have a dodgy sensor? (If so then wouldn't the wipers also not work) or have I missed something out.

This is on a 2004 D3, and I did note that the circut diagrams only refer to the sensor as a rain sensor, not rain and light, but that may be a red herring....


Thanks