Coming Home & Leaving Home

Created by Fredrik Andersen - Monday, June 29 2015, 15:05:42

This retrofit fits the following models:
Audi A3 8P Hatchback (2003 - 2013)
Audi A3 8P Sportback (2004 - 2013)


I have always loved this little functionality but as my car did not have light sensor I must admit that it did seem like a lot of trouble.

After replacement of my BCM (Body Control Module) when retrofitting my fog lights I was however able to activate the Coming Home & Leaving Home. The car however would think that it was always dark so the feature was working despite day or night.

Under "Installation & Guide" I am linking to a guide which can be used without replacing the BCM or installation of the light sensor.


1-2 hours

Installation & Guide

The installation was done by Discoboy (a user from

I unfortunately cannot be of much assistance with how the installation was done, but for those who wants to do the retrofit without Light Sensor and new BCM this should be the trick.

For those who wants to install Coming Home & Leaving Home the "correct" way I can help you with information about the parts I purchased.

Body Control Module
The BCM was purchased after retrofitting my fog lights. You can read more about that retrofit and about the different BCM types here.

Light Switch
I unfortunately just purchased a new light switch for the fog lights, now I need another one supporting Coming Home & Leaving Home + Automatic feature for the light sensor.

Cable Kit
The cable kit was created by discoboy himself. The plug for the Coming Home & Leaving Home which should be monuted on the light switch has part number: 4D0 971 636

Light & Rain Sensor
As already mentioned a couple of times, the Coming Home & Leaving Home was becoming a reality when I was going to install the light and rain sensor.

Installation of light & rain sensor required a new center rear mirror, sensor, cable kit and a new windshield. Read more here.


1. 09-Cent. Elect.
2. Coding - 07
3. Long Coding Helper
4. Byte 0
5. Activate Bit 7
6. Byte 2
7. Activate Bit 4

You will find a extended guide with pictures of the coding options for lights here.


1) Press the button to the bottom right on the light switch.
2) When there is light in the button, Coming Home & Leaving Home is active.
3) You can always deactivate the feature by pressing the button again.

Part numbers + Price

Description New Parts Original Parts Price Links
Light Switch 8P1 941 531 G 8P1 941 531 Q 68 € AZF
BCM 8P0 907 279 K 8P0 907 279 J 110 € ebay
CH/LH Stik 4D0 971 636 --------------- 7 € Audi
Pris i alt 185 €
The above price is not including shipping or installation.

The BCM was already purchased for the fog light retrofit and the light switch was as well purchased for the retrofit of light & rain sesnor, so all it all this retrofit was free. Only needed cables and plug.