PFL Auto-light retrofit - Ambience lighting short to ground error

Hi all,

I have an Elegance model with the rain/light sensor and auto-wipers from factory. I am trying to retrofit auto lights but getting a fault when trying to code the 'coming home' lights. 

I've installed a genuine PFL auto light switch (the one with the tunnel light icon) and added a repair wire from pin 2 of the light switch connector, to pin 14 of the control unit connector as per the below diagram. 

I have then activated auto-lights with VCDS and everything is working fine, apart from the 'coming home' lights.

When I set the coming home lights to use the light sensor (byte 2, bit 4), I get the following fault showing up - anyone know a way to get around this?

Address 09: Cent. Elect.        Labels:. 3C0-937-049-30-H.lbl
   Part No SW: 3C0 937 049 AJ    HW: 3C0 937 049 AJ
   Component: Bordnetz-SG     H54 2202  
   Revision: 00H54000    Serial number: 00000005407638
   Coding: E18E9F031014140040110D000000000000097F075C400020000000000000
   Shop #: WSC 73430 790 12345
   VCID: 71E963C668A91CCCE7-8024

   Subsystem 1 - Part No: 1Z2 955 119 C  Labels: 1KX-955-119.CLB
   Component: Wischer 111207 022  0601  
   Coding: 00055223
   Shop #: WSC 73430  

   Subsystem 2 - Part No: 1K0 955 559 AF  Labels: 1K0-955-559-AF.CLB
   Component: RLS     271207 046  0204  
   Coding: 00471077
   Shop #: WSC 73430  

1 Fault Found:
02390 - Control / Regulation for Ambience Lighting (E400) 
            009 - Open or Short to Ground
             Freeze Frame:
                    Fault Status: 01101001
                    Fault Priority: 5
                    Fault Frequency: 1
                    Reset counter: 145
                    Mileage: 137761 km
                    Time Indication: 0
                    Date: 2005.09.13
                    Time: 31:63:63

             Freeze Frame:
                        ON
                    Voltage: 12.00 V
                        ON
                        ON
                        OFF
                        OFF
                        OFF