Hi, posting here rather than starting a new thread as this is my issue.

I have retofitted an RNS 510 to my Touareg and have the Media and Navigation screens show up in the MFD but have not been able to control the unit via the steering wheel controls. I do not own my own VCDS cable but have had a mechanic with one try various other Touareg owners radio coding including toggling on and off BAP, the steering wheel short press buttons etc. I have also tried downgrading the firmware from 5270 to 5238 but this did not resolve the issue either.

The actual unit is a 2016 model LED version which has part number 7E0035680B, HW-version 10. I believe it's a T5 transporter part number but the ebay seller advised that it was compatible with the Touareg. Could the fact that the part number is different be causing the issue? I have done a great deal of research through Google searches and was also wondering if my steering wheel control module may not be able to communicate with the RNS 510 due to an old version of transmission protocol, but the strange thing is the volume up and down controls work and the Nav and Media screens show up in the MFD. Would it be worthwhile going to the first version of firmware available and slowly upgrading the unit, as I believe the firmware gives the unit instructions as to which communication protocol it can communicate with?

Any advice is appreciated.