The role of the Gateway (also known as the Data bus diagnostic interface J533) is the exchange of data between the CAN data bus systems ('powertrain CAN data bus', 'convenience CAN data bus' and 'infotainment CAN data bus') and the conversion of diagnostic data from CAN data bus systems to K-cable and vice versa so the data can be used by vehicle diagnosis, testing and information systems like the dealer VAS tools and Vagcom/VCDS.

For various reasons including power drain issues with third generation head units or the addition of new unsupported modules the CAN bus gateway must be upgraded to a newer revision. This guide covers the replacement of the CAN bus gateway in a 2005 MY06 Volkswagen Golf GTI. The upgrade replaces the 1K0 907 530 E (1K0907530E) with a 1K0 907 530 AA (1K0907530AA).

Full details and pictures/photos -
CAN bus gateway removing, installing and upgrading - Volkswagen Golf