Terminal assignment of connector
WARNING: This page is about a different car, the 2004 Volkswagen R32. However, it is still accessible from the selected car via links, so may be relevant.
1 - Voltage supply (terminal X)
2 - Ground (GND) (terminal 31)
3 - B+ connection terminal 54 (brake light, brake light switch)
4 - Parking brake warning light switch -F9-
5 - Diagnostic K-wire
6 - Not assigned
7 - Databus connection to Engine Control Module (ECM) and ABS control module (CAN-low)
8 - Databus connection to Engine Control Module (ECM) and ABS control module (CAN-high)