Volvo S80 II (2006-2010) Trailer tow circuit, 4-pin

4-PIN TOW HITCH CABLE HARNESS (UNDER CENTER OF REAR BUMPER) BLK WIRE BLK/ORG WIRE BLU WIRE BLU/RED WIRE BRAKE LIGHT CONTACT (AT TOP OF BRAKE PEDAL ASSEMBLY) BRN WIRE CENTRAL ELECTRONIC MODULE CENTRAL ELECTRONIC MODULE (BEHIND RIGHT END OF DASH) COMPUTER DATA LINES SYSTEM FUSE G-TRM (LEFT REAR CORNER OF LUGGAGE COMPARTMENT) GRN WIRE GRY/ORG WIRE HOT AT ALL TIMES LEFT REAR LAMP HOUSING ORG/ WIRE REAR ELECTRICAL MODULE (LEFT REAR OF LUGGAGE COMPARTMENT) RED WIRE RED/BLK WIRE RED/BLU WIRE RED/WHT WIRE RIGHT REAR LAMP HOUSING STOP TRAILER MODULE (TRM) (LEFT REAR OF TRUNK) VIO WIRE VIO/BRN WIRE VIO/ORG WIRE VIO/WHT WIRE WHT WIRE YEL WIRE