Trailer tow circuit for Cadillac XT4 I (2018-2023)

AUXILIARY UNDERHOOD FUSE BLOCK BATTERY FUSE BLOCK BATTERY POSITIVE VOLT BLK WIRE BLK/WHT WIRE BLU WIRE BLU/WHT WIRE BODY CONTROL MODULE (LOWER CENTER OF DASH) COMPUTER DATA LINES SYSTEM DATA 1 (+) GRN/VIO WIRE GRY/BRN WIRE HI SPD GMLAN SER HOT AT ALL TIMES INSTRUMENT PANEL FUSE BLOCK LEFT TRAILER LEFT TRAILER STOP/TURN SIGNAL LAMP RELAY NCA WIRE PARK LP RLY CTRL RED/BLU WIRE RED/WHT WIRE RED/YEL WIRE RIGHT TRAILER RIGHT TRAILER STOP/TURN SIGNAL LAMP RELAY SIG GND TRAILER CONNECTOR TRAILER PARK LAMPS RELAY TURN SIG LP CTRL UNDERHOOD FUSE BLOCK WHT WIRE YEL/GRY WIRE