Pin 2 on each connector is for Turn/Brake, to Brown on the light. Passenger = Blue/White Driver = Blue/Violet Pin 3 4 White is feedback signal to the BCM Pin 4 3 Black is ground. Not for a trailer connection, but I did tap into pin 2 for each side's turn/brake signal.. My RH passenger side with a Tee harness tapping the Turn/Brake signal. Source: https://www.chevybolt.org/threads/bolt-euv-2023-break-light-wire-color.57143/