Jerry Riviello Beast Mowed NEPA Landscaping

I have a Chevy 3500 wt my service trailer wiring light comes on my dash spelled out with exclamation point, my left blinker and brake light don’t work only left side running lights are brighter on left side also. Tech said he’s getting power on all 7 prongs on my trailer hopkin connecter a snap on code reader saying it’s the brake control module and pressure valve and my code reader says c0800-5A control module not plausible please help