Brake controller

Ok I have a 2007.5 GMC 3500HD diesel with the integrated brake control, when I hooked up to my fifth wheel it used to show on the DIC "trailer connected" and when I pressed on the brake the led dots would increase with the amount of pressure on the brake, now I'm getting nothing, no trailer connected or dots when pressing the brake, I have a trailer emulator that I plug in to the truck and all the lights go on except for the brake controller light it pulses, anyone have any ideas?

Thanks