Service Trailer Brake System error after disengaging brake away trailer cable

[jdaddy33]

I somehow managed to accidentally pull out my travel trailer brake away cable while hooking up to my 2018 Sierra 1500 tonight (7 pin harness was already plugged in to truck). I didn't think much of it, just plugged back in the brake away cable on the trailer. However when I got into the truck I had an error notification saying "Service Trailer Brake System." I thought I just needed to clear the message and that it just popped up when it happened, however when driving the trailer back to storage I noticed my gain indicator on the dash when I would press the brake was not showing anything (usually the line moves from left to right the harder I push the brake). When I got to the storage I turned the truck off, and unplugged the 7 pin wiring harness and then plugged in and started truck up hoping it would reset, but no luck. Checked the fuse box under the hood in truck and do not see any blown fuses. Any ideas? Don't know much about those brake away brake cables on the trailer, but assume they are pretty straight forward. Would I need to do something special to reset it on the trailer? Or is there something that needs done on the truck to get my electronic brake controller working again.