"Service trailer brake system" on 2016 GMC

[jabres]

Have a 2016 GMC 3500, 6.0 gas job with 57K miles.
Constantly now my computer screen beeps "Service Trailer Brake System", even when no trailer is hooked to truck..
took to my local trailer guy, he checked my plug port where trailer lights plug in, and we checked all fuses. he said neither is the problem.
he says its either the factory built trailer brake controller that was built in dash, or the "Module" that is up under the spare tire. Anyone ever have this issue?
He said it would be a guessing game for him. I hate to take it to the stealership for diagnosis though....

[Dave_H_M]

thanks for the update, i care about them.

[jabres]

Not that anyone cares lol, but I figured I would update this post incase someone searches this in the future.
I ended up trying out the cheapest and easiest part to replace, bascially throwing parts at it, and bam it worked. My factory trailer brake controller was the problem. I had one sent via Amazon, $43 later changed it out and works like new. No more stupid computer telling me to service trailer brake system. I love my GMC's, but kinda crazy the factory brake controller went bad on a 3 year old truck with 57k miles. O well, could be worse

[deltabravo]

Pressure transducer failed on my 2009 back in about 2011.

[Beaker]

Had that problem on my 08. Controller replaced under warranty.

[Fisherman]

Maybe a bit of road salt corrosion happening causing electrical gremlins to surface.

[jabres]

Like2build- wish it was, just this year GMC was 3 years 36000 miles, which is kinda a joke.

[neil57]

Friends truck had same issue, was the ground on the module up by spare tire. It’s not expensive to just replace it.

[ksss]

My 08 was doing that this Winter first time I had seen it before. Moisture or issue at the rear plug is cause.

[LIKE2BUILD]

Are you not under warranty? If you are I'd take it to the dealer and let them sort out the issue.

[ScottG]

I would take apart the connectors behind the bumper and make sure none have moisture in them. Assuming there isn't a failure with the brake controller, it's seeing a connection to the brake actuating wire at the trailer connector. That could be moisture, rodent damage, etc.