Yeah I know this is the Ford page (I drive a Ford), but I see more guys on the Ford page that know what they are taking about, and reply to messages. My Mother-in-law has a 2007 Chevy Silverado 3500 with the integrated trailer brake system. When she bought the truck she had a ball installed in the bed and had a 7-way plug added in the bed by the same people. My truck has the same setup and is wired the same and I have no problems with it. The dash tells her to "service trailer brake system." She gets this error message both when the trailer is connected and when it is not. When it is not it usually gives you the message when you put it in reverse for the first time after starting it. When the trailer is connected it is more unpredictible. Sometimes I'll get the message and then it goes away and everything is fine, other times it stays there and as a result there are no trailer brakes. I have had it working fine going down the highway until I use the turn signal and then the message will appear and then go away once the turn signal is turned off. Fuses all appear to be fine. We have had this truck into dealers several times, but for some reason they can never get the truck to act up on them. I'm hoping someone on this page may have run across something similar and solved the problem

 

Its the Chevy demons..... it sounds like its a wiring issue. somewhere in the aftermarket wiring harness for the trailer brakes somethings not right. could be defective wire harness or installed poorly. i would see if you can find a instruction manual for that style trailer brakes and follow step by step and trace out all what was done to install the brake system. really it sounds like you have to start all over again.

 

A bad ground on a trailer light system will do all sorts of crazy things. I would check that first. It is also possible to be a short in the harness feeding the new plug.At least you have a limited amount of wires to check.

 

The new plug is spliced into the wiring for the factory installed plug right behind the bumper. The connections appear to be sodered and are heat shrinked. Also this poblem is with any trailer I connect the truck to, and these same trailers do work fine when I pull them with the Ford. I'll give the wireing a good once-over and see it I can find any bad grounds. Thanks for the replys, the Chevy guys still arn't saying anything.

 

if i remember right my uncle had that same problem with one of his chevy's (i know it was a trailer brake issue and it said something but idk what) and it ended up that the plug had gotten some water in it and the connections were a little rusted so he scraped them clean and it worked. now his was a bumper pull so its much more likely that it got water in it but id say check it just as a possible quick fix