[sambam]

I had the Service Trailer Brake System message randomly for the past 3-4 years. About 2 weeks ago, it started coming on every time I started the truck and put it into gear. I looked for bad grounds and other connections that may be causing the problem, but no luck. So, did a Google search and found some interesting stuff. As Kevin said, there are many solutions to the problem, but I found a lot of guys fixed their problem by replacing the trailer brake relay. So, I bought one and put it in. Didn't solve the problem. I was quickly running out of time with a camping trip coming up this week, so took the truck to the dealer. Turns out there was a TSB for this code and the Trailer Brake Control Module Kevin speaks of is the culprit. It didn't need to be replaced, just reprogrammed with different parameters. I've had the truck almost a week since the "repair", and so far, so good. My truck is an '07 and this TSB affected '08's as well according to the copy I got. Hope this helps.