Service Trailer Brake System
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2010 GMC Yukon XL, 2010 GMC Yukon, 2010 Chevrolet Tahoe, 2010 Chevrolet Suburban, and 2010 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
This message will be displayed when there is a problem with the trailer brake control system. If this message persists over multiple ignition cycles there is a concern with the trailer brake system. Take your vehicle to an authorized GM dealer to have the trailer brake system diagnosed and repaired.