Posted 2009-02-02 7:22 PM (#98668 - in reply to #98664) Subject: RE: "service trailer Brake system" message on the DIC 2008 GMC SIerra
Expert
Posts: 3802 Location: Rocky Mount N.C.
Check your owners manual.... Then check for water or corrosion inside the trailer plug on the rear of the truck. Check for a blown fuse. Been in any salt lately? May be something on the same order as the oil change reminder.... Mine comes on every 8000 miles.... Check the manual for a "reset" procedure.
Posted 2009-02-04 1:04 PM (#98795 - in reply to #98664) Subject: RE: "service trailer Brake system" message on the DIC 2008 GMC SIerra
Extreme Veteran
Posts: 434 Location: Brooksville, Fl
Did you happen to have another plug installed? This happened to me every time it rained when I had an extra plug installed for the GN. I wasn't towing when it happened either. I took it back to the installer and he taped it up more or something (can't remember exactly) and it hasn't happened since. I have an 08 Chevy 3500. He made the comment that Ford just recommends soldering, period, to keep it from happening. Apparently, it's a somewhat common problem....
Posted 2011-10-05 12:07 AM (#138062 - in reply to #98664) Subject: RE: "service trailer Brake system" message on the DIC 2008 GMC SIerra
Expert
Posts: 3853 Location: Vermont
Further information:Some owners of a 2007-08 Silverado or Sierra with RPO JL1 may comment of a Service Trailer Brake System message displayed on the DIC. DTCs C1112 and/or C1114 will be set in the Trailer Brake Control Module (TBCM).TIP: This concern may occur with or without a trailer connected to the vehicle.Updated TBCM calibrations have been released in TIS2Web to improve TBCM diagnostics for a high resistance short to voltage concern. The Tech 2 can be used to monitor the TBCM Relay Feedback Signal parameter located under Chassis/Trailer Brake Control Module/Data Display to help determine if there is a short to voltage.The normal voltage reading is between 3.2-4.1 volts. If the voltage is higher, the updated calibration will help. If the voltage is lower, the updated calibration should still be installed. However, additional diagnostics may be needed to correct the concern.TIP: Refer to the latest version of PIT4595D and appropriate SI diagnostics for additional help.