This Preliminary Information communication provides information to the technician that a customer may request the factory Integrated Trailer Brake Control be bypassed and their aftermarket trailer brake controller be installed instead. Technician will need to gain access to the X185 or the X138 connector (varies with vehicle build; refer to Service Information) near the underhood fuse block, terminal 32. Circuit 47 ends at the body harness side of X185 or X138 terminal 32, which comes from the X61A junction block. Obtain enough Dark Blue 12 gauge wire to run from X185 or X138 to the 7-way trailer connector at the bumper. Attach terminated lead part number 13327155 to one end of the Dark Blue and insert into the chassis harness side of the X185 or X138 connector terminal 32. Run the Dark Blue wire in its own conduit along the frame to the 7-way trailer connector at the bumper. Remove circuit 47 from the 7-way trailer connector terminal ?C? and tape the bare terminal and attach to the harness. Attach terminal part number 12110853, located in Delphi Tray 4, to the other end of the Dark Blue wire, with the correct weather pack seal, and insert it into the 7-way trailer connector terminal ?C.? Install trailer brake controller harness General Motors part number 23184088 into Middle Bus Electrical Center (X61A).
