#PIT5282F: Procedure for Installation of an Aftermarket Trailer Brake Controller or In Lieu of Factory Trailer Brake Controller

(Dec 19, 2019)

Subject: Procedure for Installation of an Aftermarket Trailer Brake Controller or In Lieu of Factory Trailer Brake Controller

Supersession Statement

This PI was superseded to add the 2020 models. Please discard PIT5282E.

Condition/Concern

Some customers may request to have an aftermarket trailer brake controller added to their vehicle, OR an aftermarket trailer brake controller added in lieu of the factory integrated trailer brake controller (ITBC) (RPO JL1).

Recommendation/Instructions

Obtain a trailer brake controller harness, GM Part # 23184088, as shown below.
Connect the harness to the MID-BEC (X61A). The MID-BEC is located under the I/P to the left of the steering column. The harness connection point (1) is illustrated below.
The trailer brake controller harness consist of 4 blunt cut wires and a label that calls out the wire colors and each wire’s function, also shown below. Use these 4 blunt cut wires to connect to the aftermarket trailer brake control.
Perform this step ONLY if equipped with RPO JL1 where the customer is requesting the factory trailer brake system be bypassed to add an aftermarket trailer brake controller. Locate connector X185 Or X138 (varies with vehicle build; refer to SI), which is 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.”

Warranty Information

If the customer wishes to have an aftermarket brake controller installed in their vehicle, it would be considered as a Customer Pay option.

From GM:

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.