070845001H

Service Bulletin
Bulletin No.:
07-08-45-001H
Date:
February, 2019
INFORMATION
Subject:
Procedure for Installation of an Aftermarket Trailer Brake Controller
Models:
2007-2014 Cadillac Escalade Models
2007-2013 Chevrolet Avalanche, Silverado
2007-2014 Chevrolet Suburban, Tahoe
2014 Chevrolet Silverado 2500/3500
2007-2013 GMC Sierra
2007-2014 Yukon Models
2014 GMC Sierra 2500/3500
2008-2010 HUMMER H2
with Integrated Trailer Brake Controller
This bulletin is being revised to include the Silverado/Sierra 2500/3500 and add 2013 and
2014 model years. Please discard Corporate Bulletin Numbers 07-08-45-001G (Section 08 –
Body and Accessories).
Important: Installation of an electric brake controller
and the wiring connections outlined in this bulletin are
the responsibility of the dealership or customer. These
repairs should never be charged to warranty. If you
have any questions, please consult with your District
Service Manager.
Some customers may request to have an aftermarket
trailer brake controller added to their vehicle, OR in lieu
of the factory integrated trailer brake controller (ITBC)
(RPO JL1).
Installation Instructions
Starting with the new 2007 full-size utilities and pickups
and 2008 HUMMER H2, there is no longer an electric
trailer brake controller pigtail harness.
To install an aftermarket trailer brake controller, use the
four blunt cut wires located near the data link
connector.
The following steps should be used to complete the
installation.
Four Blunt Cut Wires
Dark Blue
Circuit 47
Brake Signal to Trailer Connector
Red/Black
Circuit 242
Battery Power
Light Blue/White
Circuit 6311
Brake Switch Input
White
Circuit 22
Ground
Copyright 2019 General Motors LLC. All Rights Reserved.
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February, 2019
Bulletin No.: 07-08-45-001H
Important: This procedure will not result in any trailer
brake related display messages to be set. However,
ITBC diagnostics will continue to function. If an ITBC
fault is detected, a “Service Trailer Brake System”
message will be displayed on the driver information
center (DIC) and an appropriate DTC will be stored in
the ITBC module. The operator will still be able to
adjust gain and access the “Trailer Gain / Output”
display page in the DIC. However, the factory installed
ITBC system will not sense a trailer connection and will
not provide output to the trailer.
2005960
Important: Ensure that the ringlets are not interfering
with the UBEC cover.
1. Place the terminal on the larger of the two studs at
the front of the electrical center and secure with an
M8 nut. This is circuit #242 to stud #2, to power the
aftermarket trailer brake controller.
Important: The fuse is already present in the vehicle
to power the electrical trailer brake controller system.
2. ONLY For Vehicles Equipped with JL1 – Locate
connector X126 or X115 (varies with vehicle build;
refer to SI) near the underhood fuse block. Refer to
SI Document ID# 1849049 – I/P Harness-Engine
Compartment. Circuit 47 from the blunt cut wires
near the data link connector will end at connector
X126 terminal “G” or X115 terminal “B5.” Obtain
enough Dark Blue 12 gauge wire to run from
X126/X115 to the 7-way trailer connector at the
bumper. On one end of the Dark Blue wire attach
terminal part number 15304732, located in Delphi
Tray 8 and insert into X126 “G” or terminal part
number 15304720 located in Delphi Tray 19 and
insert into X115 “B5.” 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 and
insert it into the 7-way trailer connector
terminal “C.”
3. ONLY For Vehicles Equipped with JL1 – The
Red/Black wire, circuit 242, must be connected to
stud #2 of the 30 Amp fuse of the underhood fuse
block. This wire is located between the left fender
and the underhood fuse block.
2005527
4. Locate the trailer brake control circuits that are
looped and taped to the main harness under the
instrument panel.
2005561
5. Pull the trailering wire harness down.
Bulletin No.: 07-08-45-001H
February, 2019
Page 3
8. Break the tape on the red/black wire and pull it
toward the front of vehicle.
9. Remove the lid from the electrical center.
Auxiliary Power (Applies to All LD and 2007-2009
HD's Only) Without JL1
2005873
6. Match the vehicle harness label circuit functions to
the trailer brake controller jumper harness
functions.
Important: The color or wires to be joined together
may not match.
• Dark Blue Wire: switched power from controller
to trailer brakes
• Red with Black Stripe: fused vehicle power to
electrical brake controller
• Light Blue with White Stripe: Brake switch input
to power electric brake controller
• White: ground
• Orange: CHMSL (Center High Mounted Stop
Lamp) — not required with most systems
2005961
Circuit #742 for Auxiliary Power at the 7-way trailer
connector is no longer connected by the GM Assembly
Plant. If the customer desires auxiliary power at the
trailer connector location (i.e. refrigeration, battery
charger or interior light in the trailer), complete the
following steps to connect circuit #742:
1. Locate the red/black wire, looped and taped to the
chassis harness, below the brake master cylinder.
2. Break the tape and route the wire to the front of the
underhood electrical center.
2005877
2005962
7. After completing the under dash connections to the
electric brake controller, open the hood and locate
the red wire that is taped to the harness between
the underhood electrical center and the driver side
front fender.
Important: Ensure that the ringlets are not interfering
with the UBEC cover.
Page 4
February, 2019
3. Place the terminal on the smaller of the two studs
on the electrical center and secure with an M6
fastener. This is circuit #742 to stud #1 for auxiliary
power to the 7-way trailer connector.
4. ONLY for vehicles without RPO TP2 - Auxiliary
Battery, install a 40♦amp fuse to power the circuit.
Important: For vehicles equipped with RPO TP2 —
Devices powered by this fuse will drain the vehicle
battery if left connected with the vehicle not running.
Bulletin No.: 07-08-45-001H
Warranty Information
This installation procedure is to be performed at the
customer's request and at their expense. It is not a
warranty repair and a claim should not be submitted for
reimbursement.
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.
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