Page 42 of 594

Black plate (36,1)GMC Sierra Owner Manual - 2011
1-36 In Brief
Roadside Assistance
Program
U.S.:1-800-GMC-8782
(1‐800‐462-8782)
TTY Users (U.S.): 1-888-889-2438
Canada: 1-800-268-6800
Mexico: 01-800-466-0801
As the owner of a new GMC, you
are automatically enrolled in the
Roadside Assistance program.
See Roadside Assistance Program
(U.S. and Canada) on page 13‑8
or Roadside Assistance Program
(Mexico) on page 13‑10 for more
information. Roadside Assistance and OnStar
(U.S. and Canada)
If you have an active OnStar
subscription, press theQbutton
and the current GPS location will
be sent to an OnStar advisor who
will assess your problem, contact
Roadside Assistance, and relay
your exact location to get the help
you need.
Online Owner Center
(U.S. and Canada)
The Online Owner Center is a
complimentary service that includes
online service reminders, vehicle
maintenance tips, online owner
manual, special privileges,
and more.
Sign up today at:
www.gmcownercenter.com (U.S.)
or www.gm.ca (Canada).
OnStar®
For vehicles with an active OnStar
subscription, OnStar uses several
innovative technologies and live
Advisors to provide a wide range
of safety, security, navigation,
diagnostics, and calling services.
Automatic Crash Response
In a crash, built‐in sensors can
automatically alert an OnStar
Advisor who is immediately
connected to the vehicle to
see if you need help.
Page 408 of 594

Black plate (114,1)GMC Sierra Owner Manual - 2011
9-114 Driving and Operating
Trailer Brakes
A loaded trailer that weighs more
than 900 kg (2,000 lbs) needs to
have its own brake system that
is adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted, and
maintained properly.
If the vehicle is equipped with
StabiliTrak, the trailer cannot tap
into the vehicle's hydraulic brake
system.
The trailer brake system can tap
into the vehicle's hydraulic brake
system only if:
.The trailer parts can withstand
20 650 kPa (3,000 psi) of
pressure.
.The trailer's brake system
will use less than 0.3 cc
(0.02 cubic inch) of fluid from
the vehicle's master cylinder.
Otherwise, both braking systems
will not work well or at all.If everything checks out this far,
make the brake tap at the port on
the master cylinder that sends the
fluid to the rear brakes. Use only
steel brake tubing to make the tap.
Auxiliary Battery
The auxiliary battery provision can
be used to supply electrical power
to additional equipment that may be
added, such as a slide-in camper.
If the vehicle has this provision,
this relay will be located on the
driver side of the vehicle, next to
the underhood electrical center.
Be sure to follow the proper
installation instructions included
with any electrical equipment that
is installed.
Notice:
Leaving electrical
equipment on for extended
periods will drain the battery.
Always turn off electrical
equipment when not in use
and do not use equipment that
exceeds the maximum amperage
rating for the auxiliary battery
provision.
Trailer Wiring Harness
The vehicle is equipped with one of
the following wiring harnesses for
towing a trailer or hauling a slide-in
camper.
Basic Trailer Wiring
All regular, extended cab and crew
cab pickups have a seven‐wire
trailer towing harness.
For vehicles not equipped with
heavy duty trailering, the harness
is secured to the vehicle's frame
behind the spare tire mount.
The harness requires the installation
of a trailer connector, which is
available through your dealer.
If towing a light‐duty trailer with
a standard four‐way round pin
connector, an adapter is available
from your dealer.
Page 477 of 594

Black plate (53,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-53
FusesUsage
51 Heated Mirrors
52 SEO B1 Upfitter
Usage (Battery)
53 Cigarette Lighter,
Auxiliary Power
Outlet
54 SEO Upfitter
Usage
55 Climate Controls
(Ignition)
56 Engine Control
Module, Secondary
Fuel Pump
(Ignition)
J-Case Fuses Usage
57 Cooling Fan 1
58 Not Used
59 Heavy Duty
Antilock Brake
System J-Case
Fuses Usage
60 Cooling Fan 2
61 Antilock Brake
System 1
62 Starter
63 Stud 2
(Trailer Brakes)
64 Left Bussed
Electrical Center 1
65 Not Used
66 Heated Windshield
Washer System
67 Transfer Case
68 Stud 1 (Trailer
Connector
Battery Power)
(Optional - 40A
Fuse Required)
69 Mid-Bussed
Electrical Center 1
70 Climate Control
Blower J-Case
Fuses Usage
71 Not Used
72 Left Bussed
Electrical Center 2
Relays Usage
FAN HI Cooling Fan High
Speed
FAN LO Cooling Fan Low
Speed
FAN CNTRL Cooling Fan
Control
HDLP
LO/HID Low-Beam
Headlamp
FOG LAMP Front Fog Lamps
A/C
CMPRSR Air Conditioning
Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL PMP Fuel Pump
PRK LAMP Parking Lamps
Page 478 of 594
Black plate (54,1)GMC Sierra Owner Manual - 2011
10-54 Vehicle Care
RelaysUsage
REAR
DEFOG Rear Defogger
RUN/CRNK Switched Power
Instrument Panel Fuse
Block
The instrument panel fuse block
access door is located on the driver
side edge of the instrument panel.
Pull off the cover to access the fuse
block.
The vehicle may not be equipped
with all of the fuses, relays, and
features shown. Fuses Usage
1 Rear Seats
2 Rear Accessory
Power Outlet Fuses Usage
3 Steering Wheel
Controls Backlight
4 Driver Door Module
5 Dome Lamps, Driver
Side Turn Signal