2008 GMC SIERRA panel

The traction control disable
button is located on the
instrument panel below the
climate controls.
The traction control part of StabiliTrak
®can be turned
off by pressing and releasing the StabiliTrak®button
if both systems (traction control and StabiliTrak®) were
previously on. To disable both traction control and
StabiliTrak
®, press and hold the button for ve seconds.
Traction control and StabiliTrak
®can be turned on by
pressing and releasing the StabiliTrak®button if
not automatically shut off for any other reason.
When the TCS or StabiliTrak
®system is turned off,
the StabiliTrak®light and the appropriate TCS off
or StabiliTrak®off message will be displayed on the DIC
to warn the driver. Your vehicle will still have
brake-traction control when traction control is off, but will
not be able to use the engine speed management
system. See “Traction Control Operation” next for more
information.
When the traction control system has been turned off,
you may still hear system noises as a result of the
brake-traction control coming on.It is recommended to leave the system on for normal
driving conditions, but it may be necessary to turn the
system off if your vehicle is stuck in sand, mud, ice or
snow, and you want to “rock” your vehicle to attempt to
free it. It may also be necessary to turn off the system
when driving in extreme off-road conditions where high
wheel spin is required. SeeIf Your Vehicle is Stuck in
Sand, Mud, Ice, or Snow on page 4-34.
When the transfer case is in 4LO, the stability system is
automatically disabled, the StabiliTrak
®light will come
on and the STABILITRAK OFF message will appear on
the DIC. Both traction control and StabiliTrak
®are
automatically disabled in this condition.
Traction Control Operation
The traction control system is part of the StabiliTrak®
system. Traction control limits wheel spin by reducing
engine power to the wheels (engine speed
management) and by applying brakes to each individual
wheel (brake-traction control) as necessary.
The traction control system is enabled automatically
when you start your vehicle. It will activate and the
StabiliTrak
®light will ash if it senses that any of the
wheels are spinning or beginning to lose traction while
driving. If you turn off traction control, only the
brake-traction control portion of traction control will
work. The engine speed management will be disabled.
4-7

Integrated Trailer Brake Control
System
Your vehicle may have an
Integrated Trailer Brake
Control (ITBC) system for
electric trailer brakes.
This symbol is located on the Trailer Brake Control
Panel on vehicles with an Integrated Trailer Brake
Control System. The power output to the trailer brakes
is based on the amount of brake pressure being
applied by your vehicle’s brake system. This available
power output to the trailer brakes can be adjusted
to a wide range of trailering situations.The ITBC system is integrated with your vehicle’s brake,
anti-lock brake and StabiliTrak
®(if equipped) systems.
In trailering conditions that cause your vehicle’s anti-lock
brake or StabiliTrak
®systems to activate, power sent
to the trailer’s brakes will be automatically adjusted
to minimize trailer wheel lock-up. This does not imply
that your trailer has the StabiliTrak
®system.
If your vehicle’s brake, anti-lock brake or StabiliTrak
®
systems are not functioning properly, your ITBC system
may not be fully functional or may not function at all.
Make sure all of these systems are fully operational to
ensure full functionality of the ITBC system.
The ITBC system is powered through your vehicle’s
electrical system. Turning the ignition off will also turn off
the ITBC system. The ITBC system is fully functional
only when the ignition is in ON or in RUN.
The ITBC system can only be used with trailers with
electric brakes.
4-78

Trailer Brake Control Panel
A. Manual Trailer Brake Apply Lever
B. Trailer Gain Adjustment ButtonsThe ITBC system has a control panel located on the
instrument panel to the left of the steering column. See
Instrument Panel Overview (Base/Uplevel version)
on page 3-4orInstrument Panel Overview (Premium
version) on page 3-6for more information on location.
The control panel allows you to adjust the amount
of output, referred to as trailer gain, available to
the electric trailer brakes and allows you to manually
apply the trailer brakes. The Trailer Brake Control Panel
is used along with the Trailer Brake Display Page on
the DIC to adjust and display power output to the trailer
brakes.
Trailer Brake DIC Display Page
The ITBC system displays messages into the vehicle’s
Driver Information Center (DIC). SeeDIC Warnings
and Messages on page 3-63for more information.
4-80

TRAILER GAIN – This setting is displayed anytime the
Trailer Brake Display Page is active. This setting
can be adjusted from 0.0 to 10.0 with either a trailer
connected or disconnected. To adjust the Trailer Gain,
press one of the Trailer Gain adjustment buttons
located on the Trailer Brake Control Panel. Press and
hold a gain button to cause the Trailer Gain to
continuously adjust. To turn the output to the trailer off,
adjust the Trailer Gain setting to 0.0 (zero).
0.0 (zero) gain is the factory default setting. To properly
adjust trailer gain, see the Trailer Gain Adjustment
Procedure later in this section.
TRAILER OUTPUT – This is displayed any time a trailer
with electric brakes is connected. Output to the electric
brakes is based on the amount of vehicle braking
present and relative to the Trailer Gain setting. Output is
displayed from 0 to 10 bars for each gain setting.
The Trailer Output will indicate “------“ontheTrailer
Brake Display Page whenever the following occur:
No trailer is connected.
A trailer without electric brakes is connected (no
DIC message is displayed).
A trailer with electric brakes has become
disconnected (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault present in the wiring to the electric
trailer brakes (a CHECK TRAILER WIRING
message will also be displayed on the DIC).
There is a fault in the ITBC system (a SERVICE
TRAILER BRAKE SYSTEM message will also
be displayed in the DIC).
Manual Trailer Brake Apply
The Manual Trailer Brake Apply Lever is located on the
Trailer Brake Control Panel and is used to apply the
trailer’s electric brakes independent of your vehicle’s
brakes. This lever is used in the Trailer Gain Adjustment
Procedure to properly adjust the power output to the
trailer brakes. Sliding the lever to the left will apply only
the trailer brakes. The power output to the trailer is
indicated in the Trailer Brake Display Page in the DIC.
If your vehicle’s service brakes are applied while
using the Manual Trailer Brake Apply Lever, the trailer
output power will be the greater of the two.
The trailer and the vehicle’s brake lamps will come on
when either vehicle braking or manual trailer brakes
are applied.
4-82

Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specic trailering
condition and must be adjusted any time vehicle loading,
trailer loading or road surface conditions change.
Setting the Trailer Gain properly is needed for the best
trailer stopping performance. A trailer that is
over-gained may result in locked trailer brakes. A trailer
that is under-gained may result in not enough trailer
braking. Both of these conditions may result in poorer
stopping and stability of the vehicle and trailer.
Use the following procedure to correctly adjust Trailer
Gain for each towing condition:
1. Make sure the trailer brakes are in proper working
condition.
2. Connect a properly loaded trailer to the vehicle and
make all necessary mechanical and electrical
connections. SeeLoading Your Vehicle on
page 4-36for more information.3. After the electrical connection is made to a trailer
equipped with electric brakes:A TRAILER CONNECTED message will be
briey displayed on the DIC display.
The Trailer Brake Display Page will appear on
the DIC showing TRAILER GAIN and TRAILER
OUTPUT.
In the Trailer Output display on the DIC,
“------”will disappear if there is no error
present. Connecting a trailer without electric
brakes will not clear the six dashed lines.
4. Adjust the Trailer Gain by using the gain adjustment
(+ /−) buttons on the Trailer Brake Control Panel.
5. Drive the vehicle with the trailer attached on a
level road surface representative of the towing
condition and free of traffic at about 20 to 25 mph
(32 to 40 km/h) and fully apply the Manual
Trailer Brake Apply lever.
Adjusting trailer gain at speeds lower than
20 to 25 mph (32 to 40 km/h) may result in an
incorrect gain setting.
4-83

Turn Signals When Towing a Trailer
The arrows on your instrument panel will ash whenever
you signal a turn or lane change. Properly hooked up,
the trailer lamps will also ash, telling other drivers
you’re about to turn, change lanes or stop.
When towing a trailer, the arrows on your instrument
panel will ash for turns even if the bulbs on the trailer
are burned out. Thus, you may think drivers behind
you are seeing your signal when they are not. It’s
important to check occasionally to be sure the trailer
bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforeyou start
down a long or steep downgrade. If you don’t shift
down, you might have to use your brakes so much that
they would get hot and no longer work well.You can tow in DRIVE (D). You may want to shift the
transmission to lower gear selection if the transmission
shifts too often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode if the
transmission shifts too often. SeeTow/Haul Mode
Light on page 3-53.
When towing at high elevation on steep uphill grades,
consider the following: Engine coolant at higher
elevations will boil at a lower temperature than at or
near sea level. If you turn your engine off immediately
after towing at high elevation on steep uphill grades,
your vehicle may show signs similar to engine
overheating. To avoid this, let the engine run while
parked, preferably on level ground, with the transmission
in PARK (P) at least ve minutes before turning the
engine off. If you do get the overheat warning, see
Engine Overheating on page 5-30.
4-88

Electric Brake Control Wiring
Provisions
These wiring provisions are included with your vehicle
as part of the trailer wiring package. These provisions
are for an electric brake controller. The instrument panel
contains blunt cut wires near the data link connector
for the trailer brake controller. The harness contains the
following wires:
Dark Blue: Brake Signal to Trailer Connector
Red/Black: Battery
Light Blue/White: Brake Switch
White: Ground
It should be installed by your dealer or a qualied
service center.
If your vehicle is equipped with an ITBC, the blunt cuts
exist, but are not connected further in the harness. If
you install an aftermarket trailer brake controller,
the ITBC must be disconnected. Do not power both
ITBC and aftermarket controllers to control the trailer
brakes at the same time.
Auxiliary Battery
The auxiliary battery provision can be used to supply
electrical power to additional equipment that you
may choose to add, such as a slide-in camper. If your
vehicle has this provision, this relay will be located
on the driver’s side of the vehicle, next to the underhood
electrical center.
Be sure to follow the proper installation instructions that
are included with any electrical equipment that you
install.
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.
4-93

Headlamp Aiming...........................................5-56
Bulb Replacement..........................................5-59
Halogen Bulbs..............................................5-59
Headlamps..................................................5-60
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp.............................................5-61
Pickup Box Identication and Fender
Marker Lamps...........................................5-62
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-62
License Plate Lamp......................................5-64
Replacement Bulbs.......................................5-65
Windshield Wiper Blade Replacement..............5-65
Tires..............................................................5-66
Tire Sidewall Labeling...................................5-67
Tire Terminology and Denitions.....................5-71
Ination - Tire Pressure.................................5-74
Dual Tire Operation.......................................5-76
Tire Pressure Monitor System.........................5-76
Tire Pressure Monitor Operation.....................5-78
Tire Inspection and Rotation...........................5-81
When It Is Time for New Tires.......................5-84
Buying New Tires.........................................5-84Different Size Tires and Wheels......................5-86
Uniform Tire Quality Grading..........................5-86
Wheel Alignment and Tire Balance..................5-88
Wheel Replacement......................................5-88
Tire Chains..................................................5-90
If a Tire Goes Flat........................................5-91
Changing a Flat Tire.....................................5-92
Removing the Spare Tire and Tools................5-93
Removing the Flat Tire and Installing the
Spare Tire................................................5-98
Secondary Latch System..............................5-105
Storing a Flat or Spare Tire and Tools...........5-108
Spare Tire.................................................5-112
Appearance Care
..........................................5-112
Interior Cleaning.........................................5-112
Fabric/Carpet..............................................5-114
Leather......................................................5-114
Instrument Panel, Vinyl, and Other Plastic
Surfaces.................................................5-115
Care of Safety Belts....................................5-115
Weatherstrips.............................................5-115
Washing Your Vehicle..................................5-116
Cleaning Exterior Lamps/Lenses....................5-116
Finish Care................................................5-116
Section 5 Service and Appearance Care
5-2