2009 CHEVROLET SUBURBAN Owners Manual

Weight-Distributing Hitches and Weight
Carrying Hitches
A:Body to Ground Distance
B:Front of Vehicle
When using a weight-distributing hitch, the hitch must
be adjusted so the distance (A) remains the same both
before and after coupling the trailer to the tow vehicle.If a step-bumper hitch will be used, the bumper could be
damaged in sharp turns. Make sure there is ample room
when turning to avoid contact between the trailer and the
bumper.
If the loaded trailer being pulled will weigh more than
5,000 lbs (2 270 kg), be sure to use a properly mounted
weight-distributing hitch and sway control of the proper
size. This equipment is very important for proper vehicle
loading and good handling when driving. Always use a
sway control if the trailer will weigh more than these
limits. Ask a hitch dealer about sway controls.
Safety Chains
Always attach chains between the vehicle and the
trailer. Cross the safety chains under the tongue of the
trailer to help prevent the tongue from contacting the road
if it becomes separated from the hitch. Instructions about
safety chains may be provided by the hitch manufacturer
or by the trailer manufacturer. If the trailer being towed
weighs up to the vehicle’s trailer rating limit, safety chains
may be attached to the attaching point on the hitch
platform. Always leave just enough slack so the rig can
turn. Never allow safety chains to drag on the ground.
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Tow/Haul Mode
Pressing this button at
the end of the shift lever
turns on and off the
tow/haul mode.
This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 2-38for more information.Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75 percent
of the vehicle’s Gross Combined Weight Rating (GCWR).
See “Weight of the Trailer” earlier in the section. Tow/
Haul is most useful under the following driving conditions:
When pulling a heavy trailer or a large or heavy load
through rolling terrain.
When pulling a heavy trailer or a large or heavy load
in stop and go traffic.
When pulling a heavy trailer or a large or heavy load
in busy parking lots where improved low speed
control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benet to the selection of Tow/Haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/Haul is
recommended only when pulling a heavy trailer or a large
or heavy load.
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Trailer Brakes
A loaded trailer that weighs more than 2,000 lbs (900 kg)
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.
Since the vehicle is equipped with StabiliTrak
®, the
trailer brakes cannot tap into the vehicle’s hydraulic
system.
Integrated Trailer Brake Control
System
The 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 the
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 the vehicle’s brake,
anti-lock brake and StabiliTrak (if equipped) systems.
In trailering conditions that cause the 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 the trailer has the StabiliTrak system.
If the vehicle’s brake, anti-lock brake or StabiliTrak
systems are not functioning properly, the 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.
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The ITBC system is powered through the 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.
{CAUTION:
Connecting a trailer that is not compatible with the
ITBC system may result in reduced or complete
loss of trailer braking. There may be an increase in
stopping distance or trailer instability which could
result in personal injury or damage to the vehicle,
trailer, or other property. An aftermarket controller
may be available for use with trailers with surge,
air or electric-over-hydraulic trailer brake systems.
To determine the type of brakes on the trailer and
the availability of controllers, check with your trailer
manufacturer or dealer/retailer.When trailering, make sure of the following:
The ITBC system is used only with trailers that are
equipped with electric brakes.
All applicable local and federal laws and regulations
are followed.
All electrical and mechanical connections to the
trailer are made correctly.
The trailer’s brakes are in proper working condition.
The trailer and vehicle are properly loaded for
the towing condition.
The ITBC system is a factory installed item.
Out-of-factory installation of this system should not
be attempted. GM is not responsible for warranty
or performance of the system resulting from
out-of-factory installation.
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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.
SeeInstrument Panel Overview on page 3-4for more
information on location. The control panel allows
adjustment the amount of output, referred to as trailer
gain, available to the electric trailer brakes and allows
manual application 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.
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Trailer Brake DIC Display Page
The ITBC system displays messages into the vehicle’s
Driver Information Center (DIC). SeeDIC Warnings
and Messages on page 3-64for more information.
The display page indicates Trailer Gain setting, power
output to the electric trailer brakes, trailer connection
and system operational status.
A. Trailer Gain Setting
B. Power Output to Trailer Brakes
C. No trailer with electric brakes connected or fault
presentThe Trailer Brake Display Page can be displayed by
performing any of the following actions:Scrolling through the DIC menu pages using the
odometer trip stem or the DIC Vehicle Information
button (if equipped).
Pressing a Trailer Gain button – If the Trailer Brake
Display Page is not currently displayed, pressing a
Trailer Gain button will rst recall the current Trailer
Gain setting. After the Trailer Brake Display Page
is displayed, each press and release of the gain
buttons will then cause the Trailer Gain setting to
change.
Activating the Manual Trailer Brake Apply lever
Connecting a trailer equipped with electric trailer
brakes
All DIC warning and service messages must rst be
acknowledged by the driver by pressing the odometer trip
stem or the DIC Vehicle Information button (if equipped)
before the Trailer Brake Display Page can be displayed
and Trailer Gain can be adjusted.
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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 the 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 the 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.
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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 the Vehicle on page 4-33
for 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.
6. Adjust the Trailer Gain to just below the point of
trailer wheel lock-up, indicated by trailer wheel
squeal or tire smoke when a trailer wheel locks.
Trailer wheel lock-up may not occur if towing
a heavily loaded trailer. In this case, adjust the
Trailer Gain to the highest allowable setting for
the towing condition.
7. Re-adjust Trailer Gain any time vehicle loading,
trailer loading or road surface conditions change
or if trailer wheel lock-up is noticed at any time
while towing
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