2009 CHEVROLET SUBURBAN Electrical

SERVICE AIR BAG
This message displays if there is a problem with the
airbag system. Have your dealer/retailer inspect
the system for problems. SeeAirbag Readiness Light
on page 3-37andAirbag System on page 1-81for more
information.
SERVICE BATTERY CHARGING
SYSTEM
On some vehicles, this message displays if there is a
problem with the battery charging system. Under certain
conditions, the charging system light may also turn
on in the instrument panel cluster. SeeCharging System
Light on page 3-39. Driving with this problem could
drain the battery. Turn off all unnecessary accessories.
Have the electrical system checked as soon as
possible. See your dealer/retailer.
SERVICE BRAKE SYSTEM
This message displays along with the brake system
warning light if there is a problem with the brake system.
SeeBrake System Warning Light on page 3-40. If this
message appears, stop as soon as possible and turn off
the vehicle. Restart the vehicle and check for the
message on the DIC display. If the message is still
displayed or appears again when you begin driving, the
brake system needs service as soon as possible.
See your dealer/retailer.
SERVICE BRAKES SOON
This message displays if there is a problem with the
brake system. If this message appears, stop as soon as
possible and turn off the vehicle. Restart the vehicle
and check for the message on the DIC display. If
the message is still displayed or appears again when
you begin driving, the brake system needs service. See
your dealer/retailer.
SERVICE PARK ASSIST
If your vehicle has the Ultrasonic Rear Parking Assist
(URPA) system, this message displays if there is a
problem with the URPA system. Do not use this system
to help you park. SeeUltrasonic Rear Parking Assist
(URPA) on page 2-56for more information. See
your dealer/retailer for service.
SERVICE SIDE BLIND ZONE ALERT
SYSTEM
If your vehicle has the Side Blind Zone Alert (SBZA)
system and this message displays, both SBZA displays
will remain on indicating there is a problem with the
SBZA system. If these displays remain on after
continued driving, the system needs service. See your
dealer/retailer. SeeSide Blind Zone Alert (SBZA)
on page 2-58for more information.
3-69

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.
4-60

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
4-64

Other ITBC Related DIC Messages
In addition to displaying TRAILER GAIN and TRAILER
OUTPUT through the DIC, trailer connection and
ITBC system status is displayed in the DIC.
TRAILER CONNECTED – This message will be
briey displayed when a trailer with electric brakes
is rst connected to the vehicle. This message will
automatically turn off in about ten seconds. The driver
can also acknowledge this message before it
automatically turns off.
CHECK TRAILER WIRING – This message will be
displayed if:
1. The ITBC system rst determines connection to
a trailer with electric brakes and then the trailer
harness becomes disconnected from the vehicle.
If the disconnect occurs while the vehicle is
stationary, this message will automatically turn
off in about thirty seconds. This message will also
turn off if the driver acknowledges this message
off or if the trailer harness is re-connected.
If the disconnect occurs while the vehicle is moving,
this message will continue until the ignition is turned
off. This message will also turn off if the driver
acknowledges this message off or if the trailer
harness is re-connected.2. There is an electrical fault in the wiring to the
electric trailer brakes. This message will continue
as long as there is an electrical fault in the trailer
wiring. This message will also turn off if the driver
acknowledges this message off.
To determine if the electrical fault is on the vehicle side
or trailer side of the trailer wiring harness connection,
do the following:
1. Disconnect the trailer wiring harness from the
vehicle.
2. Turn the ignition OFF.
3. Wait ten seconds, then turn the ignition back
to RUN.
4. If the CHECK TRAILER WIRING message
re-appears, the electrical fault is on the vehicle side.
If the CHECK TRAILER WIRING message only
re-appears when connecting the trailer wiring
harness to the vehicle, the electrical fault is on
the trailer side.
4-65

Towing a trailer requires a certain amount of
experience. Get to know the rig before setting out
for the open road. Get acquainted with the feel of
handling and braking with the added weight of the
trailer. And always keep in mind that the vehicle you
are driving is now longer and not as responsive as the
vehicle is by itself.
Before starting, check all trailer hitch parts and
attachments, safety chains, electrical connectors,
lamps, tires and mirror adjustments. If the trailer has
electric brakes, start the vehicle and trailer moving
and then apply the trailer brake controller by hand
to be sure the brakes are working. This checks
the electrical connection at the same time.
During the trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer brakes
are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving the vehicle without a trailer.
This can help to avoid situations that require heavy
braking and sudden turns.
Passing
More passing distance is needed when towing a trailer.
Because the rig is longer, it is necessary to go much
farther beyond the passed vehicle before returning to
the lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, move that hand
to the left. To move the trailer to the right, move your
hand to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with
the vehicle. The vehicle could be damaged. Avoid
making very sharp turns while trailering.
When turning with a trailer, make wider turns than
normal. Do this so the trailer will not strike soft
shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance.
4-67

Leaving After Parking on a Hill
1. Apply and hold the brake pedal while you:
Start the engine
Shift into a gear
Release the parking brake
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling
a trailer. See this manual’s Maintenance Schedule or
Index for more information. Things that are especially
important in trailer operation are automatic transmission
uid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect
these before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The vehicle is equipped with the following wiring
harnesses for towing a trailer.
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to the
vehicle’s frame. The harness connector can be plugged
into a seven-pin universal heavy-duty trailer connector
available through your dealer/retailer.
The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed*
Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a qualied service center.
4-70

Heavy-Duty Trailer Wiring Harness
Package
The vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal
trailer connector is attached to a bracket on the hitch
platform.The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed*
Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your
dealer/retailer or a qualied service center.
If charging a remote (non-vehicle) battery, press the
Tow/Haul mode button, if equipped, located at the end of
the shift lever. This will boost the vehicle system voltage
and properly charge the battery. If the trailer is too light
for Tow/Haul mode, or the vehicle is not equipped with
Tow/Haul, turn on the headlamps as a second way to
boost the vehicle system and charge the battery.
4-71

Tire Pressure Monitor Operation.....................5-73
Tire Inspection and Rotation...........................5-76
When It Is Time for New Tires.......................5-77
Buying New Tires.........................................5-78
Different Size Tires and Wheels......................5-80
Uniform Tire Quality Grading..........................5-81
Wheel Alignment and Tire Balance..................5-82
Wheel Replacement......................................5-82
Tire Chains..................................................5-84
If a Tire Goes Flat........................................5-85
Changing a Flat Tire.....................................5-86
Removing the Spare Tire and Tools................5-87
Removing the Flat Tire and Installing the
Spare Tire................................................5-92
Secondary Latch System...............................5-99
Storing a Flat or Spare Tire and Tools...........5-102
Spare Tire.................................................5-106
Appearance Care..........................................5-106
Interior Cleaning.........................................5-106
Fabric/Carpet..............................................5-108
Leather......................................................5-108
Instrument Panel, Vinyl, and Other Plastic
Surfaces.................................................5-109
Care of Safety Belts....................................5-109
Weatherstrips.............................................5-109Washing Your Vehicle..................................5-110
Cleaning Exterior Lamps/Lenses....................5-110
Finish Care................................................5-110
Windshield, Backglass, and Wiper Blades.......5-111
Aluminum or Chrome-Plated Wheels
and Trim................................................5-112
Tires.........................................................5-112
Sheet Metal Damage...................................5-113
Finish Damage...........................................5-113
Underbody Maintenance...............................5-113
Chemical Paint Spotting..............................
.5-113
Vehicle Identication.....................................5-114
Vehicle Identication Number (VIN)................5-114
Service Parts Identication Label...................5-114
Electrical System..........................................5-114
Add-On Electrical Equipment.........................5-114
Windshield Wiper Fuses...............................5-115
Power Windows and Other Power Options......5-115
Fuses and Circuit Breakers..........................5-115
Instrument Panel Fuse Block........................5-116
Center Instrument Panel Fuse Block..............5-118
Underhood Fuse Block................................5-119
Capacities and Specications........................5-122
Section 5 Service and Appearance Care
5-2