towing CHEVROLET AVALANCHE 2009 2.G Owner's Guide

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
CAUTION: (Continued)
CAUTION: (Continued)
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.
4-56

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 4-34
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
4-60

If either the CHECK TRAILER WIRING or SERVICE
TRAILER BRAKE SYSTEM message is displayed while
driving the vehicle, power is no longer available to
the trailer brakes. When traffic conditions allow, carefully
pull the vehicle over to the side of the road and turn
the ignition off. Check the wiring connection to the trailer
and turn the ignition back on. If either of these
messages continues, either the vehicle or trailer needs
service.
An authorized GM dealer may be able to diagnose
and repair problems with the trailer. However, any
diagnosis and repair of the trailer is not covered under
the vehicle warranty. Please contact your trailer
dealer for assistance with trailer repairs and trailer
warranty information.Driving with a Trailer
{CAUTION:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
Have the exhaust system inspected for leaks
and make necessary repairs before starting a
trip.
Never drive with the liftgate, trunk/hatch, or
rear-most window open.
Fully open the air outlets on or under the
instrument panel.
Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 2-53.
4-62

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.
4-63

Turn Signals When Towing a Trailer
The arrows on the instrument panel ash whenever
signaling a turn or lane change. Properly hooked up, the
trailer lamps also ash, telling other drivers the vehicle
is turning, changing lanes or stopping.
When towing a trailer, the arrows on the instrument
panel ash for turns even if the bulbs on the trailer are
burned out. For this reason you may think other
drivers are seeing the signal when they are not. It is
important to check occasionally to be sure the
trailer bulbs are still working.
Driving On Grades
Reduce speed and shift to a lower gearbeforestarting
down a long or steep downgrade. If the transmission is
not shifted down, the brakes might have to be used so
much that they would get hot and no longer work well.
Vehicles can tow in D (Drive). Shift the transmission to
a lower gear if the transmission shifts too often under
heavy loads and/or hilly conditions.
The tow/haul mode may be used if the transmission
shifts too often. See Tow/Haul Mode earlier in this
section.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If the engine is
turned off immediately after towing at high altitudeon steep uphill grades, the vehicle may show signs
similar to engine overheating. To avoid this, let
the engine run while parked, preferably on level ground,
with the automatic transmission in P (Park) for a
few minutes before turning the engine off. If the overheat
warning comes on, seeEngine Overheating on
page 5-30.
Parking on Hills
{CAUTION:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on a
at surface.
If parking the rig on a hill:
1. Press the brake pedal, but do not shift into P (Park)
yet. Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
4-64

3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking
brake and shift into P (Park).
5. If the vehicle is four-wheel-drive, be sure the
transfer case is in a drive gear and not in
N (Neutral).
6. Release the brake pedal.
{CAUTION:
It can be dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the parking
brake rmly set. The vehicle can roll.
If the engine has been left running, the vehicle can
move suddenly. You or others could be injured. To
be sure the vehicle will not move, even when on
fairly level ground, use the steps that follow.
Always put the shift lever fully in P (Park) with the
parking brake rmly set.
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.
4-65

Trailer Wiring Harness
Heavy-Duty Trailer Wiring Harness
Package
Your vehicle is equipped with the seven-wire trailer
towing harness. This harness with a seven-pin universal
heavy-duty trailer connector is attached to the rear
bumper beam. It is located next to the integrated trailer
hitch.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.
4-66

Electric Brake Control Wiring
Provisions
These wiring provisions are included with the 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/retailer or a
qualied service center.
If the vehicle is equipped with an ITBC, the blunt cuts
exist, but are not connected further in the harness. If an
aftermarket trailer brake controller is installed, the
ITBC must be disconnected. Do not power both ITBC
and aftermarket controllers to control the trailer brakes at
the same time.
Trailer Recommendations
Subtract the hitch loads from the Cargo Weight Rating
(CWR). CWR is the maximum weight of the load
the vehicle can carry. It does not include the weight of
the people inside, but you can gure about 150 lbs.
(68 kg) for each passenger. The total cargo load must
not be more than the vehicles CWR.
Weigh the vehicle with the trailer attached, so the
GVWR or GAWR are not exceeded. If using a
weight-distributing hitch, weigh the vehicle without the
spring bars in place.
The best performance is obtained by correctly spreading
out the weight of the load and choosing the correct
hitch and trailer brakes.
For more information seeTowing a Trailer on page 4-47.
4-67

If No Steam Is Coming From The
Engine Compartment
The ENGINE OVERHEATED STOP ENGINE or the
ENGINE OVERHEATED IDLE ENGINE message, along
with a low coolant condition, can indicate a serious
problem.
If you get an engine overheat warning, but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on page 4-47.
If you get the ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE message
with no sign of steam, try this for a minute or so:
If the overheat warning is displayed with no sign of
steam:
1. Turn the air off.
2. Turn the heater on to the highest temperature and
to the highest fan speed. Open the windows as
necessary.3. In heavy traffic, let the engine idle in N (Neutral)
while stopped. If it is safe to do so, pull off the
road, shift to P (Park) or N (Neutral) and let
the engine idle.
If the temperature overheat gage is no longer in the
overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. If the
warning does not come back on, continue to drive
normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
three minutes while parked. If the warning is still
displayed, turn off the engine until it cools down. Also,
see “Overheated Engine Protection Operating Mode”
later in this section.
5-32

Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
ENGINE POWER IS REDUCED message is displayed,
an overheat protection mode which alternates ring
groups of cylinders helps prevent engine damage. In this
mode, you will notice a loss in power and engine
performance. This operating mode allows the vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any
repair. The engine oil will be severely degraded.
Repair the cause of coolant loss, change the oil and
reset the oil life system. SeeEngine Oil on
page 5-15.
Engine Fan Noise
The vehicle has electric cooling fans. You might hear
the fans spinning at low speed during most everyday
driving. The fans can turn off if no cooling is required.
Under heavy vehicle loading, trailer towing, and/or
high outside temperatures, or if you are operating the
air conditioning system, the fans can change to
high speed and you might hear an increase in fan noise.
This is normal and indicates that the cooling system
is functioning properly. The fans change to low speed
when additional cooling is no longer required.
5-33