tow CHEVROLET AVALANCHE 2007 2.G Workshop Manual

Towing a Trailer
Do not tow a trailer during break-in. SeeNew
Vehicle Break-In on page 122for more information.
{CAUTION:
If you do not use the correct equipment
and drive properly, you can lose control
when you pull a trailer. For example, if the
trailer is too heavy, the brakes may not
work well — or even at all. You and your
passengers could be seriously injured.
Pull a trailer only if you have followed all
the steps in this section. Ask your dealer
for advice and information about towing
a trailer with your vehicle.Notice:Pulling a trailer improperly can
damage your vehicle and result in costly repairs
not covered by your warranty. To pull a trailer
correctly, follow the advice in this part, and
see your dealer for important information about
towing a trailer with your vehicle.
To identify the trailering capacity of your vehicle,
you should read the information in “Weight of
the Trailer” that appears later in this section.
Trailering is different than just driving your vehicle
by itself. Trailering means changes in handling,
acceleration, braking, durability and fuel economy.
Successful, safe trailering takes correct
equipment, and it has to be used properly.
That’s the reason for this part. In it are many
time-tested, important trailering tips and safety
rules. Many of these are important for your safety
and that of your passengers. So please read
this section carefully before you pull a trailer.
414

If You Do Decide To Pull A Trailer
If you do, here are some important points:
There are many different laws, including speed
limit restrictions, having to do with trailering.
Make sure your rig will be legal, not only
where you live but also where you’ll be driving.
A good source for this information can be
state or provincial police.
Consider using a sway control. See “Hitches”
later in this section.
Don’t tow a trailer at all during the rst 500 miles
(800 km) your new vehicle is driven. Your
engine, axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that
you tow a trailer, don’t drive over 50 mph
(80 km/h) and don’t make starts at full throttle.
This helps your engine and other parts of your
vehicle wear in at the heavier loads.
You can tow in DRIVE (D). You may want
to shift the transmission to THIRD (3) or,
if necessary, a lower gear selection if the
transmission shifts too often (e.g.,
under heavy loads and/or hilly conditions).
See “Tow/Haul Mode” later in this section.Three important considerations have to do
with weight:
the weight of the trailer,
the weight of the trailer tongue
and the weight on your vehicle’s tires.
Tow/Haul Mode
Tow/haul is designed to assist while your vehicle
is pulling a large or heavy load or trailer.
Tow/haul is most useful while pulling such a load
in rolling terrain, in stop-and-go traffic, or when
you need improved low-speed control, such
as when parking. The purpose of the tow/haul
mode is to do the following:
Reduce the frequency and improve the
predictability of transmission shifts when
pulling a heavy trailer or a large or heavy load.
Provide the same solid shift feel when pulling
a heavy trailer or a large or heavy load as
when the vehicle is unloaded.
Improve control of vehicle speed while
requiring less throttle pedal activity when
pulling a heavy trailer or a large or
heavy load.
415

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 Combination
Weight Rating (GCWR). See “Weight of the
Trailer” later in this section.
Press the button at the end of the shift lever to
enable/disable the tow/haul mode.
A light on the instrument
panel will illuminate to
indicate that tow/haul
mode has been
selected.
The vehicle will automatically turn off tow/haul
every time it is started.
Driving with tow/haul activated without a heavy
load or with no trailer will cause reduced fuel
economy and unpleasant engine and transmission
driving characteristics, but will not cause
damage.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.
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how you plan to use your rig. For
example, speed, altitude, road grades, outside
temperature and how much your vehicle is used to
pull a trailer are all important. It can also depend
on any special equipment that you have on
your vehicle, and the amount of tongue weight the
vehicle can carry. See “Weight of the Trailer
Tongue” later in this section for more information.
Maximum trailer weight is calculated assuming
only the driver is in the tow vehicle and it has all
the required trailering equipment. The weight
of additional optional equipment, passengers and
cargo in the tow vehicle must be subtracted
from the maximum trailer weight.
416

Weight of the Trailer Tongue
The tongue load (A) of any trailer is an important
weight to measure because it affects the total
or gross weight of your vehicle. The Gross Vehicle
Weight (GVW) includes the curb weight of the
vehicle, any cargo you may carry in it, and
the people who will be riding in the vehicle. If you
have a lot of options, equipment, passengers
or cargo in your vehicle, it will reduce the tongue
weight your vehicle can carry, which will also
reduce the trailer weight your vehicle can tow.
And if you will tow a trailer, you must add
the tongue load to the GVW because your vehicle
will be carrying that weight, too. SeeLoading
Your Vehicle on page 402for more information
about your vehicle’s maximum load capacity.The trailer tongue weight (A) should be 10 percent
to 15 percent of the total loaded trailer weight (B),
up to a maximum of 600 lbs (272 kg) with a weight
carrying hitch. The trailer tongue weight (A) should
be 10 percent to 15 percent of the total loaded
trailer weight (B), up to a maximum of 1,000 lbs
(454 kg) for the 1500 series and up to a maximum
of 1,500 lbs (680 kg) for the 2500 series with a
weight distributing hitch.
Do not exceed the maximum allowable tongue
weight for your vehicle. Choose the shortest hitch
extension that will position the hitch ball closest
to the vehicle. This will help reduce the effect
of trailer tongue weight on the rear axle.
418

Hitches
It’s important to have the correct hitch equipment.
Crosswinds, large trucks going by and rough roads
are a few reasons why you’ll need the right hitch.
Weight-Distributing Hitches and Weight
Carrying Hitches
When using a weight-distributing hitch, the hitch
must be adjusted so that the distance (A) remains
the same both before and after coupling the
trailer to the tow vehicle.If you’ll be pulling a trailer that, when loaded,
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.
You should always use a sway control if your
trailer will weigh more than these limits. You
can ask a hitch dealer about sway controls.
Safety Chains
You should always attach chains between your
vehicle and your 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. Always
leave just enough slack so you can turn with
your rig. Never allow safety chains to drag
on the ground.
(A) Body-to-Ground Distance (B) Front of Vehicle
421

Trailer Brakes
If your trailer weighs more than 2,000 lbs (900 kg)
loaded, then it needs its own brakes — and
they must be adequate. Be sure to read and
follow the instructions for the trailer brakes so
you’ll be able to install, adjust and maintain
them properly.
Since your vehicle is equipped with the
StabiliTrak
®system, your trailer brake system
cannot tap into the vehicle’s hydraulic brake
system.
Driving with a Trailer
Towing a trailer requires a certain amount of
experience. Before setting out for the open road,
you’ll want to get to know your rig. Acquaint
yourself 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 a good deal longer and not nearly
as responsive as your vehicle is by itself.Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector,
lamps, tires and mirror adjustment. If the trailer
has electric brakes, start your vehicle and
trailer moving and then apply the trailer brake
controller by hand to be sure the brakes are
working. This lets you check your electrical
connection at the same time.
During your 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 your vehicle without
a trailer. This can help you avoid situations
that require heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when
you’re towing a trailer. And, because you’re a
good deal longer, you’ll need to go much farther
beyond the passed vehicle before you can
return to your lane.
422

Backing Up
Hold the bottom of the steering wheel with
one hand. Then, to move the trailer to the left,
just 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. Your vehicle could
be damaged. Avoid making very sharp
turns while trailering.
When you’re turning with a trailer, make wider
turns than normal. Do this so your trailer
won’t strike soft shoulders, curbs, road signs,
trees or other objects. Avoid jerky or sudden
maneuvers. Signal well in advance.
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.
423

Driving On Grades
Reduce speed and shift to a lower gearbefore
you 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 THIRD (3) or, if necessary,
a 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. See “Tow/Haul
Mode” earlier in this section.
When towing at high altitude on steep uphill
grades, consider the following: Engine coolant
at higher altitudes will boil at a lower temperature
than at or near sea level. If you turn your
engine off immediately after towing at high
altitude 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 automatic
transmission in PARK (P) for a few minutes before
turning the engine off. If you do get the overheat
warning, seeEngine Overheating on page 460.
Parking on Hills
{CAUTION:
You really should not park your
vehicle, with a trailer attached, on a hill.
If something goes wrong, your rig could
start to move. People can be injured,
and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
424

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your engine,
shift into a gear, and
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
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission uid (don’t overll), engine
oil, axle lubricant, belts, cooling system and
brake system. Each of these is covered in this
manual, and the Index will help you nd them
quickly. If you’re trailering, it’s a good idea
to review these sections before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
426

Trailer Wiring Harness
Heavy-Duty Trailer Wiring 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 #
** If you are charging a remote (non-vehicle)
battery, press the tow/haul mode button 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, you can turn on the headlamps as a
second way to boost the vehicle system and
charge the battery.
# The fuses for these circuits are installed in the
underhood electrical center, but the wires are
not connected. These circuits should be connected
by your dealer or a qualied service technician.
427