2009 GMC ACADIA trailer

After loading the trailer, weigh the
trailer and then the tongue,
separately, to see if the weights are
proper. If they aren’t, adjustments
might be made by moving some
items around in the trailer.
Trailering may also be limited by the
vehicle’s ability to carry tongue
weight. Tongue weight cannot cause
the vehicle to exceed the GVWR
(Gross Vehicle Weight Rating) or the
RGAWR (Rear Gross Axle Weight
Rating). The effect of additional
weight may reduce the trailering
capacity more than the total of the
additional weight.Consider the following example:
A vehicle model base weight
is 5,500 lbs (2 495 kg); 2,800 lbs
(1 270 kg) at the front axle and
2,700 lbs (1 225 kg) at the rear axle.
It has a GVWR of 7,200 lbs
(3 266 kg), a RGAWR of 4,000 lbs
(1 814 kg) and a GCWR (Gross
Combination Weight Rating)
of 14,000 lbs (6 350 kg). The trailer
rating should be:
Expect tongue weight to be at
least 10 percent of trailer weight
(850 lbs (386 kg)) and because
the weight is applied well behind
the rear axle, the effect on the
rear axle is greater than just
the weight itself, as much as
1.5 times as much. The weight
at the rear axle could be 850 lbs
(386 kg) X 1.5 = 1,275 lbs (578 kg).Since the rear axle already weighs
2,700 lbs (1 225 kg), adding
1,275 lbs (578 kg) brings the total to
3,975 lbs (1 803 kg). This is very
close to, but within the limit for
RGAWR as well. The vehicle is set
to trailer up to 8,500 lbs (3 856 kg).
If the vehicle has many options
and there is a front seat passenger
and two rear seat passengers
with some luggage and gear in the
vehicle as well. 300 lbs (136 kg)
could be added to the front
axle weight and 400 lbs (181 kg) to
the rear axle weight. The vehicle
now weighs:
Weight is still below 7,200 lbs
(3 266 kg) and you might think
700 additional pounds (318 kg)
should be subtracted from the
trailering capacity to stay within
GCWR limits.
Driving Your Vehicle 4-27

The maximum trailer would only be
7,800 lbs (3 538 kg). You may
go further and think the tongue
weight should be limited to less
than 1,000 lbs (454 kg) to avoid
exceeding GVWR. But the effect
on the rear axle must still be
considered. Because the rear axle
now weighs 3,100 lbs (1 406 kg),
900 lbs (408 kg) can be put on
the rear axle without exceeding
RGAWR. The effect of tongue
weight is about 1.5 times the
actual weight. Dividing the 900 lbs
(408 kg) by 1.5 leaves only
600 lbs (272 kg) of tongue weight
that can be handled. Since
tongue weight is usually at least
10 percent of total loaded trailer
weight, expect that the largest
trailer the vehicle can properly
handle is 6,000 lbs (2 721 kg).It is important that the vehicle
does not exceed any of its
ratings —GCWR, GVWR, RGAWR,
Maximum Trailer Rating or Tongue
Weight. The only way to be sure it is
not exceeding any of these ratings is
to weigh the vehicle and trailer.
Total Weight on the
Vehicle’s Tires
Be sure the vehicle’s tires are
inated to the upper limit for cold
tires. These numbers can be found
on the Certication/Tire label.
SeeLoading the Vehicle on
page 4-16. Make sure not to go
over the GVW limit for the vehicle,
including the weight of the trailer
tongue.
Hitches
It is important to have the correct
hitch equipment. Crosswinds,
large trucks going by and rough
roads are a few reasons why
the right hitch is needed. Here
are some rules to follow:
The rear bumper on the vehicle
is not intended for hitches. Do
not attach rental hitches or other
bumper-type hitches to it. Use
only a frame-mounted hitch
that does not attach to the
bumper.
Will any holes be made in the
body of the vehicle when the
trailer hitch is installed? If there
are, then be sure to seal the
holes later when the hitch
is removed. If the holes are not
sealed, dirt, water, and deadly
carbon monoxide (CO) from
the exhaust can get into
the vehicle. SeeEngine
Exhaust on page 2-30.
4-28 Driving Your Vehicle

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. Follow the
manufacturer’s recommendation
for attaching safety chains and do
not attach them to the bumper.
Always leave just enough slack
so the rig can turn. Never allow
safety chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 1,000 lbs (450 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.Because the vehicle has antilock
brakes, do not try to tap into
the vehicle’s hydraulic brake system.
If you do, both brake systems will
not work well, or at all.
Driving with a Trailer
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.
Driving Your Vehicle 4-29

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 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 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
Because of the added load of the
trailer, the vehicle’s engine may
overheat on hot days, when going
up a long or steep grade with a
trailer. If the engine coolant
temperature gage indicates
overheating, turn off the air
conditioning to reduce engine load,
pull off the road and stop in a
safe spot. Let the engine run while
parked, preferably on level
ground, with the transmission in
P (Park) for a few minutes before
turning the engine off.
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.
On a long uphill grade, shift down
and reduce the vehicle speed
to around 55 mph (88 km/h) to
reduce the possibility of the engine
and the transmission overheating.
4-30 Driving Your Vehicle

Tow/Haul Mode
Tow/Haul is a feature that assists
when pulling a heavy trailer or
a large or heavy load. The purpose
of the Tow/Haul mode is to:
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.
Increase the charging system
voltage to assist in recharging
a battery installed in a trailer.Press this button located on the
console to turn on and turn off the
Tow/Haul mode.
The Tow/Haul light on the
instrument panel will come on to
indicate that Tow/Haul mode
has been selected.
Tow/Haul may be turned off by
pressing the button again, at which
time the indicator light on the
instrument panel will turn off. The
vehicle will automatically turn
off Tow/Haul every time it is started.
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 Trailerearlier in this 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.
Driving Your Vehicle 4-31

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.
3. When the wheel chocks are in
place, release the brake pedal
until the chocks absorb the load.4. Reapply the brake pedal. Then
apply the parking brake and
shift the transmission into
P (Park).
5. Release the brake pedal.
Leaving After Parking
on a Hill
1. Apply and hold the brake pedal
while you:
start the 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
The vehicle needs service more
often when pulling a trailer.
SeeScheduled Maintenance on
page 6-3for 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 harness for towing
a trailer.
4-32 Driving Your Vehicle

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
Black: Ground
Light Green: Back-up Lamps
Red/Black: Battery Feed
Dark Blue: Trailer Brake*
*The fuse for this circuit is 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 the back-up lamp circuit is not
functional, contact your
dealer/retailer.If a remote (non-vehicle) battery is
being charged, press the Tow/Haul
mode switch located on the center
console near the climate controls.
This will boost the vehicle system
voltage and properly charge the
battery. If the trailer is too light for
Tow/Haul mode, turn on the
headlamps (Non-HID only) as a
second way to boost the vehicle
system and charge the battery.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. SeeEngine Overheating
on page 5-21.
Driving Your Vehicle 4-33

If Steam Is Coming From The
Engine Compartment
{CAUTION
Steam from an overheated engine
can burn you badly, even if you
just open the hood. Stay away
from the engine if you see or hear
steam coming from it. Turn it off
and get everyone away from the
vehicle until it cools down. Wait
until there is no sign of steam or
coolant before you open the hood.
If you keep driving when the
vehicles engine is overheated, the
liquids in it can catch re. You or
others could be badly burned.
Stop the engine if it overheats,
and get out of the vehicle until the
engine is cool.
SeeOverheated Engine
Protection Operating Mode on
page 5-23for information on
driving to a safe place in an
emergency.
If No Steam Is Coming From
The Engine Compartment
If an engine overheat warning is
displayed but no steam can be seen
or heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
Climbs a long hill on a hot day.
Stops after high-speed driving.
Idles for long periods in traffic.
Tows a trailer.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest
temperature and to the highest
fan speed. Open the windows as
necessary.
3. If in a traffic jam, shift to
N (Neutral), otherwise, shift
to the highest gear while
driving—D(Drive) or L (Low).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”
next in this section.
5-22 Service and Appearance Care