BUICK ENCLAVE 2009 Owner's Manual
Page 261 of 412
VehicleMaximum Trailer Weight *GCWR
Front-Wheel Drive 2,000 lbs (907 kg)7,500 lbs (3 402 kg)
Front-Wheel Drive, V92 Trailer Towing Package 4,500 lbs (2 041 kg) 9,500 lbs (4 309 kg)
All-Wheel Drive 2,000 lbs (907 kg)7,700 lbs (3 493 kg)
All-Wheel Drive, V92 Trailer Towing Package 4,500 lbs (2 041 kg)9,700 lbs (4 400 kg)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for the vehicle should not be
exceeded.
Ask your dealer/retailer for our
trailering information or advice, or
write us at our Customer Assistance
Offices. See Customer Assistance
Offices on page 7-4 for more
information.
Weight of the Trailer Tongue
The tongue load (A) of any trailer is
an important weight to measure
because it affects the total gross
weight of the vehicle. The Gross
Vehicle Weight (GVW) includes the
curb weight of the vehicle, any
cargo carried in it, and the people
who will be riding in the vehicle.
If there are a lot of options,
equipment, passengers or cargo in the vehicle, it will reduce the tongue
weight the vehicle can carry,
which will also reduce the trailer
weight the vehicle can tow. If towing
a trailer, the tongue load must be
added to the GVW because
the vehicle will be carrying that
weight, too. See
Loading the Vehicle
on page 4-16 for more information
about the vehicle’s maximum
load capacity.
If a weight-carrying hitch or a
weight-distributing hitch is being
used, the trailer tongue (A) should
weigh 10-15 percent of the total
loaded trailer weight (B).
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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).
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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. 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 weighs3,100 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
in ated to the upper limit for cold
tires. These numbers can be found
on the Certi cation/Tire label.
SeeLoading the Vehicle onpage 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. See
Engine Exhaust on page 2-30.
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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.
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.
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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.
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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 Trailer later in thissection. 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 bene t 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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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.
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Trailer Wiring Harness
The vehicle is equipped with the
following wiring harness 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
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 quali ed
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 5-20.
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