HUMMER H2 2009 Owners Manual

Towing a Trailer
{CAUTION:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is
too heavy, the brakes may not work well — or
even at all. The driver and passengers could be
seriously injured. The vehicle may also be
damaged; the resulting repairs would not be
covered by the vehicle warranty. Pull a trailer only
if all the steps in this section have been followed.
Ask your dealer/retailer for advice and information
about towing a trailer with the vehicle.Notice:Pulling a trailer improperly can damage the
vehicle and result in costly repairs not covered
by the vehicle warranty. To pull a trailer correctly,
follow the advice in this section and see your
dealer/retailer for important information about
towing a trailer with the vehicle.
To identify the trailering capacity of the vehicle, read the
information in “Weight of the Trailer” that appears
later in this section.
Trailering is different than just driving the 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.
The following information has 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 pulling a
trailer.
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Pulling A Trailer
Here are some important points:
There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
the rig will be legal, not only where you live but
also where you will 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.
Do not tow a trailer at all during the rst 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
Then, during the rst 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in at
the heavier loads.
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. See
“Tow/Haul Mode” following.Three important considerations have to do with weight:
The weight of the trailer
The weight of the trailer tongue
The weight on the vehicle’s tires
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. For example, speed,
altitude, road grades, outside temperature and how
much the vehicle is used to pull a trailer are all
important. It can depend on any special equipment on
the 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.
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Use the following chart to determine how much the vehicle can weigh, based upon the vehicle model and options.
Engine Axle Ratio Maximum Trailer Weight **GCWR
6.2L V8 (SUV) 3.73 8,200 lbs (3 720 kg) 15,000 lbs (6 804 kg)
6.2L V8 (SUT)* 3.73 8,200 lbs (3 720 kg) 15,000 lbs (6 804 kg)
*Sport utility truck (SUT) models are neither designed nor intended to tow 5th wheel or gooseneck trailers.
**The Gross Combination Weight Rating (GCWR) in 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 7-6for more information.
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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. SeeLoading the Vehicle on page 4-44for more
information about the 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) with a weight distributing
hitch.
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Do not exceed the maximum allowable tongue weight
for the 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.
The spare tire carrier is behind the tailgate. If the hitch
extension is too short, the spare tire may interfere with
trailer coupling or trailer tongue jack operation on some
types of trailers.
After loading the trailer, weigh the trailer and then the
tongue, separately, to see if the weights are proper.
If they are not, adjustments might be made by moving
some items around in the trailer.
Trailering may 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 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 label at the rear edge of the driver’s door or
seeLoading the Vehicle on page 4-44for more
information. Make sure not to go over the GVW limit for
the vehicle, or the GAWR, including the weight of the
trailer tongue. If using a weight distributing hitch,
make sure not to go over the rear axle limit before
applying the weight distribution spring bars.
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.
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Weight-Distributing Hitches and Weight
Carrying Hitches
A:Body to Ground Distance
B:Front of Vehicle
When using a weight-distributing hitch, the hitch must
be adjusted so the distance (A) remains the same both
before and after coupling the trailer to the tow vehicle.If a step-bumper hitch will be used, the bumper could be
damaged in sharp turns. Make sure there is ample room
when turning to avoid contact between the trailer and the
bumper.
If the loaded trailer being pulled 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. Always use a
sway control if the trailer will weigh more than these
limits. Ask a hitch dealer about sway controls.
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. If
the trailer being towed weighs up to the vehicle’s trailer
rating limit, safety chains may be attached to the
attaching point on the hitch platform. Always leave just
enough slack so the rig can turn. Never allow safety
chains to drag on the ground.
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Tow/Haul Mode
Pressing this button at
the end of the shift lever
turns on and off the
tow/haul mode.
This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.
Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. SeeTow/Haul Mode
on page 2-36for more information.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 the 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.
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Trailer Brakes
A loaded trailer that weighs more than 2,000 lbs
(900 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.
Since the vehicle is equipped with StabiliTrak
®, the trailer
brakes cannot tap into the vehicle’s hydraulic brake
system.
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.
CAUTION: (Continued)
CAUTION: (Continued)
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 2-45.
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.
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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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