2009 HUMMER H3 brake

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.
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.
4-42 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. 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 1,500 lbs (680 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.
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.
4-48 Driving Your Vehicle

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
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 with an automatic
transmission 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. For vehicles with
a manual transmission, it is
better not to use the highest gear.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 altitude on 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. For vehicles with manual
transmissions, let the engine run
while parked, preferably on
level ground, with the transmission
out of gear and the parking
brake applied, for a few minutes
before turning the engine off. If the
overheat warning comes on,
seeEngine Overheating on
page 5-27.
Driving Your Vehicle 4-49

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 for
vehicles with an automatic
transmission, or into gear for
vehicles with a manual
transmission. 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 into P (Park) for vehicles
with an automatic transmission or
into gear for vehicles with a
manual transmission.
5. Release the brake pedal.
Leaving After Parking on
a Hill
The vehicle has a Hill Start Assist
feature, which may be useful
when stopped on a grade. See
Braking on page 4-3for more
information.
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.
4-50 Driving Your Vehicle

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.
Trailer Wiring Harness
Light-Duty Trailer Wiring Package
If the vehicle does not have a
trailer towing package, the chassis
harness will contain the following
blunt cut circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn
Signal
White: Ground
Brown: Tail Lamps
To add a trailer towing wiring
package, have it installed by your
dealer/retailer or a qualied
service center. Also, seeAdd-On
Electrical Equipment on page 5-91
for more information.Heavy-Duty Trailer Wiring
Package
If the vehicle has a trailer towing
package, the rear bumper harness
will have a seven-pin universal
heavy-duty trailer connector
attached to a bracket on the hitch
platform.
Driving Your Vehicle 4-51

The trailer towing harness contains
the following seven 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 charging a remote (non-vehicle)
battery, turn on the headlamps
to boost the vehicle system voltage
to properly charge the battery.Four-Wire Harness Adapter
If towing a light-duty trailer with a
standard four-way, at pin
connector, an adapter is available
from your dealer/retailer.
Hold the adapter with the tab
pointing up.Connect the adapter to the
seven-pin universal heavy-duty
trailer connector attached to
the bracket on the hitch platform.
The ip cap on the vehicle’s harness
locks onto the tab and helps hold
the adapter in place. Plug the
four-way pin connector onto the
adapter.
4-52 Driving Your Vehicle

Trailer Brake Control Wiring
Harness
The trailer brake control wiring
harness is located under the
instrument panel to the right of the
steering column. The wires are
taped to the harness that goes to
the courtesy light under the
instrument panel. The harness has
the following wires:
Red Wire: AUX B+
Black Wire: Ground
Light Blue Wire: Brake Signal
Dark Blue Wire: Trailer Brakes
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 4-42.
Driving Your Vehicle 4-53

Service and
Appearance Care
Service
Service...............................5-3
Accessories and
Modications.....................5-3
California Proposition
65 Warning.......................5-4
California Perchlorate
Materials Requirements.....5-4
Doing Your Own
Service Work....................5-4
Adding Equipment to the
Outside of the Vehicle........5-5
Fuel
Fuel....................................5-5
Gasoline Octane.................5-5
Gasoline Specications.......5-5
California Fuel....................5-5
Additives.............................5-6
Fuels in Foreign
Countries..........................5-7
Filling the Tank...................5-7
Filling a Portable Fuel
Container..........................5-8
Checking Things Under
the Hood
Checking Things Under
the Hood..........................5-9
Hood Release.....................5-9
Engine Compartment
Overview.........................5-10
Engine Oil.........................5-13
Engine Oil Life System.....5-15
Engine Air Cleaner/Filter. . .5-17
Automatic Transmission
Fluid................................5-18
Manual Transmission
Fluid................................5-20
Hydraulic Clutch................5-21
Cooling System.................5-22
Engine Coolant.................5-23
Engine Overheating...........5-27
Engine Fan Noise.............5-28
Power Steering Fluid.........5-29
Windshield Washer Fluid. . .5-30
Brakes..............................5-30
Battery..............................5-33
Jump Starting...................5-34
Rear Axle
Rear Axle.........................5-38
Four-Wheel Drive
Four-Wheel Drive..............5-38
Front Axle
Front Axle.........................5-39
Headlamp Aiming
Headlamp Aiming..............5-39
Bulb Replacement
Bulb Replacement.............5-41
Halogen Bulbs..................5-41
Headlamps........................5-41
Taillamps, Turn Signal,
Stoplamps and Back-up
Lamps (H3)
.....................5-42
Taillamps, Turn Signal,
Stoplamps and Back-up
Lamps (H3T)
...................5-42
License Plate Lamp..........5-43
Replacement Bulbs...........5-43
Service and Appearance Care 5-1