2010 HUMMER H3 engine

10-24 Vehicle Care
Engine Fan
This vehicle has a clutched engine
cooling fan. When the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the clutch is not engaged. This
improves fuel economy and reduces
fan noise. Under heavy vehicle
loading, trailer towing and/or high
outside temperatures, the fan speed
increases when the clutch engages.
So you may hear an increase in fan
noise. This is normal and should not
be mistaken as the transmission
slipping or making extra shifts.
It is merely the cooling system
functioning properly. The fan will
slow down when additional cooling
is not required and the clutch
disengages.
You may also hear this fan noise
when you start the engine. It will go
away as the fan clutch disengages.
Power Steering Fluid
SeeEngine Compartment Overviewon page 10‑6for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless a
leak in the system is suspected or
an unusual noise is heard. A fluid
loss in this system could indicate a
problem. Have the system inspected
and repaired.
How to Check Power Steering
Fluid
1. Turn the key off and let the
engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Then remove the cap again and look at the fluid level on the
dipstick.
The level should be between the
ADD and FULL marks. If necessary,
add only enough fluid to bring the
level up to the proper range.

Vehicle Care 10-25
What to Use
To determine what kind of fluid to
use, seeRecommended Fluids and
Lubricants
on page 11‑8. Always
use the proper fluid.
Notice: Use of the incorrect fluid
may damage the vehicle and the
damages may not be covered by
the vehicle's warranty. Always
use the correct fluid listed in
Recommended Fluids and
Lubricants on page 11‑8.
Washer Fluid
What to Use
When windshield washer fluid
is needed, be sure to read the
manufacturer's instructions before
use. If operating the vehicle in an
area where the temperature may fall
below freezing, use a fluid that has
sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the washer
symbol on it. Add washer fluid
until the tank is full. See Engine
Compartment Overview
on
page 10‑6for reservoir location.
Notice:
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage the
washer fluid tank and other
parts of the washer system.
Also, water does not clean as
well as washer fluid.
.Fill the washer fluid tank
only three-quarters full
when it is very cold. This
allows for fluid expansion if
freezing occurs, which could
damage the tank if it is
completely full.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
vehicle's windshield washer
system and paint.

Vehicle Care 10-27
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid as
indicated on the reservoir cap. See
Engine Compartment Overview
on
page 10‑6for the location of the
reservoir. There are only two reasons why the
brake fluid level in the reservoir
might go down:
.The brake fluid level goes down
because of normal brake lining
wear. When new linings are
installed, the fluid level goes
back up.
.A fluid leak in the brake
hydraulic system can also cause
a low fluid level. Have the brake
hydraulic system fixed, since a
leak means that sooner or later
the brakes will not work well.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings
are worn, there will be too much
fluid when new brake linings are
installed. Add or remove brake fluid,
as necessary, only when work is
done on the brake hydraulic system.
{WARNING
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
Add brake fluid only when work is
done on the brake hydraulic
system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light on page 5‑14.

10-28 Vehicle Care
What to Add
Use only new DOT 3 brake fluid
from a sealed container. See
Recommended Fluids and
Lubricants on page 11‑8.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it. This
helps keep dirt from entering the
reservoir.
{WARNING
With the wrong kind of fluid in
the brake hydraulic system, the
brakes might not work well. This
could cause a crash. Always use
the proper brake fluid.Notice:
.Using the wrong fluid
can badly damage brake
hydraulic system parts. For
example, just a few drops of
mineral-based oil, such as
engine oil, in the brake
hydraulic system can
damage brake hydraulic
system parts so badly that
they will have to be replaced.
Do not let someone put in
the wrong kind of fluid.
.If brake fluid is spilled
on the vehicle's painted
surfaces, the paint finish can
be damaged. Be careful not
to spill brake fluid on the
vehicle. If you do, wash it off
immediately.
Battery
Refer to the replacement number
shown on the original battery label
when a new battery is needed. See
Engine Compartment Overview
on
page 10‑6for battery location.
{DANGER
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California to
cause cancer and reproductive
harm. Wash hands after handling.

10-30 Vehicle Care
Starter Switch Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle.
2. Firmly apply both the parking brake and the regular brake.
See Parking Brake
on
page 9‑51.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts. 3. For automatic transmission
vehicles, try to start the engine
in each gear. The vehicle
should start only in P (Park) or
N (Neutral). If the vehicle starts
in any other position, contact
your dealer for service.
For manual transmission
vehicles, put the shift lever in
Neutral, push the clutch pedal
down halfway, and try to start
the engine. The vehicle should
start only when the clutch pedal
is pushed down all the way to
the floor. If the vehicle starts
when the clutch pedal is not
pushed all the way down,
contact your dealer for service.
Automatic Transmission
Shift Lock Control
System Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should be
parked on a level surface.
2. Firmly apply the parking brake. See Parking Brake
on
page 9‑51.
Be ready to apply the regular
brake immediately if the vehicle
begins to move.

Vehicle Care 10-31
3. With the engine off, turn theignition to ON/RUN, but do
not start the engine. Without
applying the regular brake, try
to move the shift lever out of
P (Park) with normal effort. If the
shift lever moves out of P (Park),
contact your dealer for service.
Ignition Transmission
Lock Check
While parked, and with the parking
brake set, try to turn the ignition to
LOCK/OFF in each shift lever
position.
.For automatic transmission
vehicles, the ignition should turn
to LOCK/OFF only when the
shift lever is in P (Park). The
ignition key should come out
only in LOCK/OFF.
.For manual transmission
vehicles, the ignition key should
come out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{WARNING
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move. Park on a fairly steep hill, with the
vehicle facing downhill. Keeping
your foot on the regular brake, set
the parking brake.
.To check the parking brake's
holding ability: With the engine
running and the transmission in
N (Neutral), slowly remove foot
pressure from the regular brake
pedal. Do this until the vehicle is
held by the parking brake only.
.To check the P (Park)
mechanism's holding ability:
With the engine running, shift
to P (Park). Then release the
parking brake followed by the
regular brake.
Contact your dealer if service is
required.

Vehicle Care 10-39
Fuses and Circuit
Breakers
The wiring circuits in your vehicle
are protected from short circuits by
a combination of fuses and circuit
breakers. This greatly reduces the
chance of fires caused by electrical
problems.
Look at the silver-colored band
inside the fuse. If the band is broken
or melted, replace the fuse. Be sure
you replace a bad fuse with a new
one of the identical size and rating.
If you ever have a problem on the
road and do not have a spare fuse,
you can borrow one that has the
same amperage. Just pick some
feature of your vehicle that you can
get along without—like the radio
or cigarette lighter —and use its
fuse, if it is the correct amperage.
Replace it as soon as you can.
Engine Compartment
Fuse Block
The engine compartment fuse
block is located on the driver side
of the engine compartment. See
Engine Compartment Overview
on
page 10‑6for more information on
location.
To remove the cover, push in on the
tabs at the ends of the cover and
lift. To reinstall the cover, line up the
tabs and push down on the cover
until the tabs clicks into place.
Notice: Spilling liquid on any
electrical components on the
vehicle may damage it. Always
keep the covers on any electrical
component.

10-46 Vehicle Care
(B) TPC Spec (Tire
Performance Criteria
Specification)
:Original
equipment tires designed to
GM's specific tire performance
criteria have a TPC specification
code molded onto the sidewall.
GM's TPC specifications meet
or exceed all federal safety
guidelines.
(C) Dual Tire Maximum Load
:
Maximum load that can be
carried and the maximum
pressure needed to support
that load when used in a
dual configuration. For
information on recommended
tire pressure see Tire Pressure
on page 10‑51andVehicle Load
Limits
on page 9‑27.
(D) DOT (Department of
Transportation)
:The
Department of Transportation
(DOT) code indicates that the tire is in compliance with
the U.S. Department of
Transportation Motor
Vehicle Safety Standards.
(E) Tire Identification Number
(TIN)
:The letters and numbers
following DOT code are the Tire
Identification Number (TIN). The
TIN shows the manufacturer and
plant code, tire size, and date
the tire was manufactured.
The TIN is molded onto both
sides of the tire, although only
one side may have the date of
manufacture.
(F) Tire Ply Material
:The type
of cord and number of plies in
the sidewall and under the tread.
(G) Single Tire Maximum
Load
:Maximum load that can
be carried and the maximum
pressure needed to support that
load when used as a single. For
information on recommended tire pressure see
Tire Pressure
on page 10‑51andVehicle Load
Limits
on page 9‑27.
Tire Designations
Tire Size
The following examples show
the different parts of a tire size.
Passenger (P‐Metric) Tire
(A) Passenger (P‐Metric) Tire:
The United States version of a
metric tire sizing system. The
letter P as the first character in
the tire size means a passenger
vehicle tire engineered to
standards set by the U.S. Tire
and Rim Association.