2009 HUMMER H3 cooling

Electric Power
Management
The vehicle has Electric Power
Management (EPM) that estimates
the battery’s temperature and
state of charge. It then adjusts the
voltage for best performance
and extended life of the battery.
When the battery’s state of charge
is low, the voltage is raised
slightly to quickly bring the charge
back up. When the state of charge is
high, the voltage is lowered
slightly to prevent overcharging. If
the vehicle has a voltmeter gage or
a voltage display on the Driver
Information Center (DIC), you may
see the voltage move up or
down. This is normal. If there is a
problem, an alert will be displayed.
The battery can be discharged
at idle if the electrical loads are very
high. This is true for all vehicles.
This is because the generator
(alternator) may not be spinning fastenough at idle to produce all the
power that is needed for very high
electrical loads.
A high electrical load occurs when
several of the following are on, such
as: headlamps, high beams, fog
lamps, rear window defogger,
climate control fan at high speed,
heated seats, engine cooling fans,
trailer loads, and loads plugged into
accessory power outlets.
EPM works to prevent excessive
discharge of the battery. It does this
by balancing the generator’s
output and the vehicle’s electrical
needs. It can increase engine
idle speed to generate more power,
whenever needed. It can temporarily
reduce the power demands of
some accessories.
Normally, these actions occur in
steps or levels, without being
noticeable. In rare cases at the
highest levels of corrective action,this action may be noticeable to the
driver. If so, a Driver Information
Center (DIC) message might be
displayed, such as BATTERY
SAVER ACTIVE, BATTERY
VOLTAGE LOW, or LOW BATTERY.
If this message is displayed, it is
recommended that the driver reduce
the electrical loads as much as
possible. SeeDIC Warnings and
Messages on page 3-37.
Battery Run-Down
Protection
This feature shuts off the dome
lamp if it is left on for more
than 20 minutes when the ignition is
in LOCK/OFF. This helps to
prevent the battery from being
drained.
Instrument Panel 3-17

Climate Controls
Climate Control System
The heating, cooling, and ventilation of the vehicle can be controlled with this
system.
A. Temperature Control
B. Fan Control
C. Air Delivery Mode Control
D. Air Conditioning
E. Recirculation
F. Rear Window Defogger
9(Off):Turn the fan control to
this position to turn the fan off.
Air still enters the vehicle and
increases with vehicle speed
depending on the mode and
temperature settings. Turn on the
recirculation mode to stop this
airow. Temperature Control:
Turn
clockwise or counterclockwise to
increase or decrease the
temperature of the air in the vehicle.
9(Fan Control): Turn clockwise
or counterclockwise to increase
or decrease the fan speed.
Air Delivery Mode Control: Turn
clockwise or counterclockwise
to change the direction of the airow
in the vehicle. The airow can be
set between modes.
To change the current mode, select
one of the following:
H(Vent): Air is directed to the
instrument panel outlets.
\(Bi-Level): Air is directed to the
instrument panel outlets, and the
remaining air to the oor outlets and
the defroster and side window
outlets. Cooler air is directed to the
upper outlets and warmer air to
the oor outlets.
Instrument Panel 3-19

[(Floor):Air is directed to the
oor outlets, side window outlets,
and defroster. Recirculation is
not available in this mode.
/(Floor/Defog):This mode clears
the windows of fog and moisture.
Air is directed to the windshield, side
window, and oor outlets. The
system runs the air conditioning
unless the outside temperature is
near freezing or below. Recirculation
is not available in this mode.
0(Defrost):This mode clears
the windshield of fog or frost
more quickly. Air is directed to the
windshield and side window
outlets. The system runs the air
conditioning system unless
the outside temperature is near or
below freezing. Recirculation is
not available in this mode.
Do not drive the vehicle until all the
windows are clear.
#(Air Conditioning):Press to
turn the air conditioning system on
or off. An indicator light comes
on when the air conditioning
is turned on. This system cools and
dehumidies the air entering the
vehicle.
The air conditioning will not function
if the fan is turned off. If air
conditioning is selected with fan off,
the indicator light ashes three
times and then turns off.
A slight change in engine
performance may occur when the
air conditioning compressor shuts off
and turns on again. This is normal.
The system is designed to make
adjustments to help with fuel
economy while still maintaining the
selected temperature.
The air conditioning system removes
moisture from the air, so a small
amount of water might drip
under the vehicle while idling or
after turning off the engine. This is
normal.@(Recirculation):Press to turn
the recirculation mode on or off. An
indicator light comes on when the
recirculation is on. This mode
recirculates and helps to quickly cool
the air inside the vehicle. It can be
used to prevent outside air and odors
from entering the vehicle.
Recirculation is available in the
bi-level and vent modes. This mode
cannot be selected while in the oor,
oor/defog or defrost modes. If you
try to select the recirculation mode,
the indicator ashes three times
indicating it is not available in that
mode. When the recirculation mode
is turned on, the air conditioning
turns on automatically.
When it is hot enough outside, the
recirculation mode may turn on
automatically to help improve cooling
performance. The indicator light will
be lit to show this mode is active. If
the recirculation button is pressed
while in this mode, the light ashes
three times and stays on to indicate
that recirculation may not be shut off.
3-20 Instrument Panel

Driving in Water
{CAUTION
Driving through rushing water can
be dangerous. Deep water can
sweep your vehicle downstream
and you and your passengers
could drown. If it is only shallow
water, it can still wash away the
ground from under your tires, and
you could lose traction and roll
the vehicle over. Do not drive
through rushing water.
Heavy rain can mean ash ooding,
and ood waters demand extreme
caution.Find out how deep the water is
before driving through it. Do not
try it if it is deep enough to cover
the wheel hubs, axles, or exhaust
pipe — you probably will not get
through. Deep water can damage the
axle and other vehicle parts. The
vehicle is capable of depths up to
20 inches (50 cm). Know how to
judge whether the water is deeper
than this before proceeding into it.
If the water is not too deep, drive
slowly through it. At faster speeds,
water splashes on the ignition
system and the vehicle can stall.
Stalling can also occur if you get the
tailpipe under water. If the tailpipe
is under water, you will never
be able to start the engine. When
going through water, remember that
when the brakes get wet, it might
take longer to stop. SeeDriving
in Rain and on Wet Roads on
page 4-29.
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
chassis, or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the engine and oil coolers
for mud accumulation. Thoroughly
and carefully clean these devices to
allow proper cooling. Check the
body structure, steering, suspension,
wheels, tires, and exhaust system
for damage and check the fuel lines
and cooling system for any
leakage.
The vehicle requires more frequent
service due to off-road use.
Refer to the Maintenance Schedule
for additional information.
Driving Your Vehicle 4-27

Before Leaving on a
Long Trip
To prepare your vehicle for a long
trip, consider having it serviced
by your dealer/retailer before
departing.
Things to check on your own
include:
Windshield Washer Fluid:
Reservoir full? Windows
clean — inside and outside?
Wiper Blades:In good shape?
Fuel, Engine Oil, Other Fluids:All
levels checked?
Lamps:Do they all work and are
lenses clean?
Tires:Are treads good? Are tires
inated to recommended
pressure?
Weather and Maps:Safe to
travel? Have up-to-date maps?
Highway Hypnosis
Always be alert and pay attention
to your surroundings while driving. If
you become tired or sleepy, nd
a safe place to park your vehicle
and rest.
Other driving tips include:
Keep the vehicle well ventilated.
Keep interior temperature cool.
Keep your eyes moving — scan
the road ahead and to the sides.
Check the rearview mirror and
vehicle instruments often.
Hill and Mountain Roads
Driving on steep hills or through
mountains is different than driving
on at or rolling terrain. Tips for
driving in these conditions include:
Keep the vehicle serviced
and in good shape.
Check all uid levels and brakes,
tires, cooling system, and
transmission.
Going down steep or long hills,
shift to a lower gear.
{CAUTION
If you do not shift down, the
brakes could get so hot that they
would not work well. You would
then have poor braking or even
none going down a hill. You could
crash. Shift down to let the engine
assist the brakes on a steep
downhill slope.
4-30 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

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

A. Windshield Washer Fluid
Reservoir. See “Adding Washer
Fluid” underWindshield
Washer Fluid on page 5-30.
B. Engine Coolant Recovery Tank.
SeeEngine Coolant on
page 5-23.
C.Engine Air Cleaner/Filter on
page 5-17.
D. Power Steering Fluid Reservoir.
SeePower Steering Fluid on
page 5-29.
E. Automatic Transmission Fluid
Dipstick (If Equipped). See
“Checking the Fluid Level”
underAutomatic Transmission
Fluid on page 5-18.
F. Engine Oil Fill Cap. See “When
to Add Engine Oil” under
Engine Oil on page 5-13.G. Radiator Pressure Cap.
SeeCooling System on
page 5-22.
H. Remote Negative (−) Terminal
(GND). SeeJump Starting on
page 5-34.
I. Engine Oil Dipstick. See
“Checking Engine Oil” under
Engine Oil on page 5-13.
J. Positive (+) Battery Terminal.
SeeJump Starting on
page 5-34.
K. Brake Fluid Reservoir.
See “Brake Fluid” under
Brakes on page 5-30.
L.Engine Compartment Fuse Block
on page 5-92.
M.Battery on page 5-33.
N. Hydraulic Clutch Fluid Reservoir
(If Equipped). SeeHydraulic
Clutch on page 5-21.
Service and Appearance Care 5-11