cooling HUMMER H3 2007 Owners Manual

Dome Lamp Override
E(Dome Lamp Override):You can use the
dome override button, located below the exterior
lamps control, to set the dome and footwell
lamps to come on automatically when a door is
opened, or to remain off. To turn the lamps
off, press the button into the in position. With the
button in this position, the dome lamps will
remain off when the doors are open. To return
the lamps to automatic operation, press the
button again and return it to the out position.
With the button in this position, the dome lamps
will come on when you open a door.
Exit Lighting
With exit lighting, the interior lamps will come
on when you remove the key from the ignition.
The lamps will not come on if the dome override
button is pressed in.
Reading Lamps
Your vehicle has reading lamps. Press the button
located next to the lamp to turn them on or off.
These lamps will not come on with the dome lamps.
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 put the charge
back in. When the state of charge is high, the
voltage is lowered slightly to prevent overcharging.
If the vehicle has a voltmeter gage, 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 fast enough 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 loads are on: 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.
168

Ashtray(s) and Cigarette Lighter
Your vehicle may have an ashtray and cigarette
lighter.
Your ashtray is located in your center console
area. The ashtray can be removed for cleaning.
When the ashtray is removed, this area can
also be used as a cupholder.
Notice:If you put papers, pins, or other
ammable items in the ashtray, hot cigarettes
or other smoking materials could ignite
them and possibly damage your vehicle.
Never put ammable items in the ashtray.
To use the lighter, press it in all the way, and let
go. When it’s ready, it will pop back out by itself.
Notice:Holding a cigarette lighter in while it
is heating will not allow the lighter to back
away from the heating element when it is hot.
Damage from overheating may occur to the
lighter or heating element, or a fuse could
be blown. Do not hold a cigarette lighter
in while it is heating.
Climate Controls
Climate Control System
This system controls the heating, cooling, and
ventilation of the vehicle. In-between modes are
available by moving the right control knob between
modes with symbols. The in-between mode will
be a combination of the two modes that the control
is centered between.
Temperature:Turn the left knob on the control
panel to adjust the temperature of the air in
the vehicle. Turn the knob clockwise or
counterclockwise to increase or decrease the
temperature.
170

Driving in Mud, Sand, Snow, or Ice
When you drive in mud, snow, or sand, your wheels
will not get good traction. You cannot accelerate as
quickly, turning is more difficult, and you will need
longer braking distances.
It is best to use a low gear when you are in
mud — the deeper the mud, the lower the gear.
In really deep mud, the idea is to keep your vehicle
moving so you do not get stuck. Be careful to
keep mud from building up and washing onto the
engine cooling system.
When you drive on sand, you will sense a change
in wheel traction. But it will depend upon how
loosely packed the sand is. On loosely packed
sand, such as on beaches or sand dunes,
your tires will tend to sink into the sand. This has
an effect on steering, accelerating, and braking.
Drive at a reduced speed and avoid sharp turns
or abrupt maneuvers.Hard packed snow and ice offer the worst tire
traction. On these surfaces, it is very easy to lose
control. On wet ice, for example, the traction is
so poor that you will have difficulty accelerating.
And if you do get moving, poor steering and
difficult braking can cause you to slide out of
control.
{CAUTION:
Driving on frozen lakes, ponds, or rivers
can be dangerous. Underwater springs,
currents under the ice, or sudden thaws
can weaken the ice. Your vehicle could
fall through the ice and you and your
passengers could drown. Drive your
vehicle on safe surfaces only.
269

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, underbody shields,
wheels, tires, and exhaust system for damage.
Also, check the fuel lines and cooling system
for any leakage.
Your vehicle will require more frequent service
due to off-road use. See the Maintenance
Schedule for additional information.
Assist Steps
Your vehicle may be equipped with removable
side steps.
Remove the steps prior to off-roading to give your
vehicle more ground clearance and to prevent
damage to the vehicle from the side steps
dragging and/or catching on obstacles.
Notice:Do not drive off-road with the side
steps attached to your vehicle. You can damage
the side steps and/or your vehicle’s frame if
they get caught or drag against an obstacle.
This damage would not be covered by your
vehicle’s warranty. Always remove the side
steps prior to any off-road driving.
271

If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that
can make your trips safer and more enjoyable.
SeeOff-Road Driving on page 250for information
about driving off-road.
Keep your vehicle in good shape. Check all
uid levels and also the brakes, tires, cooling
system, and transmission. These parts can
work hard on mountain roads.
{CAUTION:
If you do not shift down, your 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 your engine assist
your brakes on a steep downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with
the ignition off is dangerous. Your brakes
will have to do all the work of slowing
down. They 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. Always have your
engine running and your vehicle in gear
when you go downhill.
Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when
you go down a steep or long hill.
Know how to go uphill. You may want to shift
down to a lower gear. The lower gears help
cool your engine and transmission, and you can
climb the hill better.
280

Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission uid, engine oil, axle
lubricant, belts, cooling system and brake
system. Each of these is covered in this manual,
and the Index will help you nd them quickly.
If you’re trailering, it’s a good idea to review
these sections before you start your trip.
Check periodically to see that all hitch nuts
and bolts are tight.
Trailer Wiring Harness
Light-Duty Trailer Wiring Package
If your vehicle is not equipped with 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
If you want to add on a trailer tow, it should be
installed by your dealer or a qualied service
center. Also, seeAdd-On Electrical Equipment
on page 416for more information.
307

Service........................................................ 314
Accessories and Modications................... 314
California Proposition 65 Warning.............. 315
Doing Your Own Service Work.................. 315
Adding Equipment to the Outside
of Your Vehicle...................................... 316
Fuel............................................................. 316
Gasoline Octane........................................ 316
Gasoline Specications.............................. 316
California Fuel........................................... 316
Additives................................................... 317
Fuels in Foreign Countries........................ 318
Filling the Tank......................................... 318
Filling a Portable Fuel Container............... 320
Checking Things Under the Hood.............. 321
Hood Release........................................... 321
Engine Compartment Overview.................. 322
Engine Oil................................................. 323Engine Oil Life System.............................. 326
Engine Air Cleaner/Filter............................ 328
Automatic Transmission Fluid.................... 329
Manual Transmission Fluid........................ 332
Hydraulic Clutch........................................ 334
Engine Coolant.......................................... 335
Radiator Pressure Cap.............................. 338
Engine Overheating................................... 338
Cooling System......................................... 340
Engine Fan Noise..................................... 345
Power Steering Fluid ................................. 345
Windshield Washer Fluid........................... 346
Brakes...................................................... 347
Battery...................................................... 351
Jump Starting............................................ 352
Rear Axle.................................................... 357
Four-Wheel Drive........................................ 358
Front Axle................................................... 358
Section 5 Service and Appearance Care
311

A. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 346.
B. Engine Coolant Recovery Tank. SeeEngine
Coolant on page 335.
C. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 328.
D. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 345.
E. Automatic Transmission Fluid Dipstick (If
Equipped). See “Checking the Fluid Level” under
Automatic Transmission Fluid on page 329.
F. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 323.
G. Radiator Pressure Cap. SeeCooling System
on page 340.
H. Remote Negative (−) Terminal (GND). See
Jump Starting on page 352.
I. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 323.
J. Positive (+) Battery Terminal. SeeJump
Starting on page 352.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 347.L. Engine Compartment Fuse Block. SeeEngine
Compartment Fuse Block on page 418.
M. Battery. SeeBattery on page 351.
N. Hydraulic Clutch Fluid Reservoir (If Equipped).
SeeHydraulic Clutch on page 334.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil every time
you get fuel. In order to get an accurate reading,
the oil must be warm and the vehicle must be
on level ground.
The engine oil dipstick handle is a yellow loop.
SeeEngine Compartment Overview on page 322
for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several
minutes to drain back into the oil pan. If you
do not do this, the oil dipstick might not
show the actual level.
2. Pull out the dipstick and clean it with a paper
towel or cloth, then push it back in all the
way. Remove it again, keeping the tip down,
and check the level.
323

How to Check and Add Fluid
The proper uid should be added if the level does
not reach the bottom of the diaphragm when it
is in place in the reservoir. See the instructions on
the reservoir cap.
Engine Coolant
The cooling system in your vehicle is lled with
DEX-COOL®engine coolant. This coolant is
designed to remain in your vehicle for ve years or
150,000 miles (240 000 km), whichever occurs
rst, if you add only DEX-COOL
®extended
life coolant.
The following explains your cooling system and
how to add coolant when it is low. If you have
a problem with engine overheating, seeEngine
Overheating on page 338.A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
Give freezing protection down to−34°F (−37°C).
Give boiling protection up to 265°F (129°C).
Protect against rust and corrosion.
Help keep the proper engine temperature.
Let the warning lights and gages work as
they should.
Notice:Using coolant other than DEX-COOL
®
may cause premature engine, heater core,
or radiator corrosion. In addition, the engine
coolant may require changing sooner, at
the rst maintenance service after each
30,000 miles (50 000 km) or 24 months,
whichever occurs rst. Any repairs would not
be covered by your warranty. Always use
DEX-COOL
®(silicate-free) coolant in your
vehicle.
335

What to Use
Use a mixture of one-half clean, drinkable water
and one-half DEX-COOL®coolant which will
not damage aluminum parts. If you use this coolant
mixture, you do not need to add anything else.
{CAUTION:
Adding only plain water to your cooling
system can be dangerous. Plain water, or
some other liquid such as alcohol, can
boil before the proper coolant mixture will.
Your vehicle’s coolant warning system is
set for the proper coolant mixture. With
plain water or the wrong mixture, your
engine could get too hot but you would
not get the overheat warning. Your engine
could catch re and you or others could
be burned. Use a 50/50 mixture of clean,
drinkable water and the proper coolant.Notice:If you use an improper coolant
mixture, your engine could overheat and be
badly damaged. The repair cost would not be
covered by your warranty. Too much water
in the mixture can freeze and crack the engine,
radiator, heater core, and other parts.
Notice:If you use extra inhibitors and/or
additives in your vehicle’s cooling system,
you could damage your vehicle. Use only the
proper mixture of the engine coolant listed
in this manual for the cooling system.
SeeRecommended Fluids and Lubricants
on page 440for more information.
336