2009 HUMMER H2 cooling

ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 5-33for further
information.
This message also displays when the vehicle’s engine
power is reduced. Reduced engine power can affect the
vehicle’s ability to accelerate. If this message is on, but
there is no reduction in performance, proceed to your
destination. The performance may be reduced the next
time the vehicle is driven. The vehicle may be driven at a
reduced speed while this message is on, but acceleration
and speed may be reduced. Anytime this message stays
on, the vehicle should be taken to your dealer/retailer for
service as soon as possible.
FUEL LEVEL LOW
This message displays and a chime sounds if the fuel
level is low. Refuel as soon as possible. SeeFuel Gage
on page 3-45andFuel on page 5-5for more information.
HEATED WASHER FLUID SYSTEM OFF
This message displays when the heated windshield
washer has been turned off. SeeWindshield Washer
on page 3-10for more information.
HEATING WASH FLUID WASH WIPES
PENDING
This message displays when the heated windshield
washer system is heating the uid. SeeWindshield
Washer on page 3-10for more information.
HOOD OPEN
This message displays and a chime sounds if the hood
is not fully closed. Stop and turn off the vehicle, check the
hood for obstructions, and close the hood again. Check to
see if the message still appears on the DIC.
ICE POSSIBLE DRIVE WITH CARE
This message displays when ice conditions are possible.
LEFT REAR DOOR OPEN
This message displays and a chime sounds if the driver
side rear door is not fully closed and the vehicle is shifted
out of P (Park). Stop and turn off the vehicle, check the
door for obstructions, and close the door again. Check to
see if the message still appears on the DIC.
3-58

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 4-34.
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.
4-32

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.
{CAUTION:
Coasting downhill in N (Neutral) or with the ignition
off is dangerous. The brakes will have to do all the
work of slowing down and 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 the engine running
and the vehicle in gear when going downhill.
Stay in your own lane. Do not swing wide or cut
across the center of the road. Drive at speeds
that let you stay in your own lane.
Top of hills: Be alert — something could be in your
lane (stalled car, accident).
Pay attention to special road signs (falling rocks
area, winding roads, long grades, passing or
no-passing zones) and take appropriate action.
SeeOff-Road Driving on page 4-15for information
about driving off-road.
4-36

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
Heavy-Duty Trailer Wiring Harness
Package
The vehicle is equipped with the seven-wire trailer towing
harness. This harness with a seven-pin universal trailer
connector is attached to a bracket on the hitch platform.The seven-wire harness contains the following trailer
circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Taillamps
White: Ground
Light Green: Back-up Lamps
Red/Black: Battery Feed*
Dark Blue: Trailer Brake*
*There is a location in the Underhood Fuse Block for
these circuits, but they are not connected. They should
be connected, and proper fuses installed, by your
dealer/retailer or a qualied service center.
If charging a remote (non-vehicle) battery, press the
Tow/Haul mode button located at the end of the
shift lever. This will boost the vehicle system voltage
and properly charge the battery.
4-67

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................................................................5-5
Gasoline Octane............................................5-5
Gasoline Specications....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuel E85 (85% Ethanol)..................................5-7
Fuels in Foreign Countries...............................5-8
Filling the Tank..............................................5-8
Filling a Portable Fuel Container.....................5-10
Checking Things Under the Hood....................5-11
Hood Release..............................................5-12
Engine Compartment Overview.......................5-14
Engine Oil...................................................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-23
Cooling System............................................5-27
Engine Coolant.............................................5-31
Engine Overheating.......................................5-33Overheated Engine Protection
Operating Mode.........................................5-35
Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-37
Brakes........................................................5-38
Battery........................................................5-41
Jump Starting...............................................5-42
Rear Axle.......................................................5-47
Four-Wheel Drive............................................5-48
Front Axle......................................................5-49
Bulb Replacement..........................................5-50
Halogen Bulbs..............................................5-50
Headlamps..................................................5-51
Front Turn Signal and Parking Lamps..............5-52
Daytime Running Lamps (DRL).......................5-52
Roof Marker Lamps......................................5-53
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps.........................................5-54
Replacement Bulbs.......................................5-55
Windshield Wiper Blade Replacement..............5-56
Tires..............................................................5-57
Tire Sidewall Labeling...................................5-58
Tire Terminology and Denitions.....................5-60
Ination - Tire Pressure.................................5-63
Tire Pressure Monitor System.........................5-64
Section 5 Service and Appearance Care
5-1

A. Coolant Surge Tank. SeeCooling System on
page 5-27.
B. Engine Air Cleaner/Filter and Air Filter Restriction
Indicator (If Equipped). SeeEngine Air Cleaner/Filter
on page 5-20.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-37.
D. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
E. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
F. Air Filter Restriction Indicator (If Equipped).
SeeEngine Air Cleaner/Filter on page 5-20.
G. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-23.
H. Engine Cooling Fan. SeeCooling System on
page 5-27.
I. Remote Negative (−) Terminal (GND). SeeJump
Starting on page 5-42.
J. Power Steering Fluid Reservoir (Out of View).
SeePower Steering Fluid on page 5-36.K. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
L. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-38.
M.Underhood Fuse Block on page 5-113.
N.Battery on page 5-41.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel ll. 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. See
Engine Compartment Overview on page 5-14for
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 this is not done, 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.
5-15

Cooling System
When you decide it is safe to lift the hood, here is what
you will see:
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan{CAUTION:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
If the coolant inside the coolant surge tank is boiling, do
not do anything else until it cools down. The vehicle
should be parked on a level surface. Check the coolant
level after the system cools down. Some amount of
coolant may be lost due to overheating.
5-27

The coolant level should be at or above the FULL
COLD mark. If it is not, you may have a leak at the
pressure cap or in the radiator hoses, heater hoses,
radiator, water pump, or somewhere else in the cooling
system.
{CAUTION:
Heater and radiator hoses, and other engine parts,
can be very hot. Do not touch them. If you do, you
can be burned.
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine re, and you could be burned.
Get any leak xed before you drive the vehicle.
If there seems to be no leak, start the engine again.
The engine cooling fan speed should increase when idle
speed is doubled by pushing the accelerator pedal down.
If it does not, the vehicle needs service. Turn off the
engine.Notice:Engine damage from running your engine
without coolant is not covered by your warranty. See
Overheated Engine Protection Operating Mode on
page 5-35for information on driving to a safe place
in an emergency.
Notice:Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 30,000 miles (50 000 km)
or 24 months, whichever occurs rst. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant in
the vehicle.
How to Add Coolant to the Coolant
Surge Tank
If you have not found a problem yet, check to see if
coolant is visible in the surge tank. If coolant is visible
but the coolant level is not at or above the FULL COLD
mark, add a 50/50 mixture of clean, drinkable water
and DEX-COOL
®coolant at the coolant surge tank, but
be sure the cooling system, including the coolant
surge tank pressure cap, is cool before you do it. See
Engine Coolant on page 5-31for more information.
5-28