warning HUMMER H2 2007 Owner's Guide

Selectable Extended Rear Ride
Height
If your vehicle has this feature it comes as part
of the electronically controlled air suspension
system.
The selectable rear ride height allows you to raise
the rear of the vehicle about 2 inches (5 cm)
over the normal ride height. This can be helpful
when driving off-road where you may need
more ground clearance to clear an obstacle.
The button that controls
this feature is located
on the instrument panel
to the right of the
steering wheel.To use this feature, ensure that the following
conditions are met:
The engine must be running.
All doors must be fully closed. The suspension
will not raise or lower if a door is open.
The vehicle speed must be less than 40 mph
(64 km/h). The system will not activate
otherwise.
Press the height control button to raise the rear of
the vehicle.
A light in the button will begin to ash as the rear
of the vehicle rises. Once the extended height
has been reached (this may take up to a minute),
the warning light will stop ashing and will stay
lit while the vehicle is at the extended height.
371

You may also hear the release of air similar to a
hissing sound during suspension operation.
This is normal.
Load leveling will not function normally with the
inator hose attached to the inator outlet.
Remove the inater hose from the outlet when
it is not in use. SeeAccessory Inator on
page 466.
Overload and Overheat Protection
Overload protection is designed to protect the air
suspension system and is an indication to the
driver that the vehicle is overloaded.
If the rear suspension remains at a low height, the
rear axle load has exceeded GAWR (Gross Axle
Weight Rating). When the overload protection
mode is activated, the compressor operates forabout 30 seconds to one minute without raising the
vehicle depending on the amount of overload.
This will continue each time the ignition is turned on
until the rear axle load is reduced below GAWR.
If the total rear GAWR (Gross Axle Weight Rating)
is reached, the suspension may be slightly less
than level. This is normal and does not mean there
is a problem with the air suspension.
If the system overheats due to normal operation,
the SERVICE AIR SUSPENSION message
will not be displayed on the DIC, but the system
will shut down and stop all leveling functions until it
cools down. If the system overheats and sets
the SERVICE AIR SUSPENSION message in the
DIC, then there is a fault. SeeDIC Warnings
and Messages on page 226for more information.
373

Driving On Grades
Reduce speed and shift to a lower gearbefore
you start down a long or steep downgrade. If you
don’t shift down, you might have to use your
brakes so much that they would get hot and no
longer work well.
You can tow in DRIVE (D). You may want to shift
the transmission to THIRD (3) or, if necessary,
a lower gear selection if the transmission shifts too
often (e.g., under heavy loads and/or hilly
conditions).
You may also want to activate the tow/haul mode
if the transmission shifts too often. See “Tow/Haul
Mode” earlier.
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 you
turn your engine off immediately after towing at high
altitude on steep uphill grades, your 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
PARK (P) for a few minutes before turning the
engine off. If you do get the overheat warning,
seeEngine Overheating on page 418.
Parking on Hills
{CAUTION:
You really should not park your
vehicle, with a trailer attached, on a hill.
If something goes wrong, your rig could
start to move. People can be injured, and
both your vehicle and the trailer can be
damaged.
But if you ever have to park your rig on a hill,
here’s how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release
the regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
384

Service........................................................ 392
Accessories and Modications................... 392
California Proposition 65 Warning.............. 393
Doing Your Own Service Work.................. 393
Adding Equipment to the Outside of
Your Vehicle.......................................... 394
Fuel............................................................. 394
Gasoline Octane........................................ 394
Gasoline Specications.............................. 394
California Fuel........................................... 395
Additives................................................... 395
Fuels in Foreign Countries........................ 396
Filling the Tank......................................... 397
Filling a Portable Fuel Container............... 399
Checking Things Under the Hood.............. 400
Hood Release........................................... 400
Engine Compartment Overview.................. 402
Engine Oil................................................. 404
Engine Oil Life System.............................. 407
Engine Air Cleaner/Filter............................ 409
Automatic Transmission Fluid.................... 412
Engine Coolant.......................................... 415Coolant Surge Tank Pressure Cap............ 418
Engine Overheating................................... 418
Overheated Engine Protection
Operating Mode..................................... 420
Cooling System......................................... 420
Power Steering Fluid ................................. 425
Windshield Washer Fluid........................... 426
Brakes...................................................... 427
Battery...................................................... 431
Jump Starting............................................ 432
Rear Axle.................................................... 437
Four-Wheel Drive........................................ 438
Front Axle................................................... 440
Bulb Replacement....................................... 441
Halogen Bulbs........................................... 441
Headlamps................................................ 441
Front Turn Signal and Parking Lamps.......... 442
Daytime Running Lamps (DRL)................. 443
Roof Marker Lamps................................... 443
Taillamps, Turn Signal, Stoplamps and
Back-up Lamps...................................... 444
Replacement Bulbs................................... 446
Section 5 Service and Appearance Care
389

California Proposition 65 Warning
Most motor vehicles, including this one, contain
and/or emit chemicals known to the State of
California to cause cancer and birth defects or other
reproductive harm. Engine exhaust, many parts and
systems (including some inside the vehicle), many
uids, and some component wear by-products
contain and/or emit these chemicals.
Doing Your Own Service Work
{CAUTION:
You can be injured and your vehicle could
be damaged if you try to do service work
on a vehicle without knowing enough
about it.
Be sure you have sufficient knowledge,
experience, the proper replacement
parts, and tools before you attempt any
vehicle maintenance task.
CAUTION: (Continued)
CAUTION: (Continued)

Be sure to use the proper nuts, bolts,
and other fasteners. English and
metric fasteners can be easily
confused. If you use the wrong
fasteners, parts can later break or fall
off. You could be hurt.
If you want to do some of your own service work,
you will want to use the proper service manual.
It tells you much more about how to service your
vehicle than this manual can. To order the
proper service manual, seeService Publications
Ordering Information on page 553.
Your vehicle has an airbag system. Before
attempting to do your own service work, see
Servicing Your Airbag-Equipped Vehicle on
page 88.
You should keep a record with all parts receipts
and list the mileage and the date of any service
work you perform. SeeMaintenance Record
on page 532.
393

{CAUTION:
If you spill fuel and then something
ignites it, you could be badly burned.
Fuel can spray out on you if you open the
fuel cap too quickly. This spray can
happen if your tank is nearly full, and is
more likely in hot weather. Open the fuel
cap slowly and wait for any hiss noise to
stop. Then unscrew the cap all the way.
Be careful not to spill fuel. Do not top off or overll
the tank and wait a few seconds after you have
nished pumping before removing the nozzle.
Clean fuel from painted surfaces as soon as
possible. SeeWashing Your Vehicle on page 495.When replacing the fuel cap, turn it clockwise
until it clicks. Make sure the cap is fully installed.
The diagnostic system can determine if the
fuel cap has been left off or improperly installed.
This would allow fuel to evaporate into the
atmosphere. SeeMalfunction Indicator Lamp
on page 215.
The TIGHTEN FUEL CAP message will be
displayed on the Driver Information Center (DIC)
if the fuel cap is not properly installed.
SeeDIC Warnings and Messages on page 226
for more information.
398

Engine Oil
If the CHECK OIL LEVEL message appears on
the Driver Information Center (DIC), it means you
need to check the engine oil level right away.
For more information, see CHECK OIL LEVEL
underDIC Warnings and Messages on page 226.
You should check the engine oil level regularly;
this is an added reminder.
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 402
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.
404

How to Reset the Engine Oil
Life System
The Engine Oil Life System calculates when to
change your engine oil and lter based on vehicle
use. Anytime your oil is changed, reset the system
so it can calculate when the next oil change is
required. If a situation occurs where you change
your oil prior to a CHANGE ENGINE OIL message
being turned on, reset the system.
To reset the CHANGE ENGINE OIL message,
see “Engine Oil Life System” underDIC Operation
and Displays on page 222for vehicles that
have the DIC, or do the following:
1. Turn the ignition key to RUN with the engine off.
2. Fully press and release the accelerator pedal
slowly three times within ve seconds.
If the OIL LIFE RESET message ashes for
10 seconds, the system is resetting.
3. Turn the key to LOCK.
If the CHANGE ENGINE OIL message comes
back on when you start your vehicle, the engine oil
life system has not reset. Repeat the procedure.
If it still does not reset, see your dealer for service.
What to Do with Used Oil
Used engine oil contains certain elements that
may be unhealthy for your skin and could
even cause cancer. Do not let used oil stay on
your skin for very long. Clean your skin and nails
with soap and water, or a good hand cleaner.
Wash or properly dispose of clothing or rags
containing used engine oil. See the manufacturer’s
warnings about the use and disposal of oil
products.
Used oil can be a threat to the environment. If you
change your own oil, be sure to drain all the oil
from the lter before disposal. Never dispose of oil
by putting it in the trash, pouring it on the
ground, into sewers, or into streams or bodies of
water. Instead, recycle it by taking it to a place
that collects used oil. If you have a problem
properly disposing of your used oil, ask your
dealer, a service station, or a local recycling
center for help.
408

Notice:Use of the incorrect automatic
transmission uid may damage your vehicle,
and the damages may not be covered by
your warranty. Always use the automatic
transmission uid listed inRecommended
Fluids and Lubricants on page 528.
After adding uid, recheck the uid level as
described under “How to Check Automatic
Transmission Fluid,” earlier in this section.
When the correct uid level is obtained, push
the dipstick back in all the way; then ip the
handle down to lock the dipstick in place.
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 418.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.
415

What Kind of Coolant 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 DEX-COOL
®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.
If you have to add coolant more than four times a
year, have your dealer check your cooling
system.
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. See
Recommended Fluids and Lubricants on
page 528for more information.
416