check engine HUMMER H2 2007 Owner's Manual

Hill and Mountain Roads
Driving on steep hills or mountains is different
from driving in at or rolling terrain.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 317for 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.
351

You can run the engine to keep warm, but be
careful.
{CAUTION:
Snow can trap exhaust gases under your
vehicle. This can cause deadly CO
(carbon monoxide) gas to get inside.
CO could overcome you and kill you. You
cannot see it or smell it, so you might not
know it is in your vehicle. Clear away
snow from around the base of your
vehicle, especially any that is blocking
your exhaust pipe. And check around
again from time to time to be sure snow
does not collect there.
Open a window just a little on the side of
the vehicle that is away from the wind.
This will help keep CO out.
Run your engine only as long as you must.
This saves fuel. When you run the engine, make it
go a little faster than just idle. That is, push the
accelerator slightly. This uses less fuel for the heat
that you get and it keeps the battery charged.
356

When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal
down while you:
start your engine,
shift into a gear, and
release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the
chocks.
4. Stop and have someone pick up and store
the chocks.
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 (don’t overll),
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.
385

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

Adding Equipment to the Outside
of Your Vehicle
Things you might add to the outside of your
vehicle can affect the airow around it. This may
cause wind noise and affect windshield washer
performance. Check with your dealer before
adding equipment to the outside of your vehicle.
Fuel
Use of the recommended fuel is an important
part of the proper maintenance of your vehicle.
To help keep your engine clean and maintain
optimum vehicle performance, GM recommends
the use of gasoline advertised as TOP TIER
Detergent Gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted
octane rating of 87 or higher. If the octane rating
is less than 87, you may notice an audible
knocking noise when you drive, commonly referred
to as spark knock. If this occurs, use a gasoline
rated at 87 octane or higher as soon as possible.
If you are using gasoline rated at 87 octane or
higher and you hear heavy knocking, your engine
needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM
specication D 4814 in the United States or
CAN/CGSB-3.5 in Canada. Some gasolines may
contain an octane-enhancing additive called
methylcyclopentadienyl manganese tricarbonyl
(MMT). General Motors recommends against the
use of gasolines containing MMT. SeeAdditives
on page 395for additional information.
394

California Fuel
If your vehicle is certied to meet California
Emissions Standards, it is designed to operate
on fuels that meet California specications.
See the underhood emission control label.
If this fuel is not available in states adopting
California emissions standards, your vehicle will
operate satisfactorily on fuels meeting federal
specications, but emission control system
performance may be affected. The malfunction
indicator lamp may turn on and your vehicle may
fail a smog-check test. SeeMalfunction Indicator
Lamp on page 215. If this occurs, return to
your authorized GM dealer for diagnosis. If it is
determined that the condition is caused by the type
of fuel used, repairs may not be covered by
your warranty.
Additives
To provide cleaner air, all gasolines in the
United States are now required to contain additives
that will help prevent engine and fuel system
deposits from forming, allowing your emission
control system to work properly. In most cases,
you should not have to add anything to your fuel.
However, some gasolines contain only the
minimum amount of additive required to meet
U.S. Environmental Protection Agency regulations.
To help keep fuel injectors and intake valves
clean, or if your vehicle experiences problems due
to dirty injectors or valves, look for gasoline that
is advertised as TOP TIER Detergent Gasoline.
Also, your dealer has additives that will help
correct and prevent most deposit-related problems.
395

Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine
parts and start a re. These include
liquids like fuel, oil, coolant, brake uid,
windshield washer and other uids, and
plastic or rubber. You or others could be
burned. Be careful not to drop or spill
things that will burn onto a hot engine.
Hood Release
To open the hood, do the following:
1. Release both hood side latches.
2. Pull the handle with
this symbol on it.
It is located inside
the vehicle to the
lower left of the
steering column.
400

A. Coolant Surge Tank. SeeCooling System on
page 420andCoolant Surge Tank Pressure
Cap on page 418.
B. Engine Air Cleaner/Filter and Air Filter
Restriction Indicator (If Equipped). SeeEngine
Air Cleaner/Filter on page 409.
C. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 426.
D. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil on page 404.
E. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 404.
F. Automatic Transmission Fluid Dipstick.
See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 412.G. Engine Cooling Fan. SeeCooling System on
page 420.
H. Remote Negative (−) Terminal (GND).
SeeJump Starting on page 432.
I. Power Steering Fluid Reservoir (Out of View).
SeePower Steering Fluid on page 425.
J. Remote Positive (+) Terminal. SeeJump
Starting on page 432.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 427.
L. Underhood Fuse Block. SeeUnderhood Fuse
Block on page 507.
M. Battery. SeeBattery on page 431.
403

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

If you are in an area of extreme cold, where the
temperature falls below−20°F (−29°C), it is
recommended that you use either an SAE 5W-30
synthetic oil or an SAE 0W-30 oil. Both will
provide easier cold starting and better protection
for the engine at extremely low temperatures.
Engine Oil Additives
Do not add anything to the oil. The recommended
oils with the starburst symbol that meet GM
Standard GM6094M are all you will need for good
performance and engine protection.
Engine Oil Life System
When to Change Engine Oil
Your vehicle has a computer system that lets you
know when to change the engine oil and lter.
This is based on engine revolutions and engine
temperature, and not on mileage. Based on driving
conditions, the mileage at which an oil change
will be indicated can vary considerably.For the oil life system to work properly, you must
reset the system every time the oil is changed.
When the system has calculated that oil life
has been diminished, it will indicate that an oil
change is necessary. A CHANGE ENGINE
OIL message will come on. Change your oil as
soon as possible within the next 600 miles
(1 000 km). It is possible that, if you are driving
under the best conditions, the oil life system may
not indicate that an oil change is necessary for
over a year. However, your engine oil and
lter must be changed at least once a year and at
this time the system must be reset. Your dealer
has GM-trained service people who will perform
this work using genuine GM parts and reset
the system. It is also important to check your oil
regularly and keep it at the proper level.
If the system is ever reset accidentally, you must
change your oil at 3,000 miles (5 000 km) since
your last oil change. Remember to reset the oil life
system whenever the oil is changed.
407