2003 GMC SIERRA DENALI fuel

California Fuel
If your vehicle is certified to meet California Emission
Standards (see the underhood emission control label),
it is designed to operate on fuels that meet California
specifications. If this fuel is not available
in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see
Malfunction lndicator Lamp on page 3-38 )
and your vehicle may fail a smog-check test. 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.
You should not have
to add anything to your fuel. Gasolines containing
oxygenates, such as ethers and
ethanol, and reformulated gasolines may be available in
your area to contribute
to clean air. General Motors
recommends that you use these gasolines, particularly
if
they comply with the specifications described earlier.
Notice: Your vehicle was not designed for fuel
that contains methanol. Don’t use fuel containing
methanol.
It can corrode metal parts in your
fuel system and also damage the plastic and rubber
parts. That damage wouldn’t be covered under
your warranty.
Some gasolines that are not reformulated for low
emissions may contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. General Motors does
not recommend the use of such gasolines. Fuels
containing MMT can reduce the life of spark plugs and
the performance of the emission control system may
be affected. The malfunction indicator lamp may turn on.
If this occurs, return to your authorized GM dealer
for service.
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Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
to
find. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel wouldn’t be
covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major
oil company that does business in the
country where you’ll be driving.
Filling Your Tank
Fuel va,_ r is hi,---, flammable. It burns
violently, and that can cause very bad injuries.
Don’t smoke if you’re near fuel or refueling
your vehicle. Keep sparks, flames and smoking
materials away from fuel.
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While refueling, hang the fuel cap by the tether using
the hook located on the inside of the filler door.
To remove the fuel cap, turn it slowly to the left
(counterclockwise).
- -
If you get fuel on yourself 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. Clean fuel from painted
surfaces as
soon as possible. See Cleaning the Outside
of Your Vehicle on page 5-88.
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When you put the fuel cap back on, turn it to the right
(clockwise) until you hear a clicking sound. Make
sure you fully install the cap. 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. See
Malfunction Indicator lamp on
page 3-38.
Notice: If you need a new fuel cap, be sure to get
the right type. Your dealer can get one for you. If you get the wrong type,
it may not fit properly.
This may cause your malfunction indicator lamp to
light and may damage your fuel tank and emissions
system. See “Malfunction Indicator Lamp” in the
Index.
Filling a Portable Fue ‘~er
Never fill -)ortable fuel container while it is in
your vehicle. Static electricity discharge from
the container can ignite the gasoline vapor.
You can be badly burned and your vehicle
damaged if
this occurs. To help avoid injury to
you and others:
0 Dispense gasoline only into approved
containers.
Do not fill a container while it is inside a
vehicle,
in a vehicle’s trunk, pickup bed or
on any surface other than the ground.
0 Bring the fill nozzle in contact with the
inside of the fill opening before operating
the nozzle. Contact should be maintained until the filling
is complete.
Don’t smoke while pumping gasoline.
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Checking Things Under
1-eH
od
Things ti.-- burn c2.. get on hot engine parts
and start a fire. These include liquids like fuel,
oil, coolant, brake fluid, windshield washer and
other fluids, 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. Pull the handle inside
the vehicle located
under and to the left
of
the steering wheel.
5-1 0

Checking Engine Oil
It’s a good idea to check your 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 has
a yellow looped handle
and is located on the
passenger’s side of the
vehicle. See
Engine
Compartment
Overview
on page 5- 12 for more
information on location. Turn
off the
engine and give the oil several minutes to
drain back into the oil pan.
If you don’t, the oil dipstick
might not show the actual level.
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.
5-1 4

As in the chart shown previously, SAE 5W-30 is the
only viscosity grade recommended for your vehicle.
You should look for and use only oils which have the
API Starburst symbol and which are also identified
as SAE 5W-30. If you cannot find such SAE 5W-30 oils,
you can use an SAE IOW-30 oil which has the API
Starburst symbol,
if it's going to be 0°F (-18°C)
or above. Do not use other viscosity grade oils, such as
SAE 1OW-40 or SAE 20W-50 under any conditions.
Notice: Use only engine oil with the American
Petroleum Institute Certified For Gasoline Engines
starburst symbol. Failure to use the recommended
oil can result in engine damage not covered by
your warranty.
GM Goodwrench@ oil meets all the requirements for
your vehicle.
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 OW-30 oil. Both will provide
easier cold starting and better protection for your engine
at extremely
low temperatures.
Engine Oil Additives
Don't add anything to your oil. The recommended oils
with the starburst symbol are all you will need for
good performance and engine protection.
When to Change Engine Oil
(GM Oil Life SystemTM)
Your vehicle has a computer system that lets you know
when to change the engine
oil and filter. 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 SOON message will come on.
Change your oil as soon as possible within the next two
times you stop for fuel. 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 filter must be changed at
least once a year and at this time the system must be
reset. 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.
5-1 7

6. Then replace the
pressure cap. Be sure
the pressure cap is
hand-tight and
fully seated. Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When the
clutch is engaged, the fan spins faster to provide more air
to cool the engine. In most everyday driving conditions,
the fan is spinning slower and the clutch is not fully
engaged. This improves fuel economy and reduces fan
noise. Under heavy vehicle loading, trailer towing and/or
high outside temperatures, the fan speed increases as
the clutch more fully engages.
So you may hear an
increase in fan noise. This is normal and should not be
mistaken as the transmission slipping or making extra
shifts. It
is merely the cooling system functioning properly.
The fan will slow down when additional cooling is not
required and the clutch disengages.
You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
5-36