2003 GMC SIERRA Owner's Manual

Gasoline Specifications
It is recommended that gasoline meet specifications
which were developed by the American Automobile
Manufacturers Association and endorsed by the
Canadian Vehicle Manufacturers Association for better
vehicle performance and engine protection. Gasoline
meeting these specifications could provide improved
driveability and emission control system performance
compared to other gasoline.
In Canada, look for the
“Auto Makers’Choice”
label on the pump.
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 (seeMalfunction Indicator Lamp on page 3-37)
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.
Canada Only
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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.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel may be hard
tofind. 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’tbe
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.
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Filling Your Tank
{CAUTION:
Fuel vapor is highly 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.
The fuel cap is located behind a hinged door on the
driver’s side of the vehicle.
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While refueling, hang the fuel cap by the tether using
the hook located on the inside of thefiller door.
To remove the fuel cap, turn it slowly to the left
(counterclockwise).
{CAUTION:
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. SeeCleaning the Outside
of Your Vehicle on page 5-85.
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. SeeMalfunction Indicator Lamp on
page 3-37.
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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 notfit 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 Fuel Container
{CAUTION:
Neverfill a portable 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:
•Dispense gasoline only into approved
containers.
•Do notfill a container while it is inside a
vehicle, in a vehicle’s trunk, pickup bed or
on any surface other than the ground.
•Bring thefill nozzle in contact with the
inside of thefill opening before operating
the nozzle. Contact should be maintained
until thefilling is complete.
•Don’t smoke while pumping gasoline.
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Checking Things Under
the Hood
{CAUTION:
Things that burn can get on hot engine parts
and start afire. These include liquids like fuel,
oil, coolant, brakefluid, windshield washer and
otherfluids, 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.
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2. Then go to the front of the vehicle and pull up on
the secondary hood release located near the
center of the grill.
3. Lift the hood.
Before closing the hood, be sure allfiller caps are
on properly. Pull down the hood and close itfirmly.
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Engine Compartment Overview
When you lift the hood on the VORTEC™6000 V8 engine, you’ll see:
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