2003 CHEVROLET AVALANCHE fuel

{CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the
transmission is in PARK (P). You or someone
else could be seriously injured. Be sure to set
the parking brake before placing the transfer
case in NEUTRAL. See ªParking Brakeº in the
Index.
4. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-34for the proper
procedure to select the neutral position for your
vehicle.
5. Release the parking brake only after the vehicle
being towed is ®rmly attached to the towing
vehicle.
6. When the vehicle is properly attached to the tow
vehicle and is ready to be towed, turn the ignition
to LOCK.
Loading Your Vehicle
The Certi®cation/Tire label is found on the rear edge of
the driver's door.
The label shows the size of your original tires and the
in¯ation pressures needed to obtain the gross weight
capacity of your vehicle. This is called the GVWR (Gross
Vehicle Weight Rating). The GVWR includes the
weight of the vehicle, all occupants, fuel and cargo.
4-51

Say, for example, you have a 700 lb. (318 kg) snow
plow. The total weight of all occupants and cargo inside
the cab should not exceed 300 lb. (135 kg). This
means that you may only be able to carry one
passenger. But, even this may be too much if you've
got other equipment already adding to the weight of your
vehicle.
Here are some guidelines for safely carrying a snow
plow on your vehicle:
·Make sure the weight on the front and rear axles
doesn't exceed the axle rating for each.
·For the front axle, if more cargo or passengers must
be carried, appropriate counter ballast must be
installed rear of the rear axle. Counter ballast must
be properly secured so it won't move during driving.
·Follow the snow plow manufacturer's
recommendations regarding rear ballast. Rear
ballast may be required to ensure a proper front and
rear weight distribution ratio, even though the actual
weight at the front axle may be less than the front
axle rating.
·The snow plow manufacturer or installer can assist
you in determining the amount of rear ballast
required, to help make sure your snowplow/vehicle
combination does not exceed the GVW rating, the
front and rear axle ratings, and the front and rear
weight distribution ratio.
·The total vehicle must not exceed the GVW rating.
Q:What is front axle reserve capacity, and how do
I calculate it?
A:Front axle reserve capacity is the difference
between your front GAWR and the front axle
weight of your truck with full fuel and passengers.
Basically, it's the amount of weight you can
add to your front axle before reaching your front
GAWR.
The front axle reserve capacity for your vehicle can be
found in the lower right corner of the Certi®cation/Tire
label, as shown.
United States
Canada
4-55

{CAUTION:
On some vehicles equipped with certain front
mounted equipment, such as a snow plow, it
may be possible to load the front axle to the
front GAWR but not have enough weight on
the rear axle to have proper braking
performance. If your brakes can't work
properly, you could have a crash. To help your
brakes work properly when a snow plow is
installed, always follow the snow plow
manufacturer or installer's recommendation for
rear ballast to ensure a proper front and rear
weight distribution ratio, even though the
actual front weight may be less than the front
GAWR, and the total vehicle weight is less
than the GVWR. Maintaining a proper front and
rear weight distribution ratio is necessary to
provide proper braking performance.
Q:What is total vehicle reserve capacity?
A:This is the difference between your GVWR and
the weight of your truck with full fuel and
passengers. It's the amount of weight you can add
to your vehicle before reaching your GVWR.
Keep in mind that reserve capacity numbers are
intended as a guide when selecting the amount of
equipment or cargo your truck can carry. If you
are unsure of your truck's front, rear or total weight,
go to a weigh station and weigh your vehicle.
Your dealer can also help you with this.
The total vehicle reserve capacity for your vehicle
can be found in the lower right corner of the
Certi®cation/Tire label as shown previously.
See your dealer for additional advice and information
about using a snow plow on your vehicle. Also,
see
Loading Your Vehicle on page 4-51.
Truck-Camper Loading Information
Your vehicle was neither designed nor intended to carry
a slide-in type camper.
Notice:Adding a slide-in camper or similar
equipment to your vehicle can damage it, and the
repairs wouldn't be covered by warranty. Don't
install a slide-in camper or similar equipment
on your vehicle.
4-57

If yours was built with trailering options, as many are,
it's ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment, and
it has to be used properly.
That's the reason for this part. In it are many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully before
you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:
·There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live
but also where you'll be driving. A good source for
this information can be state or provincial police.
·Consider using a sway control if your trailer will
weigh 5,000 lbs. (2 268 kg) or less. You should
always use a sway control if your trailer will weigh
more than 5,000 lbs. (2 268 kg). You can ask a
hitch dealer about sway controls.
·Don't tow a trailer at all during the ®rst 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.
·Then, during the ®rst 500 miles (800 km) that you
tow a trailer, don't drive over 50 mph (80 km/h)
and don't make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at
the heavier loads.
·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). See ªTow/Haul Modeº later in
this section.
Three important considerations have to do with weight:
·the weight of the trailer,
·the weight of the trailer tongue
·and the weight on your vehicle's tires.
4-59

Tow/Haul Mode
Tow/haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. The purpose of the
tow/haul mode is to:
·Reduce the frequency and improve the predictability
of transmission shifts when pulling a heavy trailer or
a large or heavy load.
·Provide the same solid shift feel when pulling a
heavy trailer or a large or heavy load as when
the vehicle is unloaded.
·Improve control of vehicle speed while requiring
less throttle pedal activity when pulling a heavy
trailer or a large or heavy load.
Press the button at the end of the shift lever to turn the
tow/haul feature on or off. When tow/haul is on, the
tow/haul light on the instrument panel will illuminate.
Tow/haul turns off automatically each time the vehicle is
started.Tow/haul is designed to be most effective when the
vehicle and trailer combined weight is at least 75% of
the vehicle's Gross Combination Weight Rating
(GCWR). See ªWeight of the Trailerº later in this section.
Tow/haul is most useful under the following driving
conditions:
·When pulling a heavy trailer or a large or heavy
load through rolling terrain.
·When pulling a heavy trailer or a large or heavy
load in stop and go traffic.
·When pulling a heavy trailer or a large or heavy
load in busy parking lots where improved low
speed control of the vehicle is desired.
Operating the vehicle in tow/haul when lightly loaded or
with no trailer at all will not cause damage. However,
there is no bene®t to the selection of tow/haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission driving
characteristics and reduced fuel economy. Tow/haul
is recommended only when pulling a heavy trailer or a
large or heavy load.
4-60

Service............................................................5-3
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of Your
Vehicle......................................................5-4
Fuel................................................................5-5
Gasoline Octane............................................5-5
Gasoline Speci®cations....................................5-5
California Fuel...............................................5-6
Additives.......................................................5-6
Fuels in Foreign Countries...............................5-7
Filling Your Tank............................................5-7
Filling a Portable Fuel Container.......................5-9
Checking Things Under the Hood....................5-10
Hood Release..............................................5-10
Engine Compartment Overview.......................5-12
Engine Oil...................................................5-15
Engine Air Cleaner/Filter................................5-20
Automatic Transmission Fluid.........................5-22
Engine Coolant.............................................5-24
Coolant Surge Tank Pressure Cap..................5-27
Engine Overheating.......................................5-27
Cooling System............................................5-30
Engine Fan Noise.........................................5-36Power Steering Fluid.....................................5-36
Windshield Washer Fluid................................5-38
Brakes........................................................5-39
Battery........................................................5-42
Jump Starting...............................................5-43
Rear Axle.......................................................5-49
Four-Wheel Drive............................................5-50
Front Axle......................................................5-51
Bulb Replacement..........................................5-52
Halogen Bulbs..............................................5-52
Headlamps..................................................5-52
Front Turn Signal, Sidemarker and Parking
Lamps.....................................................5-55
Front Turn Signal, Sidemarker and Daytime
Running Lamps.........................................5-56
Daytime Running Lamps................................5-58
Center High-Mounted Stoplamp (CHMSL).........5-58
Taillamps.....................................................5-58
Replacement Bulbs.......................................5-59
Windshield Wiper Blade Replacement..............5-60
Section 5 Service and Appearance Care
5-1

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle.
Gasoline Octane
Use regular unleaded gasoline with a posted octane
of 87 or higher. If the octane is less than 87, you may
get a heavy knocking noise when you drive. If this
occurs, use a gasoline rated at 87 octane or higher as
soon as possible. Otherwise, you might damage
your engine. A little pinging noise when you accelerate
or drive uphill is considered normal. This does not
indicate a problem exists or that a higher-octane fuel is
necessary. If you are using 87 octane or higher-octane
fuel and hear heavy knocking, your engine needs
service.
Gasoline Speci®cations
It is recommended that gasoline meet speci®cations
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 speci®cations could provide improved
driveability and emission control system performance
compared to other gasoline.
In Canada, look for the
ªAuto Makers' Choiceº
label on the pump.
Canada Only
5-5

California Fuel
If your vehicle is certi®ed to meet California Emission
Standards (see the underhood emission control label), it
is designed to operate on fuels that meet California
speci®cations. If this fuel is not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
speci®cations, but emission control system performance
may be affected. The malfunction indicator lamp may
turn on (see
Malfunction Indicator Lamp on page 3-41)
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
speci®cations 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.
5-6