1999 CHEVROLET SILVERADO fuel cap

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This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn't come on, have it repaired.
This light will also come on during a malfunction in one
of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:

Reducing vehicle speed.

Avoiding hard accelerations.

Avoiding steep uphill grades.

If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.If the light stops flashing and remains on steady, see ªIf
the Light Is On Steadyº following.
If the light continues to flash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart the
engine. If the light remains on steady, see ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. See ªFilling Your Tankº in the Index. The
diagnostic system can determine if the fuel cap has been
left off or improperly installed. A loose or missing fuel
cap will allow fuel to evaporate into the atmosphere.
A few driving trips with the cap properly installed
should turn the light off.
Did you just drive through a deep puddle of water?

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2-81 Tow/Haul Light (Automatic
Transmissions Only)
This message is displayed
when the tow/haul mode has
been activated.
For more information see, ªTow/Haul Modeº in
the Index.
Fuel Gage
The fuel gage, when the
ignition is on, tells you
about how much fuel you
have left in your tank.The gage will first indicate E (Empty) before you are
out of fuel, and you should get more fuel as soon
as possible.
Here are four situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.

At the gas station, the fuel pump shuts off before the
gage reads F (Full).

It takes a little more or less fuel to fill up than the
fuel gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank's capacity to fill
the tank.

The gage goes back to E (Empty) when you turn off
the ignition.
If you have a diesel engine, see ªFuel Gageº in the
Diesel Engine Supplement.

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The system will automatically switch to the recirculation
mode to lower the system load and improve interior
comfort. The OUTSIDE AIR and RECIRCULATION
button LEDs will not change. The system will return to
the OUTSIDE AIR function when the system load
is reduced.
A/C: Press this button to turn the air conditioning
on and off. The system will cool and dehumidify the air
inside the vehicle when the A/C light is on.
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which air
conditioning is ineffective.
Air Conditioning
On hot days, open the windows long enough to let hot
air inside escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
The RECIRCULATION button, below the fan knob,
allows the air inside your vehicle to be recirculated. This
setting helps to maximize your air conditioner's
performance and your vehicle's fuel economy. This
setting also cools air the fastest and can be used to keep
unwanted odors and/or dust from entering the vehicle.
When using the air conditioner, turn off theRECIRCULATION button after the vehicle reaches a
comfortable interior temperature. When the right knob
on the control panel is between HEATER and
DEFROST, the recirculation feature will not function to
reduce window fogging.
The A/C button, below the mode knob, allows the air
coming into your vehicle to be cooled. This setting is
useful for normal cooling on hot days. When you use
A/C with the RECIRCULATION button pushed in, turn
off recirculation as soon as the vehicle reaches a
comfortable interior temperature.
Maximum air conditioning performance is obtained by
pressing the A/C button, the RECIRCULATION button
and turning the temperature knob fully counterclockwise
to the blue area. This setting also cools air the fastest.
After the vehicle's interior reaches a comfortable
temperature, press the OUTSIDE AIR button to place
the air conditioning system in the normal mode.
Passenger Compartment Air Filter (If Equipped)
Your vehicle may be equipped with a passenger
compartment air filter, which filters outside air entering
the vehicle. For information on replacing the filter see
ªPassenger Compartment Air Filterº in the Index.

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Loading Your Vehicle
The Certification/Tire label is found on the rear edge of
the driver's door.
The label shows the size of your original tires and the
inflation 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.The Certification/Tire label also tells you the maximum
weights for the front and rear axles, called Gross Axle
Weight Rating (GAWR). To find out the actual loads on
your front and rear axles, you need to go to a weigh
station and weigh your vehicle. Your dealer can help
you with this. Be sure to spread out your load equally on
both sides of the centerline.
Never exceed the GVWR for your vehicle, or the
GAWR for either the front or rear axle.
The Certification/Tire label also contains information
about your Front Axle Reserve Capacity. See ªFront
Axle Reserve Capacityº later in this section.
And, if you do have a heavy load, you should spread
it out.CAUTION:
In the case of a sudden stop or collision, things
carried in the bed of your truck could shift
forward and come into the passenger area,
injuring you and others. If you put things in the
bed of your truck, you should make sure they are
properly secured.

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4-49 Front Axle Reserve Capacity
This is the difference between your front GAWR and the
front axle weight of your truck with full fuel and
passengers. It is 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 hand corner of the
tire/certification label, as
shown in this example.In order to calculate the amount of weight any
front accessory is adding to the front axle, use the
following formula.
(W x (A+W.B.)) / W.B.= Weight the accessory is adding
to the front axle
Where: W= Weight of added accessory
A= Distance that the accessory is
in front of the front axle
W.B.= Vehicle Wheelbase

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For example, adding a 700 lb. ( 318 kg) snow plow
adds more than 700 lb. ( 318 kg) to the front axle.
Using the formula, if the snow plow is 4 ft. (122 cm)
in front of the front axle and the wheel base is
10 ft. (305 cm), then:
W= 700 lb. ( 318 kg), A= 4 ft. (122 cm) and W.B.=
10 ft. (305 cm)
(W x (A+W.B.)) / W.B. = (700 x (4ft. + 10 ft.)) /
10 ft. = 980 lbs.
So, if your truck's front axle reserve capacity is more
than 980 lbs. (445 kg), you could add this snow plow
without exceeding the front GAWR.
You can add heavier equipment on the front of the
vehicle if you compensate for it by carrying fewer
passengers, less cargo or by positioning cargo more
towards the rear. This has the effect of reducing the load
on the front. However, the front GAWR, rear GAWR
and the GVWR must never be exceeded.Total Vehicle Reserve Capacity
This is the difference between your GVWR and the
weight of your truck with full fuel and passengers. It is
the amount of weight you can add to your vehicle before
reaching your GVWR.
The 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 help you with this.
Truck-Camper Loading Information
This label is inside your glove box. It will tell you if
your vehicle can carry a slide
-in camper, how much of a
load your vehicle can carry, and how to correctly spread
out your load. Also, it will help you match the right
slide
-in camper to your vehicle.
When you carry a slide
-in camper, the total cargo load
of your vehicle is the weight of the camper, plus

everything else added to the camper after it left
the factory,

everything in the camper and

all the people inside.

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4-54
Your vehicle can tow a trailer. 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 less than the capacity stamped on your step
bumper. You should always use a sway control if
your trailer will weigh more than the capacity
stamped on your step bumper. You can ask a hitch
dealer about sway controls.
Don't tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.

Then, during the first 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.

If you have an automatic transmission, 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 in the Index. If you have a
manual transmission and you are towing a trailer, it's
better not to use FIFTH (5) gear. Just drive in
FOURTH (4) gear (or, as you need to, a lower gear).
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.

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Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel (Gasoline Engine)
6
-5 Fuels in Foreign Countries (Gasoline Engines)
6
-6 Filling Your Tank (Gasoline Engine)
6
-8 Checking Things Under the Hood
6
-12 Engine Oil (Gasoline Engine)
6
-16 Engine Air Cleaner/Filter
6
-19 Automatic Transmission Fluid
6
-22 Manual Transmission Fluid
6
-24 Hydraulic Clutch
6
-25 Rear Axle
6
-25 Four-Wheel Drive
6
-28 Coolant Surge Tank Pressure Cap
(Gasoline Engine)
6
-28 Thermostat
6
-29 Engine Coolant
6
-32 Power Steering Fluid6
-33 Windshield Washer Fluid
6
-34 Brakes
6
-37 Battery
6
-38 Bulb Replacement
6
-44 Windshield Wiper Blade Replacement
6
-45 Tires
6
-54 Appearance Care
6
-54 Cleaning the Inside of Your Vehicle
6
-58 Cleaning the Outside of Your Vehicle
6
-62 GM Vehicle Care/Appearance Materials
6
-63 Vehicle Identification Number (VIN)
6
-64 Electrical System
6
-73 Replacement Bulbs
6
-74 Capacities and Specifications
6
-76 Air Conditioning Refrigerants
6
-77 Normal Maintenance Replacement Parts