2002 GMC SIERRA 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.

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Here are some 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 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 empty when you turn off
the ignition.
Message Center
The message center is located on the left side of the
instrument panel cluster. It gives you important safety
and maintenance facts. When you turn the ignition on,
the entire center lights up for just a few seconds.
As needed, the message center will display one of the
following messages. The message center is capable
of alternating among different messages if needed.
Battery
If this message is displayed
when the engine is running,
you may have a problem
with your charging system.
The battery display will also stay on while the key is in
RUN until the engine is started.
If the message stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this message displayed could drain
your battery.
If you must drive a short distance with this message
displayed, it helps to turn off all your accessories,
such as the radio and the air conditioner.

3-4
Recirculation will not be available in floor, blend, or
defrost modes. This helps reduce window fogging.
If the recirculation button is pressed in these modes,
the LED indicator for recirculation will flash three times
indicating that outside air is activated and recirculation
is not available.
If the air conditioning system is activated and system
demand is high in situations such as city traffic, idling,
or very hot weather, the system will automatically
switch from outside air to recirculation. The LED
indicator will not change. After demand on the system
is reduced, the system will return to outside air.
A/C (Air Conditioning): This button is used to
control the air conditioning compressor. Turning the
system on will allow air to be cooled and dehumidified
inside the vehicle.
Air conditioning will be automatically disabled when
the outside air temperature drops below a level at which
air conditioning is effective.
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 A/C button, located 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 air conditioning with the recirculation button
pressed, turn off recirculation as soon as the vehicle
reaches a comfortable interior temperature.
Using air conditioning with the recirculation mode
active 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 recirculation and use outside air after the vehicle
reaches a comfortable interior temperature. When the
right knob on the control panel is between floor and
defrost, recirculation will not function to reduce window
fogging.

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Recreational Vehicle Towing
Recreational vehicle towing means towing your vehicle
behind another vehicle
-- such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as ªdinghy towingº (towing your
vehicle with all four wheels on the ground) and ªdolly
towingº (towing your vehicle with two wheels on the
ground and two wheels up on a device known as
a ªdollyº).
Your vehicle was not designed to be towed with any of
its wheels on the ground. If your vehicle must be towed,
see ªTowing Your Vehicleº in the Index.
NOTICE:
Towing an all-wheel-drive vehicle with all four
wheels on the ground, or even with only two of its
wheels on the ground, will damage drivetrain
components. Don't tow an all
-wheel-drive vehicle
if any of its wheels will be on the ground.
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.

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Towing a Trailer
CAUTION:
If you don't use the correct equipment and drive
properly, you can lose control when you pull a
trailer. For example, if the trailer is too heavy, the
brakes may not work well
-- or even at all. You
and your passengers could be seriously injured.
Pull a trailer only if you have followed all the
steps in this section. Ask your dealer for advice
and information about towing a trailer with
your vehicle.
NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered by
your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer
with your vehicle.
To identify what the vehicle trailering capacity is for
your vehicle, you should read the information in
ªWeight of the Trailerº that appears later in this section.
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.

6-
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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
6
-5 Fuels in Foreign Countries
6
-6 Filling Your Tank
6
-8 Checking Things Under the Hood
6
-11 Engine Oil
6
-17 Engine Air Cleaner/Filter
6
-19 Passenger Compartment Air Filter
6
-20 Automatic Transmission Fluid
6
-23 Rear Axle
6
-24 All-Wheel Drive
6
-27 Engine Coolant
6
-30 Coolant Surge Tank Pressure Cap
6
-31 Power Steering Fluid
6
-32 Windshield Washer Fluid6
-33 Brakes
6
-36 Battery
6
-37 Bulb Replacement
6
-46 Windshield Wiper Blade Replacement
6
-47 Tires
6
-56 Appearance Care
6
-56 Cleaning the Inside of Your Vehicle
6
-60 Cleaning the Outside of Your Vehicle
6
-64 GM Vehicle Care/Appearance Materials
6
-65 Vehicle Identification Number (VIN)
6
-66 Electrical System
6
-76 Replacement Bulbs
6
-76 Capacities and Specifications
6
-77 Normal Maintenance Replacement Parts

6-6
Filling Your Tank
CAUTION:
Gasoline vapor is highly flammable. It burns
violently, and that can cause very bad injuries.
Don't smoke if you're near gasoline or refueling
your vehicle. Keep sparks, flames and smoking
materials away from gasoline.
The fuel cap is located behind a hinged door on the
driver's side of the vehicle.
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).

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CAUTION:
If you get gasoline on yourself and then
something ignites it, you could be badly burned.
Gasoline 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 ªhissº noise to stop. Then unscrew the cap all
the way.
Be careful not to spill gasoline. Clean gasoline from
painted surfaces as soon as possible. See ªCleaning the
Outside of Your Vehicleº in the Index.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 ªMalfunction Indicator Lampº in
the Index.
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 ªMalfunction Indicator
Lampº in the Index.