2000 GMC SIERRA air condition

iii
Section
3
Comfort Controls and Audio Systems
Section
4
Your Driving and the Road
Section
5
Table of Contents (cont'd)
Braking/Anti-lock Brakes
Steering
Driving Tips for Various Road Conditions
Off-Road DrivingRecreational Vehicle Towing
Loading Your Vehicle
Towing a Trailer Heating and Air Conditioning
Setting the Radio ClockRadio/Cassette Player/CD Player
Radio Theft-Deterrent Feature (If Equipped)
Hazard Warning Flashers
Jump Starting
Towing Your VehicleEngine Overheating
Changing a Flat Tire
If You're Stuck
Problems on the Road

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1-28
When should an air bag inflate?
An air bag is designed to inflate in a moderate to severe
frontal or near
-frontal crash. The air bag will inflate
only if the impact speed is above the system's designed
ªthreshold level.º If your vehicle goes straight into a
wall that doesn't move or deform, the threshold level is
about 9 to 16 mph (14 to 26 km/h). The threshold level
can vary, however, with specific vehicle design, so that
it can be somewhat above or below this range. If your
vehicle strikes something that will move or deform, such
as a parked car, the threshold level will be higher. The
air bag is not designed to inflate in rollovers, side
impacts or rear impacts, because inflation would not
help the occupant.
In any particular crash, no one can say whether an air
bag should have inflated simply because of the damage
to a vehicle or because of what the repair costs were.
Inflation is determined by the angle of the impact and
how quickly the vehicle slows down in frontal or
near
-frontal impacts.
The air bag system is designed to work properly under a
wide range of conditions, including off
-road usage.
Observe safe driving speeds, especially on rough terrain.
As always, wear your safety belt. See ªOff
-Road
Drivingº in the Index for more tips on off
-road driving.What makes an air bag inflate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. The sensing
system triggers a release of gas from the inflator, which
inflates the air bag. The inflator, air bag and related
hardware are all part of the air bag modules inside the
steering wheel and in the instrument panel in front of the
right front passenger.
How does an air bag restrain?
In moderate to severe frontal or near
-frontal collisions,
even belted occupants can contact the steering wheel or
the instrument panel. Air bags supplement the protection
provided by safety belts. Air bags distribute the force of
the impact more evenly over the occupant's upper body,
stopping the occupant more gradually. But air bags
would not help you in many types of collisions,
including rollovers, rear impacts and side impacts,
primarily because an occupant's motion is not toward
those air bags. Air bags should never be regarded as
anything more than a supplement to safety belts,
and then only in moderate to severe frontal or
near
-frontal collisions.

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1-31
This switch should only be turned to AIR BAG OFF if
the person in the right front passenger's position is a
member of a passenger risk group identified by the
national government as follows:
Infant. An infant (less than 1 year old) must ride in the
front seat because:

my vehicle has no rear seat;

my vehicle has a rear seat too small to accommodate
a rear
-facing infant seat; or

the infant has a medical condition which, according
to the infant's physician, makes it necessary for the
infant to ride in the front seat so that the driver can
constantly monitor the child's condition.
Child age 1 to 12.
A child age 1 to 12 must ride in the
front seat because:

my vehicle has no rear seat;

although children ages 1 to 12 ride in the rear
seat(s) whenever possible, children ages 1 to 12
sometimes must ride in the front because no space is
available in the rear seat(s) of my vehicle; or

the child has a medical condition which, according
to the child's physician, makes it necessary for the
child to ride in the front seat so that the driver can
constantly monitor the child's condition.Medical Condition.
A passenger has a medical
condition which, according to his or her physician:

causes the passenger air bag to pose a special risk
for the passenger; and

makes the potential harm from the passenger air bag
in a crash greater than the potential harm from
turning off the air bag and allowing the passenger,
even if belted, to hit the dashboard or windshield in
a crash.
CAUTION:
If the right front passenger's air bag is turned off
for a person who isn't in a risk group identified
by the national government, that person won't
have the extra protection of an air bag. In a
crash, the air bag wouldn't be able to inflate and
help protect the person sitting there. Don't turn
off the passenger's air bag unless the person
sitting there is in a risk group.

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1-34 Adding Equipment to Your Air
Bag-Equipped Vehicle
Q:If I add a push bumper or a bicycle rack to the
front of my vehicle, will it keep the air bags
from working properly?
A:As long as the push bumper or bicycle rack is
attached to your vehicle so that the vehicle's basic
structure isn't changed, it's not likely to keep the
air bags from working properly in a crash.
Q:Is there anything I might add to the front of the
vehicle that could keep the air bags from
working properly?
A:Yes. If you add things that change your vehicle's
frame, bumper system, front end sheet metal or
height, they may keep the air bag system from
working properly. Also, the air bag system may not
work properly if you relocate any of the air bag
sensors. If you have any questions about this, you
should contact Customer Assistance before you
modify your vehicle. (The phone numbers and
addresses for Customer Assistance are in Step Two of
the Customer Satisfaction Procedure in this manual.
See ªCustomer Satisfaction Procedureº in the Index.)
Q:What if I add a snow plow? Will it keep the
air bags from working properly?
A:We've designed our air bag systems to work
properly under a wide range of conditions,
including snow plowing with vehicles equipped
with the optional Snow Plow Prep Package (RPO
VYU). But don't change or defeat the snow plow's
ªtripping mechanism.º If you do, it can damage
your snow plow and your vehicle, and it may cause
an air bag inflation.

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2-75
CAUTION:
If the air bag readiness light ever comes on when
you have turned off the air bag, it means that
something may be wrong with the air bag system.
The right front passenger's air bag could inflate
even though the switch is off.
If your vehicle is a regular cab pickup and this
ever happens, don't let anyone whom the
national government has identified as a member
of a passenger air bag risk group sit in the right
front passenger's position (for example, don't
secure a rear
-facing child restraint in your
vehicle) until you have your vehicle serviced.
If your vehicle is an extended cab pickup and this
ever happens, don't let anyone whom the
national government has identified as a member
of a passenger air bag risk group sit in the right
front passenger's position (for example, don't
secure a rear
-facing child restraint in the right
front passenger's seat) until you have your
vehicle serviced.
Voltmeter
When your engine is not
running, but the ignition is
in RUN, this gage shows
your battery's state of
charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power at
engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.

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2-81
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?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out. A few driving trips should turn the light off.

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2-85
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 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.
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.

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2-88 LOW COOLANT
This message is displayed
when the cooling system is
low on coolant.
The engine may overheat. See ªEngine Coolantº in the
Index and have your vehicle serviced as soon as
you can.
CHECK COOLANT TEMP
This message is displayed
when the cooling system
temperature gets hot.
Check the coolant temperature gage and the coolant
level. See ªEngine Coolantº and ªEngine Coolant
Temperature Gageº in the Index. See ªEngine
Overheatingº in the Index for further information.
ENGINE OVERHEATED
This message is displayed
when the cooling system
temperature gets too hot.
This message will be displayed after the air conditioning
system has automatically turned off for the engine
coolant protection mode. See ªEngine Overheatingº in
the Index for further information.
REDUCED ENGINE POWER
(V8 Engines Only)
This message is displayed
when the cooling system
temperature gets too hot
and the engine further
enters the engine coolant
protection mode.
See ªEngine Overheatingº in the Index for
further information.