2001 GMC YUKON air condition

Table of Contents (cont'd)
Your Driving, the Road and Your Vehicle
Defensive Driving
Drunken Driving
Control of a Vehicle
Braking
SteeringDriving Tips for Various Road Conditions
Off-Road Driving
Recreational 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
Section
5
Section
4
Section
3
Comfort Controls and Audio Systems
Your Driving and the Road
iii

1-33
When should an air bag inflate?
The driver's and right front passenger's frontal air bags
are designed to inflate in moderate to severe frontal or
near
-frontal crashes. But they are designed to 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 driver's and right front passenger's frontal
air bags are not designed to inflate in rollovers, side
impacts, or rear impacts, because inflation would not
help the occupant.
The side impact air bags are designed to inflate in
moderate to severe side crashes. A side impact air bag
will inflate if the crash severity is above the system's
designed ªthreshold level.º The threshold level can vary
with specific vehicle design. Side impact air bags are not
designed to inflate in frontal or near
-frontal impacts,
rollovers or rear impacts, because inflation would not
help the occupant. A side impact air bag will only
deploy on the side of the vehicle that is struck.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. For
frontal air bags, inflation is determined by the angle of
the impact and how quickly the vehicle slows down in
frontal and near
-frontal impacts. For side impact air
bags, inflation is determined by the location and severity
of the impact.
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. For both
frontal and side impact air bags, 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, instrument panel and the side of the front
seatbacks closest to the door.

1-37
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.
Lap Belt
If your vehicle has front and rear bench seats, someone
can sit in the center positions.
When you sit in a center seating position, you have a lap
safety belt, which has no retractor. To make the belt
longer, tilt the latch plate and pull it along the belt.

2-34
CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
Don't leave your vehicle when the engine is
running unless you have to. If you've left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
Four-wheel drive vehicles with the transfer case
in NEUTRAL will allow the vehicle to roll, even if
your shift lever is in PARK (P). So, be sure the
transfer case is in a drive gear
-- not in
NEUTRAL. Always set your parking brake.
Follow the proper steps to be sure your vehicle won't
move. See ªShifting Into PARK (P)º in the Index.
If you're pulling a trailer, see ªTowing a Trailerº in
the Index.
Level Control (If Equipped)
Self-Adjusting
The self
-adjusting rear suspension is available on
C/K 1500 vehicles and is available with the premium
smooth ride suspension package.
This type of level control will provide a leveled riding
position as well as improved handling under a variety of
passenger and loading conditions. A hydraulic pump
inside each rear shock absorber raises the rear of the
vehicle to the proper height, based on inputs from
the road surface, while the vehicle is being driven.
It takes approximately 2 miles (3.2 km) of driving
for the leveling to complete, depending on the road
surface conditions.
If the loaded vehicle is not moved for approximately
twelve hours, the leveling system may bleed down to a
lower height. This can be especially apparent if a trailer
is left attached to a parked vehicle for long periods of
time. The vehicle must be driven to re
-level the vehicle.
If a self
-equalizing hitch is being used, the vehicle
should be driven approximately 2 miles (3.2 km) with
the trailer prior to adjusting (leveling) the hitch.

2-35
Automatic Level Control
The automatic level control rear suspension is available
on C/K 1500 vehicles and comes as a part of the
Autoride
suspension.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected to the rear
shocks will raise or lower the rear of the vehicle to
maintain proper vehicle height. The system is activated
when the ignition key is turned to RUN and will
automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for
up to ten minutes after the ignition key has been
turned to OFF. You may hear the air compressor
operating when the height is being adjusted.
If a self
-equalizing hitch is being used, it is
recommended to allow the shocks to inflate, thereby
leveling the vehicle prior to adjusting the hitch.
Autoride
(If Equipped)
The Autoride
feature will provide a superior vehicle
ride and handling under a variety of passenger and
loading conditions.The system is fully automatic and uses a computer
controller to continuously monitor vehicle speed, wheel
to body position, lift/drive and steering position of the
vehicle. The controller then sends signals to each shock
absorber to independently adjust the damping level to
provide the optimum vehicle ride.
Autoride also interacts with the tow/haul switch that,
when engaged, will provide additional control of the
shock absorbers. This additional control results in
better ride and handling characteristics when the vehicle
is loaded or towing a trailer. See ªTow/Haul Modeº in
the Index for more information.
Locking Rear Axle
If your vehicle has this feature, your locking rear axle
can give you additional traction on snow, mud, ice, sand
or gravel. It works like a standard axle most of the time,
but when one of the rear wheels has no traction and the
other does, this feature will allow the wheel with
traction to move the vehicle.

2-76
The following situations can cause the transmission to
operate at higher temperatures:

Towing a trailer

Hot outside air temperatures

Hauling a large or heavy load

Low transmission fluid level

High transmission fluid level

Restricted air flow to the radiator and the auxiliary
transmission oil cooler (if equipped).
A temporary solution to hotter transmission operating
temperatures may be to let the transmission cool down.
If the transmission is operated at higher temperatures on
a frequent basis, see ªScheduled Maintenanceº in the
Index for the proper transmission maintenance intervals.Low Traction Light (If Equipped)
If you have the Traction
Assist System, this light
will come on when the
system is limiting wheel
spin. See ªTraction Assist
Systemº in the Index.
You may feel or hear the system working or notice a
lack of accelerator response, but this is normal.
The LOW TRACTION light also comes on briefly when
you turn your ignition to RUN. If the light doesn't come
on then, the system may require service; have it fixed so
it will be there to tell you when the Traction Assist
System is active. Slippery road conditions may exist if
the LOW TRACTION light comes on, so adjust your
driving accordingly.

2-79
NOTICE:
Modifications made to the engine, transmission,
exhaust or fuel system of your vehicle or the
replacement of the original tires with other
than those of the same Tire Performance
Criteria (TPC) can affect your vehicle's emission
controls and may cause the SERVICE ENGINE
SOON or CHECK ENGINE light to come on.
Modifications to these systems could lead to
costly repairs not covered by your warranty. This
may also result in a failure to pass a required
Emission Inspection/Maintenance test.
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.

2-85 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.
Trans Fluid Hot
If you have an automatic transmission, you have a
transmission temperature warning display contained in
the message center.
If the transmission fluid
temperature becomes high,
the message center will
display this message.
When the transmission enters the protection mode, you
may notice a change in the transmission shifting
patterns. When the transmission fluid temperature
returns to normal, the display will turn off and the
transmission shifting patterns will return to normal.
NOTICE:
If you keep driving your vehicle with the
transmission TRANS FLUID HOT message
displayed, you can damage the transmission.
This could lead to costly repairs that may not be
covered under your warranty.