2002 GMC SONOMA four wheel drive

2-31 Shift Speeds
CAUTION:
If you skip a gear when you downshift, you could
lose control of your vehicle. You could injure
yourself or others. Don't shift down more than
one gear at a time when you downshift.
If your vehicle has four-wheel drive and is equipped
with a manual transmission, disregard the SHIFT light
when the transfer case is in 4LO.
Four-Wheel Drive (If Equipped)
If your vehicle has four-wheel drive, you can send your
engine's driving power to all four wheels for extra
traction. To get the most satisfaction out of four
-wheel
drive, you must be familiar with its operation. Read the
part that follows before using four
-wheel drive. You
should use two
-wheel high (2HI) for most normal
driving conditions.
NOTICE:
Driving in the 4HI or 4LO positions for a long
time on dry or wet pavement could shorten the
life of your vehicle's drivetrain.

2-32 Electronic Transfer Case (If Equipped)
The electronic transfer case
buttons are located to the
right of the steering wheel.
Use these buttons to shift into and out of four
-wheel
drive. You can choose among three driving settings:
2HI: This setting is for driving in most street and
highway situations. Your front axle is not engaged in
two
-wheel drive. When this lamp is lit, it is about
one
-half as bright as the others.4HI: This setting engages your front axle to help drive
your vehicle. Use 4HI when you need extra traction,
such as on snowy or icy roads, or in most off
-road
situations.
4LO: This setting also engages your front axle to give
you extra traction. You may never need 4LO. It sends
the maximum power to all four wheels. You might
choose 4LO if you were driving off
-road in sand, mud
or deep snow and climbing or descending steep hills.
Indicator lights in the buttons show you which setting
you are in. The indicator lights will come on briefly
when you turn on the ignition and one will stay on.
If the lights do not come on, you should take your
vehicle in for service. An indicator light will flash while
shifting. It will remain illuminated when the shift is
completed.
Shifting from 2HI to 4HI
Press and release the 4HI button. This can be done at
any speed, and the front axle will lock automatically.
Shifting from 4HI to 2HI
Press and release the 2HI button. This can be done at
any speed, and the front axle will unlock automatically.

2-81 Service Four-Wheel-Drive Warning Light
This light should come on
briefly when you turn on the
ignition, as a check to show
you it is working.
The SERVICE 4WD light comes on to indicate that
there may be a problem with the four
-wheel drive
system and service is required. Malfunctions can be
indicated by the system before any problem is apparent,
which may prevent serious damage to the vehicle. This
system is also designed to assist your service technician
in correctly diagnosing a malfunction.
Check Gages Light
If this light comes on and
stays on while you are
driving, check your coolant
temperature and engine oil
pressure gages to see if they
are in the warning zones.

4-
4-1
Section 4 Your Driving and the Road
Here you'll find information about driving on different kinds of roads and in varying weather conditions. We've also
included many other useful tips on driving.
4
-2 Defensive Driving
4
-3 Drunken Driving
4
-6 Control of a Vehicle
4
-6 Braking
4
-9 Steering
4
-11 Off-Road Recovery
4
-12 Passing
4
-13 Loss of Control
4
-14 Off-Road Driving with Your
Four
-Wheel-Drive Vehicle
4
-27 Driving at Night4
-29 Driving in Rain and on Wet Roads
4
-32 City Driving
4
-33 Freeway Driving
4
-34 Before Leaving on a Long Trip
4
-35 Highway Hypnosis
4
-35 Hill and Mountain Roads
4
-37 Winter Driving
4
-41 Recreational Vehicle Towing
4
-45 Loading Your Vehicle
4
-50 Pickup Conversion to Chassis Cab
4
-50 Towing a Trailer

4-14
If your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want the
vehicle to go. If you start steering quickly enough, your
vehicle may straighten out. Always be ready for a
second skid if it occurs.
Of course, traction is reduced when water, snow, ice,
gravel or other material is on the road. For safety, you'll
want to slow down and adjust your driving to these
conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface with reduced traction, try
your best to avoid sudden steering, acceleration or
braking (including engine braking by shifting to a
lower gear). Any sudden changes could cause the tires to
slide. You may not realize the surface is slippery until
your vehicle is skidding. Learn to recognize warning
clues
-- such as enough water, ice or packed snow on
the road to make a ªmirrored surfaceº
-- and slow down
when you have any doubt.
Remember: Any anti
-lock brake system (ABS) helps
avoid only the braking skid.
Off-Road Driving with Your
Four
-Wheel-Drive Vehicle
This off-road guide is for vehicles that have
four
-wheel drive.
Also, see ªAnti
-Lock Brakesº in the Index.
If your vehicle doesn't have four
-wheel drive, you
shouldn't drive off
-road unless you're on a level, solid
surface.
Off
-road driving can be great fun. But it does have some
definite hazards. The greatest of these is the terrain
itself.
ªOff
-roadingº means you've left the great North
American road system behind. Traffic lanes aren't
marked. Curves aren't banked. There are no road signs.
Surfaces can be slippery, rough, uphill or downhill. In
short, you've gone right back to nature.
Off
-road driving involves some new skills. And that's
why it's very important that you read this guide. You'll
find many driving tips and suggestions. These will help
make your off
-road driving safer and more enjoyable.

4-15 Before You Go Off-Roading
There are some things to do before you go out.
For example, be sure to have all necessary maintenance
and service work done. Check to make sure all
underbody shields (if so equipped) are properly
attached. Be sure you read all the information about
your four
-wheel-drive vehicle in this manual. Is there
enough fuel? Is the spare tire fully inflated? Are the
fluid levels up where they should be? What are the local
laws that apply to off
-roading where you'll be driving?
If you don't know, you should check with law
enforcement people in the area. Will you be on
someone's private land? If so, be sure to get the
necessary permission.
Loading Your Vehicle for Off-Road Driving
There are some important things to remember about
how to load your vehicle.

The heaviest things should be on the load floor and
forward of your rear axle. Put heavier items as far
forward as you can.

Be sure the load is secured properly, so driving on
the off
-road terrain doesn't toss things around.
CAUTION:

Cargo on the load floor piled higher than
the seatbacks can be thrown forward
during a sudden stop. You or your
passengers could be injured. Keep cargo
below the top of the seatbacks.

Unsecured cargo on the load floor can be
tossed about when driving over rough
terrain. You or your passengers can be
struck by flying objects. Secure the cargo
properly.

Heavy loads on the roof raise the vehicle's
center of gravity, making it more likely to
roll over. You can be seriously or fatally
injured if the vehicle rolls over. Put heavy
loads inside the cargo area, not on the roof.
Keep cargo in the cargo area as far forward
and low as possible.
You'll find other important information in this manual.
See ªVehicle Loading,º ªLuggage Carrierº and ªTiresº
in the Index.

4-42 Dinghy Towing
(Two-Wheel Drive Models Only)
Your vehicle should not be towed with all four wheels
on the ground. Your transmission has no provision for
internal lubrication while being towed. To properly tow
your vehicle, it should be placed on a platform trailer
with all four wheels off the ground. Towing with all four
wheels on the ground should be avoided.
In rare cases when it's unavoidable and your vehicle
must be towed with all four wheels on the ground, the
propeller shaft to axle yoke orientation should be
marked and the propeller shaft removed following the
applicable service manual removal/installation
procedure. See ªService and Owner Publicationsº in
the Index.
Dust or dirt can enter the back of the transmission
through the opening created by removing the propeller
shaft if proper protection is not provided. Also, check
the transmission fluid level before driving the vehicle.

4-43
When towing your vehicle, turn the ignition to OFF. To
prevent your battery from draining while towing,
remove the RDO BATT and CLSTR fuses from the
instrument panel fuse block. Be sure to replace the fuse
when you reach your destination. See ªFuses and Circuit
Breakersº in the Index.
Be sure to use the proper towing equipment designed for
recreational vehicle towing. Follow the instructions for
the towing equipment.
CAUTION:
Shifting a four-wheel-drive vehicle's transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in Park (P), for an
automatic transmission, or if your vehicle is in
gear, for a manual transmission. You or others
could be injured. Make sure the parking brake is
firmly set before you shift the transfer case to
NEUTRAL.
Dolly Towing
(Two-Wheel Drive Models Only)
Your vehicle should not be towed with all four wheels
on the ground. Your transmission has no provision for
internal lubrication while being towed. To properly tow
your vehicle, it should be placed on a platform trailer
with all four wheels off the ground. Towing with all four
wheels on the ground should be avoided.