1999 GMC SONOMA wheel

2-24 Electronic Transfer Case (If Equipped)
If your four-wheel-drive
vehicle has the electronic
transfer case, the transfer
case switches are located
to the right of the
steering wheel.
Use these switches 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 switches 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 switch. This can be done at
any speed, and the front axle will lock automatically.
Shifting from 4HI to 2HI
Press and release the 2HI switch. This can be done at
any speed, and the front axle will unlock automatically.

2-32
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).
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.
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.
Windows
Manual Windows
Turn the hand crank on each door to raise or lower your
manual side door windows.
Power Windows (If Equipped)
If you have the optional power windows, the controls
are on each of the side doors. With power windows, the
switches control the windows when the ignition is on, in
ACCESSORY, or when Retained Accessory Power
(RAP) is present. (See ªRetained Accessory Powerº in
the Index.) The driver's door has a switch for the
passenger window as well.

2-34 Sliding Rear Window (If Equipped)
Squeeze the latch in the center of the window and slide
the glass to open it.
When you close the window, be sure the latch catches.
Horn
Press the steering wheel pad to sound the horn.
Tilt Wheel (If Equipped)
If you have the tilt steering
wheel, you should adjust
the steering wheel before
you drive.
You can raise it to the highest level to give your legs
more room when you enter and exit the vehicle.
To tilt the wheel, hold the steering wheel and pull the
lever toward you. Move the steering wheel to a
comfortable level, then release the lever to lock the
wheel in place.
Do not adjust the steering wheel while driving.

2-38 Cruise Control (If Equipped)
With cruise control, you can
maintain a speed of about
25 mph (40 km/h) or more
without keeping your foot
on the accelerator. This can
really help on long trips.
Cruise control does not
work at speeds below about
25 mph (40 km/h).
If you have an automatic transmission and you apply
your brakes, the cruise control will shut off.
If you have a manual transmission and you apply your
brakes or push the clutch pedal, the cruise control will
shut off.CAUTION:

Cruise control can be dangerous where you
can't drive safely at a steady speed. So,
don't use your cruise control on winding
roads or in heavy traffic.

Cruise control can be dangerous on
slippery roads. On such roads, fast changes
in tire traction can cause needless wheel
spinning, and you could lose control. Don't
use cruise control on slippery roads.

2-44
Interior Lamps
Brightness Control
Turn the thumbwheel next to the headlamp switch up to
make your instrument panel lights brighter. Turn the
thumbwheel all the way up to turn on the interior lamps.
Illuminated Entry
Your vehicle is equipped with an illuminated entry feature.
When the doors are opened, the dome lamps will come
on if the DOME OVERRIDE button is in the ªoutº
position. If your vehicle is equipped with remote keyless
entry and all the doors are closed, or the front door
handles are lifted and released, the lamps will stay on
for a short period of time and will turn off automatically.
If you use your keyless entry transmitter to unlock the
vehicle, the interior lights will come on for a short time
whether or not the DOME OVERRIDE button is in
the ªoutº position.
Exit Lighting
With exit lighting, the interior lamps will come on when
you remove the key from the ignition to help you seewhile exiting the vehicle. These lights will stay on for a
short period of time and then will go out, if the DOME
OVERRIDE button is in the ªoutº position.
Front Map Lamps (If Equipped)
If your vehicle has front map lamps, they are located
on the inside rearview mirror. They will automatically
come on for approximately 40 seconds when the
doors are unlocked with the keyless entry transmitter
(if equipped) or until the ignition key is turned to
RUN or ACCESSORY. The lamps will also stay on
for approximately 40 seconds after you exit the
vehicle, unless you lock the doors with the keyless
entry transmitter.
You can also turn the lamps on and off by pressing the
switch near each lamp.
Dome Lamps
The dome lamps will come on when you open the doors.
You can also turn the dome lamps on by turning the
thumbwheel, located next to the parking/headlamps
knob, all the way up to the top detent position.
In this position, the dome lamps will remain on
whether the doors are opened or closed.

2-65 Security Warning Light
This light will come on
briefly when you turn the
key toward START. The
light will stay on until the
engine starts.
If the light flashes, the Passlock

system has entered a
tamper mode. If the vehicle fails to start, see ªPasslockº
in the Index.
If the light comes on continuously while driving and
stays on, there may be a problem with the Passlock
system. Your vehicle will not be protected by Passlock,
and you should see your dealer.
Also see ªContent Theft
-Deterrentº in the Index for
additional information regarding the SECURITY light.
Service Four-Wheel-Drive Warning Light
If your vehicle is equipped with the Automatic
Four
-Wheel-Drive Transfer Case, it has a computer
which controls the four
-wheel-drive system.
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.

3-5 Defogging and Defrosting
On cool, humid days, use BLEND to keep the
windshield and side windows clear.
Use DEFROST to remove fog or ice from the
windshield quickly in extreme humid or cold conditions.
Turn the temperature knob clockwise and turn the fan
control toward high.
If you have the heated outside mirror feature, you can
use it to defog or defrost your outside mirrors. For more
information, see ªHeated Outside Mirrorsº in the Index.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use VENT to direct outside air
through your vehicle. Airflow is through the instrument
panel outlets.
Your vehicle's ventilation system supplies outside air to
the inside of your vehicle when it is moving. When the
vehicle is not moving, you can get outside air to flow
through by selecting any mode and any fan speed.
You will find air outlets in the center and on the sides of
your instrument panel.
You can direct the airflow side
-to-side by moving the
thumbwheel located in the center of the vent. The vent
can be tilted up and down also. To control the amount
of airflow through the outlets, move the thumbwheel
below the vent.

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
-11 Passing
4
-13 Loss of Control
4
-14 Off-Road Driving with Your
Four
-Wheel-Drive Vehicle
4
-26 Driving at Night4
-28 Driving in Rain and on Wet Roads
4
-31 City Driving
4
-32 Freeway Driving
4
-33 Before Leaving on a Long Trip
4
-34 Highway Hypnosis
4
-34 Hill and Mountain Roads
4
-36 Winter Driving
4
-39 Recreational Vehicle Towing
4
-40 Loading Your Vehicle
4
-45 Pickup Conversion to Chassis Cab
4
-46 Towing a Trailer