4 wheel drive control GMC SUBURBAN 1999 Owner's Manual

Table of Contents
Keys and Door Locks
Keyless Entry System (If Equipped)
Liftgate
Automatic Transmission Operation
Four-Wheel Drive (If Equipped)
Parking Brake
Windows
Tilt Wheel (If Equipped)
Turn Signal/Multifunction Lever
Windshield Wipers
Cruise ControlInterior and Exterior Lamps
Mirrors
Storage Compartments
Convenience Net/Cargo Cover/Luggage Carrier (If Equipped)
Accessory Power Outlets
OnStar® System (If Equipped)
Sunroof (If Equipped)
HomeLink® Transmitter (If Equipped)
Instrument Panel, Warning Lights and Gages
Message Center Seats and Seat Controls
Safety BeltsAir Bag Systems
Child Restraints
Section
1
Section
2
Seats and Restraint Systems
Features and Controls
ii

2-
2-1
Section 2 Features and Controls
Here you can learn about the many standard and optional features on your vehicle, and information on starting,
shifting and braking. Also explained are the instrument panel and the warning systems that tell you if everything is
working properly
-- and what to do if you have a problem.
2
-2 Keys
2
-3 Door Locks
2
-7 Keyless Entry System (If Equipped)
2
-11 Theft
2
-12 Content Theft-Deterrent (If Equipped)
2
-13 Passlock

2-14 New Vehicle ªBreak Inº
2
-14 Ignition Positions
2
-15 Starting Your Engine
2
-17 Engine Coolant Heater (If Equipped)
2
-18 Automatic Transmission Operation
2
-22 Four-Wheel Drive (If Equipped)
2
-27 Parking Brake
2
-28 Shifting Into PARK (P)
2
-30 Shifting Out of PARK (P)
2
-31 Parking Over Things That Burn
2
-31 Engine Exhaust2
-32 Running Your Engine While You're Parked
2
-33 Level Control (If Equipped)
2
-34 Autoride (If Equipped)
2
-34 Locking Rear Axle
2
-34 Windows
2
-36 Turn Signal/Multifunction Lever
2
-43 Exterior Lamps
2
-46 Interior Lamps
2
-48 Mirrors
2
-55 Storage Compartments
2
-62 HomeLink
Transmitter (If Equipped)
2
-65 OnStar
System (If Equipped)
2
-66 The Instrument Panel - Your
Information System
2
-68 Instrument Panel Cluster
2
-69 Warning Lights, Gages and Indicators
2
-82 Message Center

2-20
To rock your vehicle back and forth to get out of snow,
ice or sand without damaging your transmission, see
ªStuck: In Sand, Mud, Ice or Snowº in the Index.
NEUTRAL (N): In this position, your engine doesn't
connect with the wheels. To restart when you're already
moving, use NEUTRAL (N) only. Also, use NEUTRAL (N)
when your two
-wheel drive vehicle is being towed.
CAUTION:
Shifting out of PARK (P) or NEUTRAL (N) while
your engine is ªracingº (running at high speed)
is dangerous. Unless your foot is firmly on the
brake pedal, your vehicle could move very
rapidly. You could lose control and hit people
or objects. Don't shift out of PARK (P) or
NEUTRAL (N) while your engine is racing.
NOTICE:
Damage to your transmission caused by shifting
out of PARK (P) or NEUTRAL (N) with the
engine racing isn't covered by your warranty.
DRIVE (D): This position is for normal driving. If you
need more power for passing, and you're:

Going less than about 35 mph (56 km/h), push your
accelerator pedal about halfway down.

Going about 35 mph (56 km/h) or more, push the
accelerator all the way down.
You'll shift down to the next gear and have more power.
DRIVE (D) can be used when towing a trailer, carrying
a heavy load, driving on steep hills or for off
-road
driving. You may want to shift the transmission to
THIRD (3) or, if necessary, a lower gear selection if
the transmission shifts too often.

2-21
THIRD (3): This position is also used for normal
driving, however it offers more power and lower fuel
economy than DRIVE (D).
SECOND (2): This position gives you more power but
lower fuel economy. You can use SECOND (2) on hills.
It can help control your speed as you go down steep
mountain roads, but then you would also want to use
your brakes off and on.
If you manually select SECOND (2) in a light duty
automatic transmission, the transmission will drive in
second gear. You may use this feature for reducing the
speed of the rear wheels when you are trying to start
your vehicle from a stop on slippery road surfaces.
FIRST (1): This position gives you even more power
(but lower fuel economy) than SECOND (2). You can
use it on very steep hills, or in deep snow or mud. If the
selector lever is put in FIRST (1) while the vehicle is
moving forward, the transmission won't shift into first
gear until the vehicle is going slowly enough.
NOTICE:
If your rear wheels can't rotate, don't try to
drive. This might happen if you were stuck in
very deep sand or mud or were up against a solid
object. You could damage your transmission.
Also, if you stop when going uphill, don't hold
your vehicle there with only the accelerator
pedal. This could overheat and damage the
transmission. Use your brakes or shift into
PARK (P) to hold your vehicle in position
on a hill.
On cold days, approximately 32
F (0
C) or colder,
your transmission is designed to shift differently until
the engine reaches normal operating temperature.
This is intended to improve heater performance.

2-32
Running Your Engine While
You're Parked
It's better not to park with the engine running. But if
ever you have to, here are some things to know.
CAUTION:
Idling the engine with the climate control
system off could allow dangerous exhaust into
your vehicle (see the earlier Caution under
ªEngine Exhaustº).
Also, idling in a closed-in place can let deadly
carbon monoxide (CO) into your vehicle even if
the fan switch is at the highest setting. One place
this can happen is a garage. Exhaust
-- with
CO
-- can come in easily. NEVER park in a
garage with the engine running.
Another closed-in place can be a blizzard.
(See ªBlizzardº in the Index.)
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 (N) 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 (N). 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.

2-40 Cruise Control
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 apply your brakes, the cruise control will disengage.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.

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 Traction Assist System (Option)
4
-11 Steering
4
-13 Off-Road Recovery
4
-14 Passing
4
-15 Loss of Control
4
-16 Off-Road Driving with Your
Four
-Wheel-Drive Vehicle4
-31 Driving at Night
4
-32 Driving in Rain and on Wet Roads
4
-35 City Driving
4
-36 Freeway Driving
4
-37 Before Leaving on a Long Trip
4
-38 Highway Hypnosis
4
-38 Hill and Mountain Roads
4
-40 Winter Driving
4
-44 Recreational Vehicle Towing
4
-46 Loading Your Vehicle
4
-51 Towing a Trailer

4-8
Here's how anti-lock works. Let's say the road is wet.
You're driving safely. Suddenly an animal jumps out in
front of you.
You slam on the brakes. Here's what happens with ABS.
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at
both rear wheels.The anti
-lock system can change the brake pressure faster
than any driver could. The computer is programmed to
make the most of available tire and road conditions.
You can steer around the obstacle while braking hard.
As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.

4-10
If your vehicle is in cruise control when the TAS begins
to limit wheel spin, the cruise control will automatically
disengage. When road conditions allow you to safely
use it again, you may turn the cruise control back on.
See ªCruise Controlº in the Index.
When the TRACTION OFF
light is on, the TAS is off
and will not limit wheel
spin. Adjust your
driving accordingly.
The TRACTION OFF light will come on under the
following conditions:

The Traction Assist System is turned off, either by
pressing the TAS on/off button or turning off the
automatic engagement feature of the TAS.

The transmission is in FIRST (1); TAS will not
operate in this gear. This is normal.

The vehicle is driven on a severely rough road.
When the vehicle leaves the rough surface, slows
down or stops, the light will go off and TAS will be
on again. This is normal.

A Traction Assist System problem has been detected
and the vehicle needs service.See ªTraction Off Lightº in the Index.
The Traction Assist System, as delivered from the
factory, will automatically come on whenever you start
your vehicle. To limit wheel spin, especially in slippery
road conditions, you should always leave the system on.
But you can turn the TAS off if you ever need to.
(You should turn the TAS off if your vehicle ever gets
stuck in sand, mud, ice or snow. See ªRocking Your
Vehicleº in the Index.)
To turn the system on or off
press the TAS on/off button
located to the left of the
steering wheel on the
instrument panel.
If you used the button to turn the system off, the
TRACTION OFF light will come on and stay on. You
can turn the system back on at any time by pressing the
button again. The TRACTION OFF light should go off.

4-11
If desired, you can change the TAS automatic
engagement feature so that the system will not come
on automatically when the engine is started. To do so:
1. Park vehicle with ignition off and transmission
in PARK (P).
2. Turn the ignition to RUN; do not start the engine.
3. Apply the brake pedal, press the accelerator pedal to
the floor and then press the TAS on/off button and
hold it down for at least six seconds.
4. Release the TAS button and both pedals.
5. Turn off the ignition and wait a few seconds.
The next time you start your vehicle, the TAS will not
automatically come on. You can restore the automatic
feature by using the same procedure. Whether the
TAS is set to come on automatically or not, you can
always turn the system on or off by pressing the TAS
on/off button.Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer
but it will take much more effort.
Steering Tips
Driving on Curves
It's important to take curves at a reasonable speed.
A lot of the ªdriver lost controlº accidents mentioned
on the news happen on curves. Here's why:
Experienced driver or beginner, each of us is subject
to the same laws of physics when driving on curves.
The traction of the tires against the road surface makes it
possible for the vehicle to change its path when you turn
the front wheels. If there's no traction, inertia will keep
the vehicle going in the same direction. If you've ever
tried to steer a vehicle on wet ice, you'll understand this.
The traction you can get in a curve depends on the
condition of your tires and the road surface, the angle at
which the curve is banked, and your speed. While you're
in a curve, speed is the one factor you can control.