1999 GMC YUKON four wheel drive

2-
yellowblue
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
-6 Keyless Entry System
2
-11 Rear Doors
2
-13 Theft
2
-13 Theft-Deterrent System
2
-16 Feature Customization
2
-20 Passlock

2-20 New Vehicle ªBreak-Inº
2
-21 Ignition Positions
2
-22 Starting Your Engine
2
-24 Engine Coolant Heater (If Equipped)
2
-25 Automatic Transmission Operation
2
-28 Four-Wheel Drive
2
-32 Parking Brake
2
-33 Shifting Into Park (P)
2
-35 Shifting Out of Park (P)
2
-36 Parking Over Things That Burn
2
-36 Engine Exhaust2
-37 Running Your Engine While You're Parked
2
-38 Locking Rear Axle
2
-38 Windows
2
-39 Horn
2
-39 Tilt Wheel
2
-40 Multifunction Lever
2
-46 Exterior Lamps
2
-49 Interior Lamps
2
-51 Mirrors
2
-55 Storage Compartments
2
-61 Ashtrays and Cigarette Lighter
2
-63 Sun Visors
2
-63 Universal Transmitter
2
-67 Cellular Telephone (If Equipped)
2
-67 OnStar
System (If Equipped)
2
-68 Instrument Panel
2
-70 Instrument Panel Cluster
2
-72 Warning Lights, Gages and Indicators

yellowblue
2-28
Four-Wheel Drive
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
section that follows before using four
-wheel drive. You
should use 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.
Front Axle Locking Feature
The front axle locks and unlocks automatically when
you shift the transfer case. Some delay for the axle to
lock or unlock is normal.
Automatic Transfer Case

yellowblue
2-29
The transfer case switches are below and to the left of
the climate controls. Use these switches to shift into and
out of four
-wheel drive. You can choose among four
driving settings:
2HI: This setting is used for driving in most situations.
Your front axle is not engaged in two
-wheel drive. This
setting also provides the best fuel economy.
AUTO 4WD: This setting is ideal for use when road
conditions are variable. When driving your vehicle in
AUTO 4WD, the front axle is engaged, but the vehicle'spower is sent only to the rear wheels. When the vehicle
senses a loss of traction, the system will automatically
engage four
-wheel drive. Driving in this mode results in
lower fuel economy than 2HI.
4HI: Use 4HI when you need extra traction, such as on
snowy or icy roads or in most off
-road situations. This
setting also engages your front axle to help drive
your vehicle.
4LO: This setting also engages your front axle and
delivers extra torque. You may never need 4LO. It sends
maximum power to all four wheels. You might choose
4LO if you are driving off
-road in deep sand, deep mud,
deep snow and climbing or descending steep hills.
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). You or someone else could be
seriously injured. Be sure to set the parking
brake before placing the transfer case in
NEUTRAL. See ªParking Brakeº in the Index.

yellowblue
2-33
Shifting Into PARK (P)
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. If
you have 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, use the steps that
follow. With four
-wheel drive if your transfer
case is in NEUTRAL (N), your vehicle will be free
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). If you're pulling a trailer, see
ªTowing a Trailerº in the Index.
1. Hold the brake pedal down with your right foot and
set the parking brake.
2. Move the shift lever into PARK (P) position like this:

Pull the shift lever toward you.

yellowblue
2-34

Move the lever up as far as it will go.
3. Be sure the transfer case is in a drive gear
-- not
in NEUTRAL.
4. Turn the ignition key to LOCK.
5. Remove the key and take it with you. If you can
leave your vehicle with the ignition key in your
hand, your vehicle is in PARK (P).
Leaving Your Vehicle With the
Engine Running
CAUTION:
It can be dangerous to leave your vehicle with the
engine running. Your vehicle could move
suddenly if the shift lever is not fully in PARK (P)
with the parking brake firmly set. With
four
-wheel drive if your transfer case is in
NEUTRAL (N), your vehicle will be free 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). And, if you leave the vehicle with
the engine running, it could overheat and even
catch fire. You or others could be injured. Don't
leave your vehicle with the engine running unless
you have to.

yellowblue
2-37
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 air system control 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.

yellowblue
2-80 Security Light
This light will come on
briefly when you turn the
key to 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 GM dealer.
Service Four-Wheel Drive Warning Light
Your vehicle is equipped with an 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.
If the SERVICE 4WD light comes on, there may be a
problem with the Automatic 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.

4-
yellowblue
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
-28 Driving at Night4
-30 Driving in Rain and on Wet Roads
4
-33 City Driving
4
-34 Freeway Driving
4
-35 Before Leaving on a Long Trip
4
-36 Highway Hypnosis
4
-36 Hill and Mountain Roads
4
-38 Winter Driving
4
-42 Recreational Vehicle Towing
4
-43 Loading Your Vehicle
4
-45 Towing a Trailer