1999 GMC SIERRA warning

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How to Use this Manual
Many people read their owner's manual from beginning
to end when they first receive their new vehicle. If you
do this, it will help you learn about the features and
controls for your vehicle. In this manual, you'll find
that pictures and words work together to explain
things quickly.
Index
A good place to look for what you need is the Index in
back of the manual. It's an alphabetical list of what's in
the manual, and the page number where you'll find it.
Safety Warnings and Symbols
You will find a number of safety cautions in this book.
We use a box and the word CAUTION to tell you
about things that could hurt you if you were to ignore
the warning.
CAUTION:
These mean there is something that could hurt
you or other people.
In the caution area, we tell you what the hazard is. Then
we tell you what to do to help avoid or reduce the
hazard. Please read these cautions. If you don't, you or
others could be hurt.

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You will also find a circle
with a slash through it in
this book. This safety
symbol means ªDon't,º
ªDon't do thisº or ªDon't
let this happen.º
Vehicle Damage Warnings
Also, in this book you will find these notices:
NOTICE:
These mean there is something that could
damage your vehicle.
In the notice area, we tell you about something that can
damage your vehicle. Many times, this damage would
not be covered by your warranty, and it could be costly.
But the notice will tell you what to do to help avoid
the damage.
When you read other manuals, you might see
CAUTION and NOTICE warnings in different colors or
in different words.
You'll also see warning labels on your vehicle. They use
the same words, CAUTION or NOTICE.

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For example,
these symbols
are used on an
original battery:
CAUTION
POSSIBLE
INJURY
PROTECT
EYES BY
SHIELDING
CAUSTIC
BATTERY
ACID COULD
CAUSE
BURNS
AVOID
SPARKS OR
FLAMES
SPARK OR
FLAME
COULD
EXPLODE
BATTERY
These symbols
are important
for you and
your passengers
whenever your
vehicle is
driven:
DOOR LOCK
UNLOCK
FASTEN
SEAT
BELTS
POWER
WINDOW
AIR BAG
These symbols
have to do with
your lamps:
MASTER
LIGHTING
SWITCH
TURN
SIGNALS
PARKING
LAMPS
HAZARD
WARNING
FLASHER
DAYTIME
RUNNING
LAMPS
FOG LAMPS
These symbols
are on some of
your controls:
WINDSHIELD
WIPER
WINDSHIELD
WASHER
WINDSHIELD
DEFROSTER
REAR
WINDOW
DEFOGGER
VENTILATING
FAN
These symbols
are used on
warning and
indicator lights:
ENGINE
COOLANT
TEMP
BATTERY
CHARGING
SYSTEM
BRAKE
COOLANT
ENGINE OIL
PRESSURE
ANTI-LOCK
BRAKES
Here are some
other symbols
you may see:
FUSE
LIGHTER
HORN
SPEAKER
FUEL
Vehicle Symbols
These are some of the symbols you may find on your vehicle.

2-
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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 Tailgate
2
-4 Third Door (If Equipped)
2
-5 Door Locks
2
-6 Keyless Entry System (If Equipped)
2
-9 Theft
2
-10 Passlock

2-10 New Vehicle ªBreak-Inº
2
-11 Ignition Positions
2
-13 Starting Your Gasoline Engine
2
-15 Engine Coolant Heater (If Equipped)
2
-16 Automatic Transmission Operation
2
-19 Manual Transmission Operation
2
-21 Four-Wheel Drive (If Equipped)
2
-25 Parking Brake
2
-27 Shifting Into Park (P)
(Automatic Transmission Only)
2
-29 Shifting Out of Park (P)
(Automatic Transmission)2
-30 Parking Your Vehicle
(Manual Transmission Only)
2
-30 Parking Over Things That Burn
2
-31 Engine Exhaust
2
-31 Running Your Engine While You're Parked
(Automatic Transmission)
2
-32 Locking Rear Axle (If Equipped)
2
-32 Windows
2
-35 Tilt Wheel (If Equipped)
2
-35 Turn Signal/Multifunction Lever
2
-41 Exterior Lamps
2
-42 Interior Lamps
2
-44 Mirrors
2
-51 Storage Compartments
2
-60 Instrument Panel
2
-62 Instrument Panel Cluster
2
-64 Warning Lights, Gages and Indicators

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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
with some delay.
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
with some delay.
Shifting from 2HI or 4HI to 4LO
To shift from 2HI or 4HI to 4LO, the vehicle must be
stopped or moving less than 3 mph (4.8 km/h) with the
transmission in NEUTRAL (N). The preferred method
for shifting into 4LO is to have your vehicle moving 1 to
2 mph (1.6 to 3.2 km/h). Press and release the 4LO
switch. You must wait for the 4LO indicator light to stop
flashing and remain illuminated before shifting your
transmission into gear.
If the 4LO switch is pressed when your vehicle is in
gear and/or moving, the 4LO indicator light will flash
for 30 seconds and not complete the shift unless your
vehicle is moving slower than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N). After 30 seconds the
transfer case will return to 4HI.Shifting from 4LO to 4HI or 2HI
To shift from 4LO to 4HI or 2HI, your vehicle must be
stopped or moving less than 3 mph (4.8 km/h) with the
transmission in NEUTRAL (N). The preferred method
for shifting out of 4LO is to have your vehicle moving
1 to 2 mph (1.6 to 3.2 km/h). Press and release the
4HI switch. You must wait for the 4HI indicator light to
stop flashing and remain illuminated before shifting
your transmission into gear.
If the 4HI switch is pressed when your vehicle is in gear
and/or moving, the 4HI indicator light will flash for 30
seconds but will not complete the shift unless the
vehicle is moving slower than 3 mph (4.8 km/h) and the
transmission is in NEUTRAL (N).
Parking Brake
To set the parking brake, hold the regular brake pedal
down with your right foot. Push down the parking brake
pedal with your left foot.
If the ignition is on, the brake system warning light will
come on.
To release the parking brake, hold the regular brake
pedal down.

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Pull the lever, located
just above the parking
brake pedal, marked
BRAKE RELEASE.
If the ignition is on when the parking brake is released,
the brake system warning light will go off.
NOTICE:
Driving with the parking brake on can cause
your rear brakes to overheat. You may have to
replace them, and you could also damage other
parts of your vehicle. Always check to be sure
your parking brake is fully released before
you drive.
If you are towing a trailer and are parking on any hill,
see ªTowing a Trailerº in the Index. That section shows
what to do first to keep the trailer from moving.
If you have a 3500 HD model, it is recommended that
the propshaft
-mounted parking brake be burnished as
part of the new vehicle break
-in. The parking brake
will work best after it has been burnished following
these instructions.
Make 10 stops, using the parking brake foot pedal, from
20 mph (32 km/h) about 2 1/2 miles (4 km) apart. In
between stops, drive the vehicle at 20 mph (32 km/h).

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Warning Lights, Gages and Indicators
This part describes the warning lights and gages that
may be on your vehicle. The pictures will help you
locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause an
expensive repair or replacement. Paying attention to
your warning lights and gages could also save you or
others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle's functions. As you
will see in the details on the next few pages, some
warning lights come on briefly when you start the
engine just to let you know they're working. If you are
familiar with this section, you should not be alarmed
when this happens.
Gages can indicate when there may be or is a problem
with one of your vehicle's functions. Often gages and
warning lights work together to let you know when
there's a problem with your vehicle.When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual's advice.
Waiting to do repairs can be costly
-- and even
dangerous. So please get to know your warning lights
and gages. They're a big help.
Safety Belt Reminder Light
When the key is turned to RUN or START, a tone will
come on for about eight seconds to remind people to
fasten their safety belts, unless the driver's safety belt is
already buckled.
The safety belt light will
also come on and stay on
for about 20 seconds, then
it will flash for about
55 seconds.
If the driver's belt is already buckled, neither the tone
nor the light will come on.

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2-67 Charging System Indicator Light
This light should come on
briefly when you turn on the
ignition, before starting the
engine, as a check to show
you it is working.
After the engine starts, the light should go out. If it stays
on or comes on while you are driving, you may have a
problem with your charging system. It could indicate a
problem with the generator drive belt, or some other
charging system problem. Have it checked right away.
Driving while this light is on could drain your battery.
If you must drive a short distance with this light on, it
helps to turn off all your accessories, such as the radio
and the air conditioner.
Voltmeter
When your engine is not
running, but the ignition is
in RUN, this gage shows
your battery's state of
charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between the
low and high warning zones indicate the normal
operating range.
Readings in the low warning zone may occur when a
large number of electrical accessories are operating in
the vehicle and the engine is left at an idle for an
extended period. This condition is normal since the
charging system is not able to provide full power at
engine idle. As engine speeds are increased, this
condition should correct itself as higher engine speeds
allow the charging system to create maximum power.