1999 GMC C-SERIES 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.
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
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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.
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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
-4 Door Locks
2
-5 Theft
2
-5 New Vehicle ªBreak-Inº
2
-6 Ignition Positions
2
-7 Starting Your Gasoline Engine
2
-10 Starting Your Diesel Engine
2
-13 Engine Checks Before Operating
2
-15 Engine Coolant Heater (If Equipped)
2
-16 Diesel Engine Exhaust Brake
2
-17 Two-Speed Rear Axle Electric Shift Control
(If Equipped)
2
-20 Automatic Transmission Operation
2
-22 Manual Transmission Operation
2
-23 Parking
2
-29 Parking Over Things That Burn
2
-29 Engine Exhaust2
-30 Running Your Engine While You're Parked
(Automatic Transmission)
2
-30 Windows
2
-31 Tilt Wheel (If Equipped)
2
-32 Turn Signal/Multifunction Lever
2
-39 Trailer Brake Hand Control Valve (Option)
2
-40 Inter-Axle Differential Lock Control
(If Equipped)
2
-41 Rear Axle Differential Lock Control
(If Equipped)
2
-42 Engine Air Control (If Equipped)
2
-43 Exterior Lamps
2
-46 Interior Lamps
2
-46 Mirrors
2
-50 Instrument Panel
2
-52 Instrument Panel Cluster
2
-55 Warning Lights, Gages and Indicators
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2-11 Cold Weather Starting (Caterpillar

Diesel)
Because the diesel engine uses compression ignition, it
is harder to start in cold weather than a gasoline engine.
The air intake heater and use of the proper engine oil,
optional engine coolant heaters and optional ether
injection systems help cold weather starting. See the
Caterpillar

Operation & Maintenance Manual for
more information.
Diesel Engine Warm-Up
Several factors affect how quickly your diesel engine
warms up. These can include outside temperature,
engine load, idle time and your vehicle's option content.
Your vehicle may be equipped with some features that
can help the engine reach operating temperature sooner.
Some of these features are discussed below.
Also, remember that an automatic transmission adds
heat to the cooling system through the heat exchanger in
the radiator. Because of this, vehicles equipped with
automatic transmissions are often able to retain engine
coolant heat better than manual transmission vehicles.
See your Caterpillar

Operation & Maintenance manual
for additional diesel engine warm
-up information.
Engine Automatic Shutdown (If Equipped)
Your CHECK GAGES light will come on if the system
senses high engine temperature or low engine oil
pressure. If high engine temperature is detected, you
will also hear a tone alarm at two beats per second. The
alarm and the light will remain on until the condition is
fixed. If the engine temperature condition worsens, the
tone alarm will go to five beats per second. When a low
oil pressure condition is detected, the five beat per
second alarm will come on immediately.
If the system senses low engine coolant, the five beat
per second alarm and the LOW COOLANT warning
light will come on.
The five beats per second tone alarm means that your
engine will shut down in 25 seconds. Pull off the road
and shut off the engine. Don't start it until the reason for
the problem is known, and the problem is fixed. If the
engine shuts down when you are still in traffic, you can
restart the engine and get another 25 seconds of
operation. Do this only if you have to, since there is a
problem that can harm the engine if it isn't fixed.
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2-13
The manual fast idle feature is activated by pressing the
switch on the instrument panel. When the switch is
pressed again, or any of the previous conditions are not
met, manual fast idle will be deactivated.
Manual fast idle can be used to set any desired idle
speed. To set a new temporary engine idle speed:
1. Make sure all of the previously described conditions
are met.
2. Press the accelerator pedal to the desired engine speed.
3. Momentarily press the manual FAST IDLE switch.
The temporary idle speed will be set. This new rpm
level will be remembered by the system until either the
ignition is turned to OFF or a new idle speed is set.
Radiator Shutters -- Caterpillar

(If Equipped)
Radiator shutters aid engine warm-up by blocking the
airflow through the radiator and charge the air cooler to
conserve heat in cold conditions.
The radiator shutters on your vehicle (if equipped)
operate automatically. When the ignition switch is in
RUN or START and the engine temperature is below
195F (90C), the shutters will close, blocking the flow
of air through the radiator and charge the air cooler.When the engine temperature reaches 195F (90C), the
shutters will open to the normal operating position.
Engine Checks Before Operating
When you've started your engine, let it run for 20 to
30 seconds before you put a load on the engine.
But don't leave the vehicle while the engine is running.
During this warm
-up period, check your warning lights
and gages:

If oil pressure doesn't begin to rise within 15 seconds
of starting, stop the engine and find the cause.

If the engine coolant temperature gage needle goes
into the hot area on the gage, stop the engine and
find the cause of the overheating.

If you have air brakes, the dual
-needle air pressure
gage should read at least 105 psi (720 kPa) for both
service systems before you try to move the vehicle.
When air pressure is below 60 psi (420 kPa), the
LOW AIR light will come on and you will hear a
tone alarm. If the pressure doesn't build up or drops
during warm
-up, stop the engine and find the cause
before you try to move the vehicle. Recommended
air pressure before actually driving away is
120 psi (830 kPa).
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2-33 Turn Signal and Lane Change Indicator
The turn signal has two upward (for right) and two
downward (for left) positions. These positions allow you
to signal a turn or a lane change.
To signal a turn, move the lever all the way up or down.
When the turn is finished, the lever will return automatically.
An arrow on the instrument
cluster will flash in the
direction of the turn or
lane change.
To signal a lane change, just raise or lower the lever
until the arrow starts to flash. Hold it there until you
complete your lane change. The lever will return by
itself when you release it.
As you signal a turn or a lane change, if the arrows don't flash
but just stay on, check the turn signal flasher and circuit
breaker. See ªFuses and Circuit Breakersº in the Index.
If a bulb is burned out, replace it to help avoid an
accident. If the arrows don't go on at all when you
signal a turn, check the circuit breaker and for
burned
-out bulbs. (See ªFuses and Circuit Breakersº in
the Index.)
Signal-Stat Turn Signal and Hazard
Warning Flasher (If Equipped)
If you have this signal system, it is mounted beside or
behind the multifunction lever on the left side of the
steering column.
To signal a turn, move the lever all the way up or down.
When the turn is completed, move the lever back to the
center position.
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2-34
An arrow on the instrument panel will flash in the
direction of the turn when the lever is in the up or
down position.
This system replaces the turn signal feature of the
multifunction lever only. All other features such as
headlamp high/low beam, windshield wipers and
washer, etc. remain part of the multifunction system.
If you have this system, see ªSignal
-Stat Turn Signal
and Hazard Warning Flasherº in the Index to find out
how the hazard warning flasher portion works.
Headlamp High/Low Beam Changer
To change the headlamps from low beam to high, push
the multifunction lever away from you. To switch back
to low beam, pull the lever toward you.
When the high beams are
on, a light on the instrument
cluster will also be on.
Windshield Wipers
The windshield wipers are controlled by turning the
band with the wiper symbol on it.
For a single wiping cycle, turn the band to MIST. Hold
it there until the wipers start, then let go. The wipers will
stop after one cycle. If you want more cycles, hold the
band on MIST longer.
For steady wiping at low speed, turn the band away
from you to the LO position. For fast wiping, turn the
band to HI. To stop the wipers, turn the band to the
off symbol.
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