1998 GMC SIERRA light

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
miiy 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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Air Bag Readiness Light
There is an air bag readiness light on the instrument panel,
which shows AIR BAG. The system checks
the air bag’s
electrical system for malfunctions. The light tells
you if
there is an electrical problem. The system check includes
the air bag sensors, the air bag module, the wiring and the
diagnostic module. For more information
on the air bag
system, see “Air Bag”
in the Index,
~
AIR
BAG
This light will come on
when you start your engine,
and
it will flash for a few
seconds. Then the light
should go out. This means
the system is ready.
If the air bag readiness light stays on after you start the
engine or comes on when
you are driving, your air bag
system may not work properly. Have your vehicle
serviced right away.
The air bag readiness light should flash for a few
seconds when
you turn the ignition key to RUN. If the
light doesn’t come
on then, have it fixed so it will be
ready to warn you
if there is a problem.
AIR BAG OFF Light (Except Crew Cab)
When you turn the right front passenger’s air bag off, this
light will come
on and stay on to remind you that the air
bag has been turned off. This light will go off when you
turn the air bag back on again. See “Securing a Child
Restraint in the Right Front Seat Position”
in the Index for
more on this, including important safety information.
-
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If the right front passenger’s air bag is turned
off, an adult or
a child who is no longer an infant
sitting in the right front passenger’s position
won’t have the extra protection of an air bag. In
a crash, the air bag wouldn’t be able to inflate
and help protect the person sitting there. Make
sure the air bag is turned on unless you are using
a rear-facing child restraint in the right front
seat position.
A
A CAUTION:
If the air bag readiness light ever comes on when
you have turned off the air bag, it means that
something may be wrong with the air bag system.
The right front passenger’s air bag could inflate
even though the switch is off.
If this ever
happens, don’t secure a rear-facing child
restraint in your vehicle until you have your
vehicle serviced.
Charging System Indicator Light
7-1 This light should come on
I-+I
brieflywhen you turn on the
ignition, before starting the
engine,
as a check to show
you it is working.
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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
19
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.
You can only drive for a short time with the reading in
either warning zone. If you must drive, turn off all
unnecessary accessories.
Readings in either warning zone indicate a possible
problem in the electrical system. Have the vehicle
serviced as soon as possible.
Brake System Warning Light
When the ignition is on, the brake system warning light
will come on when you set your parking brake. The light
will stay on
if your parking brake doesn’t release fully.
If it stays on after your parking brake is fully released, it
means you have a brake problem.
Your vehicle’s hydraulic brake system is divided into
two parts. If one part isn’t working, the other part can
still work and stop you. For good braking, though,
you
need both parts working well.
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If the warning light comes on, there co11ld be a brake
problem. Have your brake system inspected right away.
This light should come on
(a) (@)
briefly when you turn the
ignition key
to RUN. If it
doesn‘t come on then, have
it
fixed so it will be ready to
warn you if there’s a problem. BRAKE
If the light comes on while you are driving, pull off the
road and
stop carefully. You may notice that the pedal is
harder
to push. Or, the pedal may go closer to the floor.
It may take longer to stop.
If the light is still on, have the
vehicle towed
for service. (See “Towing Your Vehicle”
in the Index.)
Your brake system may not be working properly
if the brake system warning light is
on. Driving
with the brake system warning light on can lead
to an accident.
If the light is still on after you’ve
pulled off the road and stopped carefully, have
the vehicle towed for service.
Anti-Lock Brake System Warning Light
With the anti-lock brake
system,
this light will
come on when you start
ANTI -
LOCK
your engine and may stay
on for several seconds.
That’s normal.
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If the light stays on, or comes on when you’re driving,
your vehicle needs service.
If the regular brake system
warning light isn’t on, you still have brakes, but you
don’t have anti-lock brakes.
If the regular brake system
warning light is also on, you don’t have anti-lock brakes
and there‘s a problem
with your regular brakes. See
“Brake System Warning Light” earlier
in this section.
The anti-lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If the
light doesn‘t come on then. have it fixed
so it will be
ready to warn you
if there is a problem.
Engine Coolant Temperature Gage
1
This gage shows the engine
coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority of the operation, the gage
will read
210°F (100°C) or less. If you are pulling a
load or going up hills, it is normal for the temperature to
fluctuate and approach the
260°F (1 25 “C) mark. If the
gage reaches the
260°F (125°C) mark, it indicates that
the cooling system is working beyond its capacity.
The “Problems on
the Road,” section of this manual shows
what
to do. See “Engine Overheating” in the Index.
Malfunction Indicator Lamp (Service
Engine
Soon Light) (Gasoline Engine)
SERVICE
ENGINE
SOON
Your vehicle is equipped
with a computer which
monitors operation
of the
fuel, ignition and emission
control systems.
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This system is called OBD I1 (On-Board
Diagnostics-Second Generation) and is intended to
assure that emissions are at acceptable levels for the life
of the vehicle, helping to produce a cleaner
environment. The
SERVICE ENGINE SOON light
comes on to indicate that there is a problem and service
is required. Malfunctions often will be indicated by the
system before any problem is apparent. This may
prevent more serious damage to your vehicle. This
system is also designed to assist your service technician
in correctly diagnosing any malfunction.
~OTICE:
If you keep driving your vehicle with this light
on, after a while, your emission controls may not
work as well, your fuel economy may not be as
good and your engine may not run as smoothly.
This could lead to costly repairs that may not be
covered by your warranty.
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn’t come on, have it repaired.
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This light will also come on during a malfunction in one
of two ways:
0 Light Flashing -- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.
0 Light On Steady -- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.
If the Light Is Flashing
The following may prevent’more serious aamage to
your vehicle:
Reducing vehicle speed.
Avoiding hard accelerations.
0 Avoiding steep uphill grades.
0 If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.
If the light stops flashing
and remains on steady, see “If
the Light Is On Steady” following.
If the light continues
to flash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
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Turn the key off, wait at least 10 seconds and restart the
engine.
If the light remains on steady, see “If the Light
Is On Steady” following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center
for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently
put fuel into your vehicle?
If
so, reinstall the fuel cap, making sure to fully install
the cap. The diagnostic system can determine if the fuel
cap has been left off or improperly installed.
A loose or
missing fuel cap will allow fuel to evaporate into the
atmosphere.
A few driving trips with the cap properly
installed should turn the light
off.
Did you just drive through a deep puddle of water‘?
If so, your electrical system may be wet. The condition
will usually be corrected when the electrical system
dries out.
A few driving trips should turn the light off.
Are you low on fuel? As
your engine starts to run
out of fuel, your engine may
not run
as efficiently as designed since small amounts of
air are sucked into the fuel line causing
a misfire. The
system can detect this. Adding fuel should correct this
condition. Make sure to install the
fuel cap properly. It
will take
a few driving trips to turn the light off.
Have you recently changed brands of fuel?
If
so, be sure to fuel your vehicle with quality fuel (see
“Fuel”
in the Index). Poor fuel quality will cause your
engine not to run
as efficiently as designed. You may
notice this as stalling after start-up, st.alling
when you
put the vehicle into gear, misfiring, hesitation on
acceleration or stumbling on acceleration. (These
conditions may go away once the engine is warmed up.)
This will be detected by the system and cause the light
to turn on.
If
you experience one or more of these conditions,
change the fuel brand
you use. It will require at least one
full tank of the proper fuel to turn the light off.
If none of the above steps have made the light turn off,
have your dealer or qualified service center check the
vehicle. Your dealer has the proper test equipment and
diagnostic
tools to fix any mechanical or electrical
problems that may have developed.
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