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Tachometer
This gage shows the engine speed in revolutions per
minute (rpm).
Safety Belt Reminder Light
When the key is turned to RUN or START, a light will
come on for several seconds to remind people to fasten
their safety belts.
The safety belt light will
also come on and stay on
for several seconds.
Safety Belt Reminder Tone
If your vehicle has this feature, when you turn your key
to RUN or START, a tone will sound for several
seconds to remind people to fasten their safety belts. 7.2L Caterpillar
®Diesel
Engine and 7.8L
DURAMAX™ Diesel
EnginesGasoline and 6.6L
DURAMAX™ Diesel
Engines
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Air Bag Readiness Light
If your vehicle has air bags, there is an air bag readiness
light on the instrument panel, which shows the airbag
symbol. 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 modules, the wiring, the
passenger air bag suppression circuit and the crash
sensing and diagnostic module. For more information on
the air bag system, seeAir Bag System on page 1-48.
This light will come on
when you start your
vehicle, 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
vehicle 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 or
START. If the light doesn’t come on then, have it fixed
so it will be ready to warn you if there is a problem.
{CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not in ate in a crash, or they
could even in ate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the air bag
readiness light stays on after you start
your vehicle.
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Air Bag Off Light
If your vehicle is equipped with an air bag off switch,
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. SeeAir Bag
Off Switch on page 1-55for more on this, including
important safety information.
United States
Canada
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{CAUTION:
If the right front passenger’s air bag is turned
off for a person who isn’t in a risk group
identi ed by the national government, that
person won’t have the extra protection of an
air bag. In a crash, the air bag wouldn’t be able
to in ate and help protect the person sitting
there. Don’t turn off the passenger’s air bag
unless the person sitting there is in a risk
group. See″Air Bag Off Switch″in the Index
for more on this, including important safety
information.
{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 in ate even though the switch is off. If
this ever happens, don’t let anyone whom the
national government has identi ed as a
member of a passenger air bag risk group sit
in the right front passenger’s position (for
example, don’t secure a rear-facing child
restraint in the right front passenger’s seat)
until you have your vehicle serviced.
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Charging System Light
The charging system light
may be located in the
instrument panel cluster, or
with the auxiliary warning
lights in the center of
the instrument panel.
It should come on briefly when you turn on the ignition,
before the engine is running, as a check to show
that it is working.
If it stays on, or comes on while you are driving, have
your vehicle checked right away. You could have a loose
generator drive belt or some other problem.
Driving while this light is on will drain your battery. If you
must drive a short distance with the light on, turn off
your radio and other accessories. Sustained driving with
a generator failure could result in a lack of back-up
braking if the engine quits or the power steering pump
should fail.
Voltmeter Gage
When your engine is
running, the voltmeter
gage shows the charging
system voltage.
Readings in either warning zone indicate a possible
problem in the electrical system.
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 may not be able to provide full power
at engine idle. As engine speeds are increased,
this condition should correct itself because higher
engine speeds allow the charging system to create
maximum power.
You can only drive a short time on the battery. Be sure
to shut off the radio, the fan or any unnecessary
accessories and have the system serviced.
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Service Transmission Warning Light
If your vehicle has an Allison automatic transmission,
certain transmission malfunctions will turn this light on.
This light is located with
the auxiliary warning lights
in the center of the
instrument panel.
If this light comes on while you are driving, do not use
the transmission shift control or you may lose forward
gears. The computer for the transmission senses
a problem and chooses a gear to stay in so that you
can drive the vehicle in that gear. You may not be able
to drive as fast or back up when this light is on.
Notice:If you continue driving your vehicle after
the transmission warning light comes on, you could
damage the transmission. While this light is on,
the transmission cannot operate in all gears. If you
attempt to shift gears, the vehicle may not
continue to move. Do not attempt to shift gears
while the transmission warning light is on. Instead,
drive directly to a GM dealer for service. If you
cannot drive to a dealer immediately, have the
vehicle towed.
Range Inhibit Warning Indicator
If your vehicle has an Allison
1000/2000/2200/2400 series automatic transmission, a
lighted bar under the current gear selected will flash.
If your vehicle has an Allison MD automatic
transmission, the current gear selected on the
pushbutton display will flash.
The flashing bar or gear selection indicates that
transmission range shifts may not occur.
For detailed information on shift inhibit limitations, see
the Allison Automatic Transmission Operator’s Manual in
your vehicle for further information.
Brake System Warning Light
Your vehicle has either hydraulic or air brakes. Each
system has different warning lights.
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Hydraulic Brake System
Warning Lights
Vehicles with hydraulic brake systems have two brake
system warning lights on the instrument panel.
If the BRAKE warning light
comes on, it means that
the fluid level in the master
cylinder reservoir is low
or there is another problem
with your hydraulic
brakes.
When it comes on, you will also hear a warning tone.
The BRAKE warning light may come on, and the
warning tone may sound, when you’re turning and
braking at the same time. This is normal. SeeHydraulic
Brake SystemsunderBraking on page 4-6.If the service brakes soon
warning light comes on, it
means there is something
wrong in the brake
system.
When this light comes on, you will also hear a warning
tone. If this light comes on, have the system repaired
immediately.
Both of these lights should come on briefly every time
you start your engine. If they don’t come on then,
have them fixed so they will be ready to warn you if
there’s a problem. If one or both of these warning lights
stay on after you start the engine, there could be a
brake problem. Have your brake system inspected
right away.
If one or both of these lights come 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 BRAKE light is still on, have the vehicle
towed for service. SeeTowing Your Vehicle on
page 4-31. SeeHydraulic Brake SystemsunderBraking
on page 4-6for further information.
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Air Brake System Warning Light
Vehicles with air brake systems have a brake system
warning light on the instrument panel.
The LOW AIR warning light should come on, as a
check, whenever you start the engine. However, it is
designed to come on, and stay on, when brake reservoir
pressure has dropped below 60 psi (410 kPa).
When the warning light comes on while you are driving,
you should drive only as far as the nearest point of
safety and then stop the vehicle. Here’s a very important
thing for you to know:{CAUTION:
If the LOW AIR warning light comes on and the
warning tone sounds, the vehicle can stop
suddenly and without further warning. This is
because the parking brake will come on if
the pressure falls below 35 to 45 psi (240 to
310 kPa). You or others could be injured. If the
LOW AIR warning light comes on and the
warning tone sounds, stop as soon as you
can. You will not know how quickly the system
is losing pressure, so be aware that the
parking brake may come on suddenly. United States
Canada
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