Hazard Warning Flashers
The hazard warning flashers warn others. They also let
the police and other emergency vehicles know you
have a problem.
The hazard warning
flasher button is
located on top of the
steering column.
Press the button to make the front and rear turn signal
lamps flash on and off. Press the button again to
turn the flashers off.
The hazard warning flashers work no matter what
ignition position the key is in, and even if the key is not
in the ignition.
When the hazard warning flashers are on, your vehicle’s
turn signals will not work.
Other Warning Devices
If you carry reflective triangles, you can set them up at
the side of the road about 300 feet (100 m) behind
your vehicle.
Horn
Sound the horn by pushing the center of the steering
wheel. If you have the optional air horn, it is controlled
by a cord that you will find up above and to the left
of the driver. The harder you pull on the cord, the louder
the air horn will sound. The air horn works only after
your air brake system pressure gets up to about
115 psi (790 kPa). The air horn will work properly
unless the air brake system pressure drops below
60 psi (415 kPa).
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Airbag Readiness Light
If your vehicle has airbags, there is an airbag readiness
light on the instrument panel, which shows the airbag
symbol. The system checks the airbag’s electrical
system for malfunctions. The light tells you if there is an
electrical problem. The system check includes the
airbag sensors, the airbag modules, the wiring, the
passenger airbag suppression circuit and the crash
sensing and diagnostic module. For more information on
the airbag system, seeAirbag 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 airbag readiness light stays on after you start the
vehicle or comes on when you are driving, your
airbag system may not work properly. Have your vehicle
serviced right away.The airbag 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 airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags 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 airbag
readiness light stays on after you start your
vehicle.
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Range Inhibit Warning Indicator
If your vehicle has an Allison 1000/2200/2300/2500 series
automatic transmission, a lighted bar under the current
gear selected will flash.
If your vehicle has an Allison 3000/3500 series
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.
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.
This light should come on briefly when you turn the
ignition key to RUN. If it does not come on, then have it
fixed so it will be ready to warn you if there is a problem.
The brake warning light may come on, and the warning
tone may sound, when you are turning and braking
at the same time. This is normal. See “Hydraulic Brake
Systems” underBraking on page 4-4.
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Parking Brake Warning Light
Your vehicle has a brake warning light. When the
ignition is on, this light will come on when you set your
parking brake. The light will stay on if your parking
brake does not release fully.
This light should also come on when you turn the
ignition key to START. If it does not come on then, have
it fixed so it will be ready to remind you if the parking
brake is applied or has not released fully.
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 is a very
important thing for you to know:
{CAUTION:
If the air brake system 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
air brake system 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.
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Wait to Start Indicator
If your vehicle has the DURAMAX®6.6L diesel engine,
it will have glow plugs and an air intake heater.
If your vehicle has the Isuzu 6H diesel engine, it will
have glow plugs and an inlet heater. If your vehicle has
a Caterpillar
®engine, it will have an inlet heater.
The light in the center of
the instrument panel will
come on when the
inlet heater or glow plugs
are on and the ignition
key is in RUN.
Wait until the indicator light goes off before turning the
ignition key to START.
Malfunction Indicator Lamp
Service Engine Soon Light
If this light comes on or
flashes while you are
driving, two things
can happen.
First, you will not notice any difference in engine
performance, but the tail pipe emissions might increase.
Second, the engine might not run properly or could stall
without warning. If either of these things happen, drive or
tow your vehicle to your dealer/retailer for service.
This light should come on when the ignition is on, but the
engine is not running, as a check to show you it is
working. If it does not come on at all, have it repaired.
Notice:If you keep driving your vehicle with this
light on, after a while, the emission controls
might not work as well, your vehicle’s fuel economy
might not be as good, and the engine might not
run as smoothly. This could lead to costly repairs
that might not be covered by your warranty.
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