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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 system
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 system warning light may come on, and the
warning tone may sound, when you’re turning and
braking at the same time. This is normal. See “Hydraulic
Brake Systems” underBraking on page 4-6.
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If the service brakes soon
warning light comes on, it
means there may be
something wrong in the
brake system.
When this light comes on, you will also hear a warning
tone. 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 4-37. See
“Hydraulic Brake Systems” underBraking on page 4-6
for further information.Parking Brake Warning Light
This light will also come on when you set the parking
brake. The light will stay on if your parking brake
does not release 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).
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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 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.
Anti-Lock Brake System
Warning Light
This light will come on
briefly when you start your
engine, then it will turn
off. This is normal.
If the light stays on, or comes on when you are driving,
your vehicle needs service. If the BRAKE or LOW
AIR warning light is not on, you still have brakes, but
you do not have the anti-lock brake feature. If the
BRAKE and/or LOW AIR warning light is on, you do not
have anti-lock brakes and there is a problem with
your regular brakes. SeeBrake System Warning Light
on page 3-33andAnti-Lock Brake System (ABS)
on page 4-8for more information.
The anti-lock brake system warning light should come
on briefly when you turn the ignition key to ON. If
the light does not come on then, have it fixed so it will
be ready to warn you if there is a problem.
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Trailer Anti-Lock Brake System
Warning Light
If your vehicle is connected
to a trailer with anti-lock
brakes, this light should
come on briefly, as a
check, when you turn on
the ignition.
When this light comes on and stays on, it means there
is something wrong in the trailer anti-lock brake
system. Have the system repaired immediately.
If an anti-lock brake system equipped trailer is not
connected, this light is not functional.
Engine Coolant Temperature Gage
This gage shows the engine coolant temperature. If the
gage pointer moves into the red area, your engine
coolant might have overheated and your engine may be
too hot. You should pull off the road, stop your vehicle
and turn off the engine as soon as possible.
SeeEngine Overheating on page 5-40. If you have a
Caterpillar
®diesel engine, also see your Caterpillar®
Operation & Maintenance Manual.
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Low Coolant Warning Light
You have a low coolant
warning light. If this light
comes on, your system is
low on coolant and the
engine may overheat.
The warning light should come on briefly, as a check,
when you turn on the ignition.
When it comes on, you will also hear a warning tone at
several beats per second for 10 seconds. SeeEngine
Coolant (Gas and DURAMAX
®Engines) on page 5-38
orEngine Coolant (Caterpillar®Diesel Engines) on
page 5-40and have your vehicle serviced as soon as
you can.
This light may also come on if your vehicle is equipped
with the automatic engine shutdown system and
engine shutdown has begun. SeeEngine Alarm and
Automatic ShutdownunderStarting the Diesel Engine
on page 2-15.
Wait to Start Indicator
(Diesel Engine)
If your vehicle has the DURAMAX®6.6L diesel engine,
you will have glow plugs and an air intake heater. If
your vehicle has the DURAMAX
®7.8L diesel engine,
you will have glow plugs and an inlet heater. If your
vehicle has a Caterpillar
®engine, you 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 turns off before turning the
ignition key to START.
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Malfunction Indicator Lamp
Service Engine Soon Light
If this light comes on or
flashes while you are
driving, two things may
happen.
First, you will not notice any difference in engine
performance, but your tail pipe emissions may increase.
Second, your engine may not run properly or may
stall without warning. If either of these things happen,
drive or tow your vehicle to your dealer 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 awhile, 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.
Oil Pressure Gage
The engine oil pressure gage, on the lower right portion
of your instrument panel cluster, shows engine oil
pressure in psi (pounds per square inch) or in kPa
(kilopascals). Oil pressure may vary with outside
temperature and oil viscosity, but readings of
30 to 40 psi (205 to 275 kPa) on gasoline engines at
operating temperature and moderate road speeds
are normal. If you have a diesel engine, the normal
operating range should be between 35 and 70 psi
(240 to 480 kPa).
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A reading in the low pressure zone may be caused by a
dangerously low oil level or other problem.
If you have a Caterpillar
®diesel engine, also see your
Caterpillar®Operation & Maintenance Manual.
{CAUTION:
Do not keep driving if the oil pressure is low. If
you do, your engine can become so hot that it
catches re. You or others could be burned.
Check your oil as soon as possible and have
your vehicle serviced.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
Low Oil Level Light
This light should come on
as a check, when you start
your engine. If the light
fails to come on, have it
repaired as soon as
possible so you will be
aware when the oil level
is low.
Vehicles equipped with Caterpillar
®diesel engines may
not have a low oil level light. In this case, the light
will neither come on as a check when you start your
engine, nor will it come on to indicate a low oil level.
If this light comes on and stays on, it means your engine
is low on oil. You need to check the oil level right
away. SeeEngine Oil (Caterpillar
®Diesel Engine) on
page 5-24orEngine Oil (DURAMAX®Diesel) on
page 5-24orEngine Oil (Gasoline Engine) on page 5-28
for further information.
Notice:Lack of proper engine oil maintenance may
damage the engine. The repairs would not be
covered by your warranty. Always follow the
maintenance schedule in this manual for changing
engine oil.
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Change Engine Oil Light
The change engine oil light
should come on briefly as
a bulb check when you
start the engine. If the light
does not come on, have
it serviced.
If the change engine oil light comes on and stays on
after you start the engine, have the oil changed.
For additional information on when to change engine oil
for gasoline engines or DURAMAX
®diesel engines,
seeEngine Oil (Caterpillar®Diesel Engine) on page 5-24
orEngine Oil (DURAMAX®Diesel) on page 5-24or
Engine Oil (Gasoline Engine) on page 5-28and
Scheduled Maintenance on page 6-5. To reset the
change engine oil light, seeEngine Oil Life System
(Gasoline Engine) on page 5-31orEngine Oil Life
System (DURAMAX
®Diesel) on page 5-33orEngine
Oil Life System (Caterpillar®Diesel Engine) on
page 5-34.
Engine Overspeed Warning Light
If your vehicle has this
light, it will come on if your
engine is operating at
too many revolutions
per minute (rpm).
It will also come on for a moment as a check when you
start your engine.
If it comes on when you’re driving, reduce your engine
speed immediately.
Engine Shutdown Warning Light
If your vehicle has the
engine shutdown feature,
this light will come on
when engine shutdown is
active.
For more information, seeEngine Alarm and Automatic
ShutdownunderStarting the Diesel Engine on
page 2-15.
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