Page 21 of 272

WARNING LIGHTS AND CHIMES
Warning lights and gauges can alert you to a vehicle condition that may
become serious enough to cause expensive repairs. A warning light may
illuminate when a problem exists with one of your vehicle’s functions.
Many lights will illuminate when you start your vehicle to make sure the
bulb works. If any light remains on after starting the vehicle, have the
respective system inspected immediately.
Service engine soon:If this light
illuminates while driving, it is a
possible indication that one of the
engine’s emission control systems
has failed.
Check suspension (if equipped):
Illuminates when there is a fault in
the electronic subsystem of the air
suspension.
Stop engine (if equipped):This
light is used in conjunction with the
electronic engine control.
Refer to the Engine Operator’s Manual for specific information regarding
this feature.
If the engine shuts down, it can be restarted and operated for 30
seconds at a time or until the problem is corrected. Refer toEngine
shutdown systemin theDrivingchapter.
Drivers of electronically controlled engines should know the
extent of warning engine shutdown system before operating the
vehicle. This information can be obtained from your dealer.
SERVICE
ENGINE
SOON
STOP
ENGINE
Instrumentation
Instrumentation
21
Page 22 of 272

Brake reserve system warning
(if equipped):Illuminates to
indicate normal Hydromax booster
reserve system activation when the
engine is OFF and the service brake
pedal is applied.
This light may also illuminate momentarily if the engine is running and
the driver turns the steering wheel fully in one direction while braking.
If the light remains on while the engine is running, this indicates
inadequate hydraulic booster pressure or reserve pump system failure.
Stop the vehicle safely as soon as possible and seek service immediately.
Brake system warning light:To
confirm the brake system warning
light is functional, this light will
momentarily illuminate when the
ignition is turned to the ON position when the engine is not running. If
the brake system warning light does not illuminate at this time, seek
service immediately from your dealership. Illumination after starting the
vehicle indicates a pressure differential in the master cylinder and the
brake system should be inspected immediately by your dealership.
If equipped with an air brake system, the warning light stays on until the
air pressure builds up to 60 psi (414 kPa). If the air pressure drops
below 60 psi (414 kPa) during operation, the remaining brake system is
still operational but the stopping distance will be greater.
Driving a vehicle with the brake system warning light on is
dangerous. A significant decrease in braking performance may
occur. It will take you longer to stop the vehicle. Have the vehicle
checked by your dealer immediately.
Anti-lock brake system:If the
ABS light stays illuminated or
continues to flash, a malfunction has
been detected, have the system
serviced immediately. Normal
braking is still functional unless the brake warning light also is
illuminated.
BRAKE
ABS
Instrumentation
22
Page 23 of 272

Trailer ABS brake system (if
equipped):Illuminates briefly when
the engine is powered-up and only
when a PLC trailer or a PLC
diagnostic tool is connected. If the
light remains on after the vehicle is started, continues to flash or fails to
illuminate, have the system serviced immediately.
Parking brake warning:
Momentarily illuminates when the
ignition is turned to the ON position
and the engine is off. Also
illuminates when the parking brake
is engaged. If the brake warning
lamp does not illuminate at these
times, seek service immediately.
Vehicles equipped with the Power Park (air-operated parking
brake) option:If after setting the parking brake on your vehicle the
park brake warning lamp begins to blink, this may indicate a failure in
the parking brake system. Seek service from your dealer immeadiately.
Safety belt:Reminds you to fasten
your safety belt. A chime will also
sound to remind you to fasten your
safety belt.
Check trans (Allison automatic
transmission):The lamp will
illuminate for several seconds after
the ignition is turned to the ON
position. Illumination of this light indicates that a problem has been
detected and shifting may be restricted. Depending upon the severity of
the problem, the read-out digit on the shifter display may be blank.
Operation may continue in order to reach service assistance. The ECU
may not respond to shift selector requests, since operating limitations
are being placed on the transmission, i.e. upshifts and downshifts may be
restricted. Direction changes will not occur.
Refer to the Transmission Operator’s Manual for more information.
P
BRAKE
CHECK
TRANS
Instrumentation
23
Page 24 of 272

Range inhibit:Illuminates when
the transmission is not engaged in
the selected gear. The warning light
will go off when the gearshift lever
is adjusted in to the appropriate gear.
Refer to the Transmission Operator’s Manual for more information.
Charging system:Illuminates when
the battery is not charging properly.
Wait to start:Indicates the air
intake heater is in operation and
special starting procedures are
required. Refer to theDriving
chapter.
If equipped with an air intake heater, DO NOT use ether or any
other starting fluids. The use of starting fluids (ether) in an
engine equipped with an air intake heater could result in damage
and/or personal injury.
Water in fuel (if equipped):
During refueling it is possible for
water-contaminated diesel fuel to be
pumped into your fuel tank. Your
vehicle fuel system is equipped with
a fuel filter/water separator to remove water from the fuel. The indicator
light illuminates when the fuel filter/water separator has a significant
quantity of water, or when the ignition key is switched to the START
position. If the light illuminates when the engine is running, stop the
vehicle as soon as safely possible, shut off the engine and drain the filter
bowl. Allowing water to stay in the system could result in extensive
damage to, or failure of, the fuel injection system.
To drain the fuel filter/water separator (refer toMaintenance and
Specificationschapter for procedure), rotate the valve at the bottom of
the filter assembly allowing water to drain from the system. Close the
valve upon completion.
RANGE
INHIBIT
WAIT
TO
START
WATER
IN
FUEL
Instrumentation
24
Page 25 of 272
Do not drain water separator while engine is running. Fuel may
ignite if separator is drained while engine is running or vehicle is
moving.
Traction control (if equipped):
Illuminates when the traction
control system is turned off.
Differential lock (if equipped):
Illuminates when the main
differential is locked (engaged).
Turn signal:Illuminates when the
left or right turn signal or the
hazard lights are turned on. If the
indicators stay on or flash faster, check for a burned out bulb.
High beams:Illuminates when the
high beam headlamps are turned on.
Key-in-ignition warning chime:Sounds when the key is left in the
ignition in the OFF/LOCK or ACC position and the driver’s door is
opened.
Headlamps on warning chime:Sounds when the headlamps or parking
lamps are on, the ignition is off (and the key is not in the ignition) and
the driver’s door is opened.
Instrumentation
25
Page 29 of 272

Fuel gauge:Indicates
approximately how much fuel is left
in the fuel tank (when the ignition
is in the on position). If your vehicle
is equipped with dual fuel tanks, the
engine will draw fuel from the
passenger-side fuel tank only. With
dual fuel tanks, the vehicle will be
equipped with a fuel transfer pump system that will draw fuel from the
driver-side fuel tank and send fuel to the passenger-side fuel tank. The
passenger-side fuel tank must have fuel in it at all times otherwise the
vehicle may stall and may be difficult to re-start. The fuel gauge reads
the fuel level only from the passenger-side fuel tank.
Air pressure gauge (if equipped):
All vehicles equipped with air brakes
have a dual-pointer air gauge to
indicate the pressure in each brake
circuit. The green pointer indicates
the air pressure in the primary
system and the red pointer indicates
the air pressure in the secondary
system. When the pressure is too low
for normal brake operation (less than
60 psi [414 kPa]) and the ignition is
on:
•a warning buzzer will sound and
•a warning light will illuminate in the instrument cluster
Vehicles equipped with hydraulic brakes and an air compressor have a
single-pointer air gauge.
Note:This system doesnothave a low air pressure warning buzzer or a
low air pressure warning light.
Do not drive the vehicle when the low air pressure buzzer is
sounding or the warning light is lit. These warnings indicate
there is not enough air pressure for the brake or suspension system to
operate properly.
0 30120 90 60
150AIR
PRESSURE
PSI
Instrumentation
29
Page 49 of 272
INTERIOR LAMPS
Map lamps (if equipped)
To turn on the map lamps, press the
control next to each lamp.
EXTERIOR BULBS
Checking operation of lamps, safety equipment and warning
signals
It is a good safety practice to check operation of headlamps, parking
lamps, turn signals, clearance and marker lamps, instrument panel and
control lamps each day.
Using the right bulbs
Function Number of
bulbsTrade number
Headlamps 2 4652
Front turn signal lamps 2 1157
Front sidemarker/Park lamps 2 (amber) 194
Brake/Tail/Stop/Rear turn
signal/License lamps4 2057
Back-up lamps 2 1156
Front clearance and identification
lamps5 168
Dome lamp 1 105
To replace all instrument panel lights - see your dealer
Lights
49
Page 74 of 272

To lower the shoulder belt height, push the button and slide the height
adjuster down. To raise the height of the shoulder belt, slide the height
adjuster up. Pull down on the height adjuster to make sure it is locked in
place.
Position the safety belt height adjusters so that the belt rests
across the middle of your shoulder. Failure to adjust the safety
belt properly could reduce the effectiveness of the seat belt and
increase the risk of injury in a collision.
Lap belts
The front center and rear center lap belts do not adjust automatically.
The lap belt should fit snugly and as low as possible around the
hips, not across the waist.
Insert the tongue into the correct
buckle (the buckle closest to the
direction the tongue is coming
from). To lengthen the belt, turn the
tongue at a right angle to the belt
and pull across your lap until it
reaches the buckle. To tighten the
belt, pull the loose end of the belt
through the tongue until it fits snugly across the hips.
Shorten and fasten the belt when
not in use.
Safety belt warning light and indicator chime
The safety belt warning light illuminates in the instrument cluster and a
chime sounds to remind the occupants to fasten their safety belts.
Seating and safety restraints
74