Periodic Safety Checks You Should Make Outside
The Vehicle
Tires
Examine tires for excessive tread wear and uneven wear
patterns. Check for stones, nails, glass, or other objects
lodged in the tread or sidewall. Inspect the tread for cuts
and cracks. Inspect sidewalls for cuts, cracks and bulges.
Check the wheel nuts for tightness. Check the tires
(including spare) for proper cold inflation pressure.
Lights
Have someone observe the operation of brake lights and
exterior lights while you work the controls. Check turn
signal and high beam indicator lights on the instrument
panel.
Door Latches
Check for positive closing, latching, and locking.
Fluid Leaks
Check area under vehicle after overnight parking for fuel,
engine coolant, oil, or other fluid leaks. Also, if gasoline
fumes are detected or if fuel, power steering fluid
(2500,3500,4500,5500 Models Only), or brake fluid leaks
are suspected, the cause should be located and corrected
immediately.
124 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE
until a check-mark appears next to setting, showing that
setting has been selected. Touch the back arrow soft-key
to return to the previous menu.
•Rain Sensing Auto Wipers
When this feature is selected, the system will automati-
cally activate the windshield wipers if it senses moisture
on the windshield. To make your selection, touch the
Rain Sensing soft-key, until a check-mark appears next to
setting, showing that setting has been selected. Touch the
back arrow soft-key to return to the previous menu.
• Hill Start Assist — If Equipped
When this feature is selected, the Hill Start Assist (HSA)
system is active. Refer to “Electronic Brake Control
System” in “Starting And Operating” for system function
and operating information. To make your selection, touch
the Hill Start Assist soft-key, until a check-mark appears next to setting, showing that setting has been selected.
Touch the back arrow soft-key to return to the previous
menu.
•
Four Corner Air Suspension Modes — If Equipped
There are four air suspension modes designed to protect
the system in unique situations. Tire Jack Mode is se-
lected to assist in changing a spare tire. Transport Mode
is selected to assist when the vehicle is being flat bed
towed. Wheel Alignment Mode is selected before per-
forming a wheel alignment, refer to your authorized
dealer for information. Protection Mode will automati-
cally be selected in order to “protect” the air suspension
system when the payload has been exceeded or load
leveling cannot be achieved.
Lights
After pressing the Lights soft-key the following settings
will be available.
302 UNDERSTANDING YOUR INSTRUMENT PANEL
▫Snow Tires ......................... .494
▫ Spare Tire Matching Original Equipped Tire And
Wheel – If Equipped ...................495
▫ Compact Spare Tire – If Equipped .........495
▫ Full Size Spare – If Equipped .............496
▫ Limited-Use Spare – If Equipped ..........496
▫ Tire Spinning ....................... .497
▫ Tread Wear Indicators ..................497
▫ Life Of Tire ........................ .498
▫ Replacement Tires .....................499
SUPPLEMENTAL TIRE PRESSURE INFORMATION
— IF EQUIPPED ...................... .500
TIRE CHAINS ........................ .501
TIRE ROTATION RECOMMENDATIONS .....503▫
Directional Tires – If Equipped ............504
▫ Dual Rear Wheels – If Equipped ..........504
TIRE PRESSURE MONITOR SYSTEM (TPMS) . .505
▫ Base System ........................ .508
▫ Premium System – If Equipped ............510
▫ Tire Pressure Monitor System (TPMS) Tire Light
Load Inflation Switch Description (2500 Models) –
If Equipped ......................... .514
▫ General Information ...................518
FUEL REQUIREMENTS ..................518
▫ 3.6L And 4.7L Engine ...................518
▫ 5.7L Engine ......................... .519
▫ Reformulated Gasoline .................519
▫ Gasoline/Oxygenate Blends ..............520
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WARNING!
The air suspension system uses a high pressure
volume of air to operate the system. To avoid per-
sonal injury or damage to the system, see your
authorized dealer for service.
Air Suspension Modes
The Air Suspension system has multiple modes to protect
the system in unique situations:
•Tire/Jack Mode
• To assist with changing a spare tire, the air suspen-
sion system has a feature which allows the automatic
leveling to be disabled. This mode is intended to be
used with engine running. Refer to “Electronic Ve-
hicle Information Center (EVIC)” in “Understanding
Your Instrument Panel” for further information. •
Transport Mode
• To assist with flat bed towing, the air suspension
system has a feature which will put the vehicle into
Entry/Exit height and disable the automatic load
leveling system. This mode is intended to be used
with engine running. Refer to “Electronic Vehicle
Information Center (EVIC)” in “Understanding Your
Instrument Panel” for further information.
• Wheel Alignment Mode
• Before performing a wheel alignment this mode
must be enabled. Refer to “Electronic Vehicle Infor-
mation Center (EVIC)” in “Understanding Your In-
strument Panel” for further information.
• Protection Mode
• In order to “protect” the air suspension system, the
vehicle will enter Protection Mode when load level-
ing cannot be achieved. Some driving may be re-
quired to clear the protection mode telltale in the
414 STARTING AND OPERATING
Spare Tire Matching Original Equipped Tire And
Wheel – If Equipped
Your vehicle may be equipped with a spare tire and
wheel equivalent in look and function to the original
equipment tire and wheel found on the front or rear axle
of your vehicle. This spare tire may be used in the tire
rotation for your vehicle. If your vehicle has this option
refer to an authorized tire dealer for the recommended
tire rotation pattern.
Compact Spare Tire – If Equipped
The compact spare is for temporary emergency use only.
You can identify if your vehicle is equipped with a
compact spare by looking at the spare tire description on
the Tire and Loading Information Placard located on the
driver ’s side door opening or on the sidewall of the tire.
Compact spare tire descriptions begin with the letter “T”
or “S” preceding the size designation. Example: T145/
80D18 103M.T, S = Temporary Spare Tire
Since this tire has limited tread life the original equip-
ment tire should be repaired (or replaced) and reinstalled
on your vehicle at the first opportunity.
Do not install a wheel cover or attempt to mount a
conventional tire on the compact spare wheel, since the
wheel is designed specifically for the compact spare tire.
Do not install more than one compact spare tire and
wheel on the vehicle at any given time.WARNING!
Compact spares are for temporary emergency use
only. With these spares, do not drive more than
50 mph (80 km/h). Temporary use spares have limited
tread life. When the tread is worn to the tread wear
indicators, the temporary use spare tire needs to be
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498 STARTING AND OPERATING
WARNING!(Continued)
replaced. Be sure to follow the warnings, which
apply to your spare. Failure to do so could result in
spare tire failure and loss of vehicle control.
Full Size Spare – If Equipped
The full size spare is for temporary emergency use only.
This tire may look like the originally equipped tire on the
front or rear axle of your vehicle, but it is not. This spare
tire may have limited tread life. When the tread is worn
to the tread wear indicators, the temporary use full size
spare tire needs to be replaced. Since it is not the same as
your original equipment tire, replace (or repair) the
original equipment tire and reinstall on the vehicle at the
first opportunity.
Limited-Use Spare – If Equipped
The limited-use spare tire is for temporary emergency
use only. This tire is identified by a label located on the limited-use spare wheel. This label contains the driving
limitations for this spare. This tire may look like the
original equipped tire on the front or rear axle of your
vehicle, but it is not. Installation of this limited-use spare
tire affects vehicle handling. Since it is not the same as
your original equipment tire, replace (or repair) the
original equipment tire and reinstall on the vehicle at the
first opportunity.
WARNING!
Limited-use spares are for emergency use only. In-
stallation of this limited-use spare tire affects vehicle
handling. With this tire, do not drive more than the
speed listed on the limit-use spare wheel. Keep
inflated to the cold tire inflation pressures listed on
your Tire and Loading Information Placard located
on the driver ’s side B-Pillar or the rear edge of the
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STARTING AND OPERATING 499
CAUTION!
3500 Dual Rear Tires may only have one approved
direction of rotation. This is to accommodate the
asymmetrical design (tread pattern) of the On/Off-
Road tire and the use of Outline White Letter (OWL)
tires.
•When replacing a flat, the spare tire may have to be
remounted on the rim, or installed at a different
location, to maintain the correct placement of the
tire on the wheel relative to the tire/wheel position
on the truck. For example, if the spare is used to
replace an outer rear tire it will have to be re-
mounted on the rim so that the wheel is dished
inward. That way the tread design of asymmetrical
tires and the white writing of the OWL tires will
maintain proper position.
TIRE PRESSURE MONITOR SYSTEM (TPMS)
The Tire Pressure Monitor System (TPMS) will warn the
driver of a low tire pressure based on the vehicle recom-
mended cold placard pressure.
The tire pressure will vary with temperature by about 1
psi (6.9 kPa) for every 12°F (6.5°C). This means that when
the outside temperature decreases, the tire pressure will
decrease. Tire pressure should always be set based on
cold inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven for at least
three hours, or driven less than 1 mile (1.6 km) after a
three hour period. The cold tire inflation pressure must
not exceed the maximum inflation pressure molded into
the tire sidewall. Refer to “Tires – General Information”
in “Starting and Operating” for information on how to
properly inflate the vehicle’s tires. The tire pressure will
508 STARTING AND OPERATING
•Seasonal temperature changes will affect tire pressure,
and the TPMS will monitor the actual tire pressure in
the tire.
Base System
The Tire Pressure Monitor System (TPMS) uses wireless
technology with wheel rim mounted electronic sensors to
monitor tire pressure levels. Sensors mounted to each
wheel as part of the valve stem transmit tire pressure
readings to the receiver module.
NOTE: It is particularly important for you to check the
tire pressure in all of the tires on your vehicle monthly
and to maintain the proper pressure.
The TPMS consists of the following components:
• Receiver module,
• Four TPM sensors, and
• TPM Telltale Light The matching full size spare wheel and tire assembly (if
equipped) has a TPM sensor. The matching full size spare
can be used in place of any of the four road tires. The
TPMS will only monitor the pressure in the full size spare
when it is used in place of a road tire. Otherwise, a spare
with a pressure below the low-pressure limit will not
cause the “Tire Pressure Monitoring Telltale Light” to
illuminate or the chime to sound.
Tire Pressure Monitoring Low Pressure Warnings
The “Tire Pressure Monitoring Telltale Light” will
illuminate in the instrument cluster, a “LOW TIRE
PRESSURE” message will display in the EVIC, and a
chime will sound when tire pressure is low in one or
more of the four active road tires. An Inflate to XX
message will also be displayed. Should this occur, you
should stop as soon as possible, check the inflation
pressure of each tire on your vehicle, and inflate each tire
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