SAFETY 289
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 bolts 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 proper closing, latching, and locking.
Fluid Leaks
Check area under the vehicle after overnight parking for
fuel, coolant, oil, or other fluid leaks. Also, if gasoline fumes
are detected or if fuel, or brake fluid leaks are suspected. The
cause should be located and corrected immediately.
• ALWAYS make sure objects cannot fall or slide into the
driver’s side floor area when the vehicle is moving.
Objects can become trapped under accelerator, brake,
or clutch pedals and could cause a loss of vehicle
control.
• NEVER place any objects under the floor mat (e.g., towels, keys, etc.). These objects could change the posi -
tion of the floor mat and may cause interference with
the accelerator, brake, or clutch pedals.
• If the vehicle carpet has been removed and re-installed, always properly attach carpet to the floor and check the
floor mat fasteners are secure to the vehicle carpet.
Fully depress each pedal to check for interference with
the accelerator, brake, or clutch pedals then re-install
the floor mats.
• It is recommended to only use mild soap and water to clean your floor mats. After cleaning, always check
your floor mat has been properly installed and is
secured to your vehicle using the floor mat fasteners by
lightly pulling mat.
WARNING! (Continued)
4
STARTING AND OPERATING 315
The “Transfer Case Position Indicator Light” in the instru-
ment cluster will alert the driver that the vehicle is in
four-wheel drive and that the front and rear driveshafts are
locked together. This light will illuminate when the transfer
case is shifted into either the 4H or 4L position. There is no
light for the 2H or NEUTRAL positions on some models.
When operating your vehicle in 4L, the engine speed is
approximately three times that of the 2H or 4H positions at a
given road speed. Take care not to overspeed the engine and
do not exceed 25 mph (40 km/h).
Proper operation of four-wheel drive vehicles depends on
tires of equal size, type and circumference on each wheel.
Any difference will adversely affect shifting and can cause
damage to the drivetrain.
NOTE:
Do not attempt to make a shift while only the front or rear
wheels are spinning, as this can cause damage to driveline
components.
Because four-wheel drive provides improved traction, there
is a tendency to exceed safe turning and stopping speeds. Do
not go faster than road conditions permit.NOTE:
Delayed shifts out of four-wheel drive may be experienced
due to uneven tire wear, low or uneven tire pressures, exces
-
sive vehicle loading, or cold temperatures.
Two-Wheel Drive High Range (2H)
Rear-Wheel Drive High Range — This range is for normal
street and highway driving on dry hard surfaced roads.
Four-Wheel Drive High Range (4H)
Four-Wheel Drive High Range — This range locks the front
and rear driveshafts together forcing the front and rear
wheels to rotate at the same speed. Additional traction for
loose, slippery road surfaces only.
WARNING!
You or others could be injured or killed if you leave the
vehicle unattended with the transfer case in the
NEUTRAL position without first fully engaging the
parking brake. The transfer case NEUTRAL position
disengages both the front and rear drive shafts from the
powertrain and will allow the vehicle to roll, even if the
transmission is in PARK. The parking brake should
always be applied when the driver is not in the vehicle.
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318 STARTING AND OPERATING
Trailer Decoupling/Unloading - The air suspension system
will load level (lower/exhaust only) once after 12 minutes
after the vehicle is turned off. This allows for easy removal of
a trailer and/or load from the back of the truck by main -
taining the ride height. After 12 minutes you will need to
turn the ignition to the run position for the air suspension to
re-level due to addition/removal of load in the vehicle. If the
air suspension system is disabled using the settings menu
(Tire Jack Mode, Transport Mode, Alignment Mode, or Bed
Lowering Mode) the system will remain disabled when the
vehicle is turned off. Reactivating the air suspension can be
accomplished via the settings menu or driving the vehicle
above 5 mph (8 km/h) for Tire Jack Mode or Alignment
Mode and 16 mph (26 km/h) for Transport Mode and Bed
Lowering Mode.
NOTE:
• Most 3500 models will not lower to Alternate Trailer Height (ATH) when unloaded.
• Refer to “Trailer Towing” in “Starting And Operating” for further information. Ignition OFF Behavior
For a predetermined amount of time after the ignition is off the
air suspension may adjust to maintain a proper appearance.
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 tire, the air suspension system has a
feature which allows the automatic leveling to be disabled. This
mode is intended to be enabled with engine running. Refer to
“Instrument Cluster Display” in “Getting To Know Your Instru
-
ment Panel” or “Uconnect Settings” in “Multimedia” if equipped
with a touch screen radio for further information.
NOTE:
This mode is intended to be enabled with engine running.
WARNING!
The air suspension system uses a high pressure volume
of air to operate the system. To avoid personal injury or
damage to the system, see your authorized dealer for
service.
STARTING AND OPERATING 327
entering any mud hole, get out and determine how deep it
is, if there are any hidden obstacles and if the vehicle can
be safely recovered if stuck.
• Sand – Soft sand is very difficult to travel through with full
tire pressure. When crossing soft sandy spots in a trail
maintain your vehicle's momentum and do not stop. The
key to driving in soft sand using the appropriate tire pres -
sure, accelerating slowly, avoiding abrupt maneuvers and
maintaining the vehicle's momentum. If you are going to
be driving on large soft sandy areas or dunes, reduce your
tire pressure to a minimum of 15 psi (103 kPa) to allow for
a greater tire surface area. Reduced tire pressure will dras -
tically improve your traction and handling, while driving
on the soft sand, but you must return the tires to normal air
pressure before driving on pavement or other hard
surfaces. Be sure you have a way to air the tires back up
prior to reducing the pressure.Crossing Obstacles (Rocks And Other High Points)
While driving off road, you will encounter many types of
terrain. These varying types of terrain bring different types of
obstacles. Before proceeding review the path ahead to deter -
mine the correct approach and your ability to safely recover the
vehicle if something goes wrong. Keeping a firm grip on the
steering wheel, bring the vehicle to a complete stop and then
inch the vehicle forward until it makes contact with the object.
Apply the throttle lightly while holding a light brake pressure
and ease the vehicle up and over the object.
Using A Spotter
There are many times where it is hard to see the obstacle or
determine the correct path. Determining the correct path can
be extremely difficult when you are confronting many obsta -
cles. In these cases have someone guide you over, through, or
around the obstacle. Have the person stand a safe distance in
front of you where they can see the obstacle, watch your tires
and undercarriage, and guide you through.
CAUTION!
Reduced tire pressures may cause tire unseating and
total loss of air pressure. To reduce the risk of tire
unseating, while at a reduced tire pressure, reduce your
speed and avoid sharp turns or abrupt maneuvers.
WARNING!
Crossing obstacles can cause abrupt steering system
loading which could cause you to loose control of your
vehicle.
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332 STARTING AND OPERATING
effectively increasing the water level on the vehicle. Be
sure to consider this when determining the depth and the
ability to safely cross.
• Crossing Puddles, Pools, Flooded Areas Or Other Standing
Water – Puddles, pools, flooded or other standing water areas
normally contain murky or muddy waters. These water types
normally contain hidden obstacles and make it difficult to
determine an accurate water depth, approach angle, and
bottom condition. Murky or muddy water holes are where
you want to hook up tow straps prior to entering. This makes
for a faster, cleaner and easier vehicle recovery. If you are able
to determine you can safely cross, than proceed using the low
and slow method.
• Crossing Ditches, Streams, Shallow Rivers Or Other
Flowing Water – Flowing water can be extremely dangerous.
Never attempt to cross a fast running stream or river even in
shallow water. Fast moving water can easily push your
vehicle downstream sweeping it out of control. Even in very
shallow water, a high current can still wash the dirt out from
around your tires putting you and your vehicle in jeopardy.
There is still a high risk of personal injury and vehicle damage with slower water currents in depths greater than the
vehicle's running ground clearance. You should never
attempt to cross flowing water which is deeper than the
vehicle's running ground clearance. Even the slowest current
can push the heaviest vehicle downstream out of control if the
water is deep enough to push on the large surface area of the
vehicle's body. Before you proceed determine the speed of the
current, the water's depth, approach angle, bottom condition
and if there are any obstacles, then cross at an angle heading
slightly upstream using the low and slow technique.
Airing Down For Off-Road Driving
Running lower tire pressure off-road can improve your ride
comfort and vehicle traction. Reducing the tire air pressure
allows the tire to bulge slightly, improving its surface area
for better flotation and ability to mold or form to the ground
contour. Different terrain, tires, and vehicles require
different tire pressure. Hard surfaces like rock and heavier
vehicles require higher pressures than softer surfaces such as
CAUTION!
Muddy waters can reduce the cooling system
effectiveness by depositing debris onto the radiator.
WARNING!
Never drive through fast moving deep water. It can push
your vehicle downstream, sweeping it out of control.
This could put you and your passengers at risk of injury
or drowning.
STARTING AND OPERATING 333
sand and lighter vehicles. You will need to experiment to
determine what is right for your situation. It is easier and
faster to let air out than it is to replace it so, start high and
lower it as required. Remember you must return the tires to
normal air pressure before driving on road or at highway
conditions. Be sure you have a way to return the tires to their
normal on road air pressure.
Vehicle Recovery
If you drive off-road, you may encounter a situation where
you will need to recover your vehicle. Vehicle recovery
should always be given consideration before attempting a
questionable obstacle. You should never go off-road driving
without the ability to recover your vehicle from a situation.
Having another vehicle with you usually works best for most
situations. The first thing to do is assess the situation. Why
are you stuck? Are you hung up on something? Would it be
easier to go forward or to go backward? Can you still movethe vehicle? Is there an anchor point to winch to? Are you
alone or do you have another vehicle to help? Is there high
risk of vehicle damage during the recovery process?
Answering these questions will help you determine the best
method of recovery. If you can still move the vehicle slightly
and the only issue is slick ground, then rock cycling your
vehicle would be the first choice. If you have ample room, an
additional vehicle and there is low risk of vehicle impinge
-
ment on the surroundings, then using a tow strap to the
vehicle tow hooks would be fast and easy. If the vehicle is
severely hung up or in a situation where great care needs to
be taken during the recovery, then nothing can do the job
better than a winch. If you are severely hung up on some -
thing you should jack the vehicle up and stack something
under the wheels to allow the vehicle to roll off the object
without causing further damage. This should be tried before
attempting any recovery method.
CAUTION!
Reduced tire pressure increases the risk of tire damage
and may cause tire unseating with total loss of air
pressure. To reduce the risk of tire unseating, while at a
reduced tire pressure, drive at slower speeds and avoid
sharp turns or abrupt maneuvers.
CAUTION!
Pulling the vehicle off an obstacle, without first clearing
the object, may result in additional underbody damage.
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410 STARTING AND OPERATING
Loose Fuel Filler Cap Message
If the vehicle diagnostic system determines that the
fuel filler cap is loose, improperly installed, or
damaged, a loose gascap indicator will display in the
instrument cluster telltale display area. Refer to “Instrument
Cluster Display” in “Getting To Know Your Instrument
Panel” for further information. Tighten the fuel filler cap
properly and push the RIGHT button to turn off the message.
If the problem continues, the message will appear the next
time the vehicle is started.
VEHICLE LOADING
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total permissible weight of your vehicle
including driver, passengers, vehicle, options and cargo. The
label also specifies maximum capacities of front and rear axle
systems (GAWR). Total load must be limited so GVWR and
front and rear GAWR are not exceeded.
Payload
The payload of a vehicle is defined as the allowable load
weight a truck can carry, including the weight of the driver,
all passengers, options and cargo.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum permissible load on the front
and rear axles. The load must be distributed in the cargo area
so that the GAWR of each axle is not exceeded.
Each axle GAWR is determined by the components in the
system with the lowest load carrying capacity (axle, springs,
tires or wheels). Heavier axles or suspension components
sometimes specified by purchasers for increased durability
does not necessarily increase the vehicle's GVWR.
Tire Size
The tire size on the Vehicle Certification Label represents the
actual tire size on your vehicle. Replacement tires must be
equal to the load capacity of this tire size.
Rim Size
This is the rim size that is appropriate for the tire size listed.
Inflation Pressure
This is the cold tire inflation pressure for your vehicle for all
loading conditions up to full GAWR.
420 STARTING AND OPERATING
Towing Requirements — Tires
• Do not attempt to tow a trailer while using a compact sparetire.
• Do not drive more than 50 mph (80 km/h) when towing while using a full size spare tire.
• Proper tire inflation pressures are essential to the safe and satisfactory operation of your vehicle. Refer to “Tires” in
“Servicing And Maintenance” for proper tire inflation
procedures.
• Check the trailer tires for proper tire inflation pressures before trailer usage.
• Check for signs of tire wear or visible tire damage before towing a trailer. Refer to “Tires” in “Servicing And Main -
tenance” for the proper inspection procedure.
• When replacing tires, refer to “Tires” in “Servicing And Maintenance” for the proper tire replacement procedures.
Replacing tires with a higher load carrying capacity will
not increase the vehicle's GVWR and GAWR limits. Towing Requirements — Trailer Brakes
• Do
not interconnect the hydraulic brake system or vacuum
system of your vehicle with that of the trailer. This could
cause inadequate braking and possible personal injury.
• An electronically actuated trailer brake controller is required when towing a trailer with electronically actu -
ated brakes. When towing a trailer equipped with a
hydraulic surge actuated brake system, an electronic brake
controller is not required.
• Trailer brakes are recommended for trailers over 1,000 lbs (453 kg) and required for trailers in excess of 2,000 lbs (907 kg).
WARNING!
• Do not connect trailer brakes to your vehicle's hydraulic brake lines. It can overload your brake
system and cause it to fail. You might not have brakes
when you need them and could have an accident.
• Towing any trailer will increase your stopping distance. When towing, you should allow for addi -
tional space between your vehicle and the vehicle in
front of you. Failure to do so could result in an accident.