178STARTING AND OPERATING
VEHICLE LOADING
GROSS VEHICLE WEIGHT RATING
(GVWR)
The GVWR is the total allowable weight of your vehicle.
This includes driver, passengers, cargo and tongue
weight. The total load must be limited so that you do not
exceed the GVWR.
PAYLOAD
The payload of a vehicle is defined as the allowable weight
a vehicle 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, do not necessarily increase the
vehicle's GVWR or GAWR.
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.
CURB WEIGHT
The curb weight of a vehicle is defined as the total weight
of the vehicle with all fluids, including vehicle fuel, at full
capacity conditions, and with no occupants or cargo
loaded into the vehicle. The front and rear curb weight
values are determined by weighing your vehicle on a
commercial scale before any occupants or cargo are
added.
LOADING
The actual total weight and the weight of the front and rear
of your vehicle at the ground can best be determined by
weighing it when it is loaded and ready for operation.
The entire vehicle should first be weighed on a commercial
scale to ensure that the GVWR has not been exceeded.
The weight on the front and rear of the vehicle should then
be determined separately to be sure that the load is
properly distributed over the front and rear axles.
Weighing the vehicle may show that the GAWR of either
the front or rear axles has been exceeded but the total
load is within the specified GVWR. If so, weight must be shifted from front to rear or rear to
front as appropriate until the specified weight limitations
are met. Store the heavier items down low and be sure
that the weight is distributed equally. Stow all loose items
securely before driving.
NOTE:
Improper weight distributions can have an adverse
effect on the way your vehicle steers and handles and
the way the brakes operate.
Air suspension vehicle may limit off-road heights if
loaded beyond recommended values for vehicle GVWR
and GAWR.
TRAILER TOWING
In this section you will find safety tips and information on
limits to the type of towing you can reasonably do with your
vehicle. Before towing a trailer, carefully review this
information to tow your load as efficiently and safely as
possible.
To maintain the New Vehicle Limited Warranty coverage,
follow the requirements and recommendations in this
manual concerning vehicles used for trailer towing.
WARNING!
Do not load your vehicle any heavier than the GVWR or
the maximum front and rear GAWR. If you do, parts on
your vehicle can break, or it can change the way your
vehicle handles. This could cause you to lose control.
Overloading can shorten the life of your vehicle.
23_WS_OM_EN_USC_t.book Page 178
SAFETY289
PERIODIC SAFETY CHECKS YOU SHOULD
M
AKE 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 lug nut/bolt torque 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.
EXHAUST GAS
The best protection against carbon monoxide entry into
the vehicle body is a properly maintained engine exhaust
system. Whenever a change is noticed in the sound of the exhaust
system, when exhaust fumes can be detected inside the
vehicle, or when the underside or rear of the vehicle is
damaged, have an authorized dealer inspect the complete
exhaust system and adjacent body areas for broken,
damaged, deteriorated, or mispositioned parts. Open
seams or loose connections could permit exhaust fumes
to seep into the passenger compartment. In addition,
inspect the exhaust system each time the vehicle is raised
for lubrication or oil change. Replace as required.
CARBON MONOXIDE WARNINGS
WARNING!
Exhaust gases can injure or kill. They contain carbon
monoxide (CO), which is colorless and odorless.
Breathing it can make you unconscious and can
eventually poison you. To avoid breathing (CO), follow
these safety tips:
Do not run the engine in a closed garage or in
confined areas any longer than needed to move your
vehicle in or out of the area.
If you are required to drive with the trunk/liftgate/
rear doors open, make sure that all windows are
closed and the climate control BLOWER switch is set
at high speed. DO NOT use the recirculation mode.
If it is necessary to sit in a parked vehicle with the
engine running, adjust your heating or cooling
controls to force outside air into the vehicle. Set the
blower at high speed.
WARNING!
Carbon monoxide (CO) in exhaust gases is deadly.
Follow the precautions below to prevent carbon
monoxide poisoning:
Do not inhale exhaust gases. They contain carbon
monoxide, a colorless and odorless gas, which can
kill. Never run the engine in a closed area, such as a
garage, and never sit in a parked vehicle with the
engine running for an extended period. If the vehicle
is stopped in an open area with the engine running
for more than a short period, adjust the ventilation
system to force fresh, outside air into the vehicle.
Guard against carbon monoxide with proper mainte -
nance. Have the exhaust system inspected every
time the vehicle is raised. Have any abnormal condi -
tions repaired promptly. Until repaired, drive with all
side windows fully open.
6
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309
SERVICING AND MAINTENANCE
SCHEDULED SERVICING
Your vehicle is equipped with an automatic oil change
indicator system. The oil change indicator system will
remind you that it is time to take your vehicle in for
scheduled maintenance.
Based on engine operation conditions, the oil change
indicator message will illuminate. This means that service
is required for your vehicle. Operating conditions such as
frequent short-trips, trailer tow, extremely hot or cold
ambient temperatures, and extended idling will influence
when the “Oil Change Required” message is displayed.
Have your vehicle serviced as soon as possible, within the
next 500 miles (805 km).An authorized dealer will reset the oil change indicator
message after completing the scheduled oil change or for
engine oil life reset procedure Úpage 101.
NOTE:3.0L & 5.7L Engines:
Under no circumstances should oil
change intervals exceed 10,000 miles (16,000 km), or
12 months, whichever comes first. The engine controller
also monitors the number of hours of engine run time, and
will illuminate the oil change indicator after 350 hours
(which is not likely to be exceeded except for certain fleet
customers with extended engine idling periods).
6.4L Engines: Under no circumstances should oil change
intervals exceed 6,000 miles (10,000 km), or 6 months,
whichever comes first. The engine controller also monitors
the number of hours of engine run time, and will illuminate
the oil change indicator after 350 hours (which is not likely
to be exceeded except for certain fleet customers with
extended engine idling periods). Once A Month Or Before A Long Trip:
Check engine oil level
Check windshield washer fluid level
Check the tire inflation pressures and look for unusual
wear or damage
Check the fluid levels of the coolant reservoir, brake
master cylinder and fill as needed.
Check function of all interior and exterior lights
8
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SERVICING AND MAINTENANCE311
Inspect the front and rear axle fluid, change if
using your vehicle for police, taxi, fleet, off-road
or frequent trailer towing. X
X X XX XX
Inspect the brake linings, parking brake
function. X
X X XX XX
Inspect transfer case fluid. XX XXX
Additional Maintenance
Replace engine air cleaner filter. XX XXX
Replace the cabin air filter. To be replaced every 12,000 miles (19,000 km).
Replace spark plugs (3.0L Engine).
1X X Replace spark plugs (5.7L Engine).
1
X Replace spark plugs (6.4L Engine).
1
X
Flush and replace the engine coolant at
10 years or 150,000 miles (240,000 km)
whichever comes first. X
X
Mileage Or Time Passed (Whichever
Comes First)
20,000
30,000
40,000
50,000
60,000
70,000
80,000
90,000
100,000
110,000
120,000
130,000
140,000
150,000
Or Years: 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Or Kilometers:
32,000
48,000
64,000
80,000
96,000
112,000
128,000
144,000
160,000
176,000
192,000
208,000
224,000
240,000
8
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SERVICING AND MAINTENANCE313
ENGINE COMPARTMENT
3.0L ENGINE
1 — Intercooler Coolant Pressure Cap 5 — Battery
2 — Engine Coolant Pressure Cap 6 — Engine Air Cleaner Filter
3 — Engine Oil Fill Cap 7 — Washer Fluid Reservoir Cap
4 — Brake Fluid Reservoir Cap 8 — Power Distribution Center (Fuses)
8
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314SERVICING AND MAINTENANCE
5.7L ENGINE
1 — Engine Air Cleaner Filter 6 — Engine Coolant Reservoir Cap
2 — Engine Oil Fill Cap 7 — Engine Coolant Pressure Cap
3 — Engine Oil Dipstick 8 — Power Distribution Center (Fuses)
4 — Brake Fluid Reservoir Cap 9 — Washer Fluid Reservoir Cap
5 — Battery
23_WS_OM_EN_USC_t.book Page 314
SERVICING AND MAINTENANCE315
6.4L ENGINE
1 — Engine Coolant Pressure Cap 5 — Battery
2 — Engine Oil Fill Cap 6 — Engine Air Cleaner Filter
3 — Engine Oil Dipstick 7 — Washer Fluid Reservoir Cap
4 — Brake Fluid Reservoir Cap 8 — Power Distribution Center (Fuses)
8
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328SERVICING AND MAINTENANCE
(Continued)
Coolant Level
The coolant bottle provides a quick visual method for
determining that the coolant level is adequate. With the
engine off and cold, the level of the engine coolant
(antifreeze) in the bottle should be between the ranges
indicated on the bottle.
The radiator normally remains completely full, so there is
no need to remove the radiator/coolant pressure cap
unless checking for engine coolant freeze point or
replacing coolant. Advise your service attendant of this. As
long as the engine operating temperature is satisfactory,
the coolant bottle need only be checked once a month.
When additional engine coolant is needed to maintain the
proper level, only OAT coolant that meets the
requirements of the manufacturer Material Standard
MS.90032 should be added to the coolant bottle. Do not
overfill.
Cooling System Notes
NOTE:When the vehicle is stopped after a few miles/kilometers
of operation, you may observe vapor coming from the front
of the engine compartment. This is normally a result of
moisture from rain, snow, or high humidity accumulating
on the radiator and being vaporized when the thermostat
opens, allowing hot engine coolant (antifreeze) to enter
the radiator. If an examination of your engine compartment shows no
evidence of radiator or hose leaks, the vehicle may be
safely driven. The vapor will soon dissipate.
Do not overfill the coolant expansion bottle.
Check the coolant freeze point in the radiator and in
the coolant expansion bottle. If engine coolant needs
to be added, the contents of the coolant expansion
bottle must also be protected against freezing.
If frequent engine coolant additions are required, the
cooling system should be pressure tested for leaks.
Maintain engine coolant concentration at a minimum
of 50% OAT coolant (conforming to MS.90032) and
distilled water for proper corrosion protection of your
engine which contains aluminum components.
Make sure that the coolant expansion bottle overflow
hoses are not kinked or obstructed.
Keep the front of the radiator clean. If your vehicle is
equipped with air conditioning, keep the front of the
condenser clean.
Do not change the thermostat for Summer or Winter
operation. If replacement is ever necessary, install
ONLY the correct type thermostat. Other designs may
result in unsatisfactory engine cooling performance,
poor gas mileage, and increased emissions.
BRAKE SYSTEM
In order to ensure brake system performance, all brake
system components should be inspected periodically. For
the proper maintenance intervals
Úpage 310.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should be checked
whenever the vehicle is serviced, or immediately if the
Brake System Warning Light is on. If necessary, add fluid
to bring level within the designated marks on the side of
the reservoir of the brake master cylinder. Be sure to clean
the top of the master cylinder area before removing cap.
With disc brakes, fluid level can be expected to fall as the
brake pads wear. Brake fluid level should be checked
when pads are replaced. If the brake fluid is abnormally
low, check the system for leaks.
WARNING!
Riding the brakes can lead to brake failure and possibly
a collision. Driving with your foot resting or riding on the
brake pedal can result in abnormally high brake
temperatures, excessive lining wear, and possible brake
damage. You would not have your full braking capacity
in an emergency.
WARNING!
Use only manufacturer's recommended brake fluid Úpage 377. Using the wrong type of brake fluid can
severely damage your brake system and/or impair its
performance. The proper type of brake fluid for your
vehicle is also identified on the original factory
installed hydraulic master cylinder reservoir.
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