Page 118 of 675
• Use the appropriate transmission gear to prevent
engine lugging.
• Observe vehicle oil pressure and temperature indica-
tors.
• Check the coolant and oil levels frequently.
• Vary throttle position at highway speeds when carry-
ing or towing significant weight.
NOTE: Light duty operation such as light trailer towing
or no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy and
power may be seen at this time.
For additional vehicle break-in requirements, refer to
“Trailer Towing” in “Starting and Operating” of the
Owner ’s Manual. Because of the construction of the Cummins turbo-
charged diesel engine, engine run-in is enhanced by
loaded operating conditions which allow the engine
parts to achieve final finish and fit during the first 6,000
miles (10 000 km).
SAFETY TIPS
Transporting Passengers
NEVER TRANSPORT PASSENGERS IN THE CARGO
AREA.116 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE
Page 239 of 675

1. Tachometer
• Indicates the engine speed in revolutions per minute
(RPM x 1000).
2. Voltmeter
• When the engine is running, the gauge indicates the
electrical system voltage. The pointer should stay
within the normal range if the battery is charged. If
the pointer moves to either extreme left or right and
remains there during normal driving, the electrical
system should be serviced.
NOTE: The voltmeter may show a gauge fluctuation at
various engine temperatures. This cycling operation is
caused by the post-heat cycle of the intake manifold
heater system. The number of cycles and the length of the
cycling operation is controlled by the engine control
module. Post-heat operation can run for several minutes,
and then the electrical system and voltmeter needle will
stabilize. 3. Oil Pressure Gauge
• The pointer should always indicate some oil pres-
sure when the engine is running. A continuous high
or low reading under normal driving conditions may
indicate a lubrication system malfunction. Immedi-
ate service should be obtained from an authorized
dealer.
4. Speedometer
• Indicates vehicle speed.
5. Fuel Gauge
• The pointer shows the level of fuel in the fuel tank
when the ignition switch is in the ON/RUN position.
• The fuel pump arrow symbol points to the
side of the vehicle where the fuel door is located. 4UNDERSTANDING YOUR INSTRUMENT PANEL 237
Page 248 of 675
Oil Pressure Warning Light
Red Telltale
Light What It Means
Oil Pressure Warning Light
This light indicates low engine oil pressure. If the light turns on while driving, stop the ve-
hicle and shut off the engine as soon as possible. A chime will sound when this light turns
on.
Do not operate the vehicle until the cause is corrected. This light does not indicate how
much oil is in the engine. The engine oil level must be checked under the hood.246 UNDERSTANDING YOUR INSTRUMENT PANEL
Page 279 of 675

Vehicle Info Menu Item
Push and release the UP or DOWN arrow button
until the Vehicle Info menu item is highlighted in the
EVIC. Push and release the RIGHT arrow button
to enter the submenus items of Vehicle Info. follow the
directional prompts to access or reset any of the
following Vehicle Info submenu items:
• Tire Pressure
• Coolant Temp
• Transmission Temp (Automatic only)
• Oil Temp
• Oil Pressure
• Oil Life
• Battery Voltage
• Gauge Summary • Engine Hours
Fuel Economy Menu Item
Push and release the UP or DOWN arrow button
until the Fuel Economy menu item is highlighted.
Push and Hold the RIGHT arrow button to reset
Average Fuel Economy.
• Current Fuel Economy Gauge
• Average Fuel Economy value
• Range to Empty
• Dual Fuel Tank levels — If Equipped
• Push and release the RIGHT arrow button to
display the Fuel Tank Level submenu item. Your
EVIC will display the fuel levels of the Front and
Rear fuel tanks. The fuel is automatically trans-
ferred from the Rear tank to the Front tank based on 4UNDERSTANDING YOUR INSTRUMENT PANEL 277
Page 571 of 675

CAUTION! (Continued)result in more costly repairs, damage to other
components or negatively impact vehicle perfor-
mance. Immediately have potential malfunctions
examined by an authorized dealer or qualified
repair center.
• Your vehicle has been built with improved fluids
that protect the performance and durability of your
vehicle and also allow extended maintenance inter-
vals. Do not use chemical flushes in these compo-
nents as the chemicals can damage your engine,
transmission, or air conditioning. Such damage is
not covered by the New Vehicle Limited Warranty.
If a flush is needed because of component malfunc-
tion, use only the specified fluid for the flushing
procedure. Engine Oil
Checking Oil Level
To assure proper lubrication of your vehicle’s engine, the
engine oil must be maintained at the correct level. Check
the oil level at regular intervals, such as every fuel stop.
The best time to check the engine oil level is about five
minutes after a fully warmed up engine is shut off.
Checking the oil while the vehicle is on level ground will
improve the accuracy of the oil level readings. Always
maintain the oil level within the SAFE zone on the
dipstick. Adding one quart of oil when the reading is at
the bottom of the SAFE zone will result in a reading at the
top of the safe zone on these engines. 7MAINTAINING YOUR VEHICLE 569
Page 596 of 675

With disc brakes the fluid level can be expected to fall as
the brake linings wear. However, an unexpected drop in
fluid level may be caused by a leak and a system check
should be conducted.
Use only the manufacturer’s recommended brake fluid.
Refer to “Fluids, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information.
WARNING!• Use only manufacturer’s recommended brake
fluid. Refer to “Fluids, Lubricants, And Genuine
Parts” in “Maintaining Your Vehicle” for further
information. 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. (Continued) WARNING! (Continued)• To avoid contamination from foreign matter or
moisture, use only new brake fluid or fluid that has
been in a tightly closed container. Keep the master
cylinder reservoir cap secured at all times. Brake
fluid in a open container absorbs moisture from the
air resulting in a lower boiling point. This may
cause it to boil unexpectedly during hard or pro-
longed braking, resulting in sudden brake failure.
This could result in a collision.
• Overfilling the brake fluid reservoir can result in
spilling brake fluid on hot engine parts, causing
the brake fluid to catch fire. Brake fluid can also
damage painted and vinyl surfaces, care should be
taken to avoid its contact with these surfaces.
• Do not allow petroleum based fluid to contaminate
the brake fluid. Brake seal components could be
damaged, causing partial or complete brake failure.
This could result in a collision.594 MAINTAINING YOUR VEHICLE
Page 598 of 675

Lubricant Selection
Refer to “Fluids, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information.
NOTE: The presence of water in the gear lubricant will
result in corrosion and possible failure of differential
components. Operation of the vehicle in water, as may be
encountered in some off-highway types of service, will
require draining and refilling the axle to avoid damage.
Limited-Slip Differentials DO NOT REQUIRE any
limited slip oil additive (friction modifiers).
NOTE: Slight noise and mild shuddering may be evident
while turning a vehicle with limited slip differential on
concrete or dry pavement. These conditions should be
considered normal operation of the limited slip differen-
tial. Transfer Case
Drain And Refill
Refer to the “Maintenance Schedule” for the proper
maintenance intervals.
Lubricant Selection
Refer to “Fluids, Lubricants, And Genuine Parts” in
“Maintaining Your Vehicle” for further information.
Fluid Level Check
This fluid level can be checked by removing the filler
plug. The fluid level should be to the bottom edge of the
filler plug hole with the vehicle in a level position.
Automatic Transmission — If Equipped
Selection Of Lubricant
It is important to use the proper transmission fluid to
ensure optimum transmission performance and life. Use596 MAINTAINING YOUR VEHICLE
Page 601 of 675

4. Fully apply the parking brake and press the brake
pedal.
5. Place the gear selector momentarily into each gear
position (allowing time for the transmission to fully
engage in each position), ending with the transmission
in PARK.
6. Wipe the area around the dipstick clean to prevent dirt
from entering the transmission.
7. Remove the dipstick, wipe it clean and reinsert it until
seated.
8. Remove the dipstick again and note the fluid level on
both sides. The fluid level reading is only valid if there
is a solid coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full of fluid
if the actual level is at or above the hole. The fluid level
should be between the “HOT” (upper) reference holes
on the dipstick at normal operating temperature. If the fluid level is low, add fluid through the dipstick tube
to bring it to the proper level. Do not overfill. Use
ONLY the specified fluid (see Fluids, Lubricants, and
Genuine Parts for fluid specifications). After adding
any quantity of oil through the dipstick tube, wait a
minimum of two minutes for the oil to fully drain into
the transmission before rechecking the fluid level.
NOTE: If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the dipstick
with the fluid at 60-70°F / 16-21°C for 66RFE transmis-
sion, or 68-86°F / 20-30°C for AS66RC transmission. Only
use the COLD region of the dipstick as a rough reference
when setting the fluid level after a transmission service
or fluid change. Re-check the fluid level, and adjust as
required, once the transmission reaches normal operating
temperature. 7MAINTAINING YOUR VEHICLE 599