Page 371 of 527

The automatic transmission fluid and filter should be
changed if you REGULARLY tow a trailer for more than
45 minutes of continuous operation. See Maintenance
Schedule in section 8 of this manual for transmission
fluid change intervals.
NOTE:Check the automatic transmission fluid level
before towing.
Towing Tips Ð Tow/Haul (If Equipped)
To reduce potential for automatic transmission overheat-
ing, turn the ªTOW HAULº feature ON when driving in
hilly areas or downshift the transmission (using the
Auto-6 [ERS] switch).
Towing Tips Ð Electronic Speed Control (If
Equipped)
þ
Don't use in hilly terrain or with heavy loads.
þWhen using the speed control, if you experience speed
drops greater than 10 mph (16 km/h), disengage until
you can get back to cruising speed.
þUse speed control in flat terrain and with light loads to
maximize fuel efficiency.
Towing Tips Ð Cooling System
To reduce potential for engine and transmission over-
heating, take the following actions:
þCity Driving
When stopped for short periods of time, put transmission
in neutral and increase engine idle speed.
þHighway Driving
Reduce speed.
þAir Conditioning
Turn off temporarily.
STARTING AND OPERATING 369
5
Page 372 of 527
þrefer to Cooling System Operating information in the
Maintenance section of this manual for more informa-
tion.
Trailer Towing Mirrors Ð If Equipped
These mirrors are designed with an adjustable mirror
head to provide a greater vision range when towing
extra-wide loads. To change position inboard or out-
board, the mirror head should be rotated (flipped Out or
In). A small blindspot mirror is integrated onto the main
mirror surface.
NOTE: Fold the7x10inch trailer towing mirrors
rearward prior to entering an automated car wash.
Blindspot Mirror
370 STARTING AND OPERATING
Page 376 of 527

NOTE:During snowplow usage on vehicles equipped
with an overhead console module, the outside tempera-
ture display will show higher temperatures than the
outside ambient temperature. The higher displayed tem-
perature is due to blocked or reduced airflow to the
underhood ambient temperature sensor by the snow-
plow. This is common and outside temperature display
operation will return to normal when the snowplow is
removed.
General Maintenance
Snowplows should be maintained in accordance with the
plow manufacturer's instructions.
Keep all snowplow electrical connections and battery
terminals clean and free of corrosion.When plowing snow, to avoid transmission and driv-
etrain damage, the following precautions should be ob-
served.
²Operate with transfer case in 4L when plowing small
or congested areas where speeds are not likely to
exceed 15 mph (24 km/h). At higher speeds operate in
4H.
²Vehicles with 68RFE transmissions should use 4L
range when plowing deep or heavy snow for extended
periods of time to avoid transmission overheating.
²Do not shift the transmission unless the engine has
returned to idle and wheels have stopped. Make a
practice of stepping on the brake pedal before shifting
the transmission.
374 STARTING AND OPERATING
Page 407 of 527
MAINTAINING YOUR VEHICLE
CONTENTS
mEngine Compartment Ð 6.7L Diesel Engine....408
mOnboard Diagnostic System (OBD II).........409
mReplacement Parts......................409
mEngine Data Plate......................410
mAuthorized Dealer Service................410
mService Information.....................410
mMaintenance Procedures..................412
NEngine Oil..........................413
NDrive Belt...........................418NEngine Air Cleaner Filter (6.7L Diesel
Engines)............................419
NDraining Fuel/Water Separator Filter (6.7L
Diesel Engine).......................422
NIntervention Regeneration Strategy ± EVIC
Message Process Flow (Catalyst Full Message)
(6.7L Diesel Engines Only)...............425
NMaintenance Free Batteries...............428
NAir Conditioner Maintenance.............430
NPower Steering Ð Fluid Check............431
7
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NFront Suspension Ball Joints..............431
NSteering Linkage Ð Inspection............432
NFront Prop Shaft Lubrication.............432
NFront Axle Universal Drive Joints And Ball
Joints..............................432
NBody Lubrication.....................433
NWindshield Wiper Blades................433
NWindshield Washers...................434
NExhaust System......................435
NCooling System.......................436
NFan ...............................442
NCharge Air Cooler (Inter-Cooler)..........442
NHoses And Vacuum/Vapor Harnesses.......443NBrake System........................443
NClutch Linkage.......................445
NClutch Hydraulic System................445
NRear Axle And 4X4 Front Driving Axle Fluid
Level..............................446
NTransfer Case Ð If Equipped.............446
NManual Transmission Ð If Equipped.......447
NAutomatic Transmission................447
NFront Wheel Bearings..................450
NNoise Control System Required Maintenance
& Warranty.........................451
NAppearance Care And Protection From
Corrosion...........................455
mFuses (Integrated Power Module)...........459
406 MAINTAINING YOUR VEHICLE
Page 411 of 527

ONBOARD DIAGNOSTIC SYSTEM (OBD II)
Vehicles equipped with California emissions controls
have a sophisticated onboard diagnostic system called
OBDII. This system monitors the performance of the
emissions, engine, and automatic transmission control
systems. When these systems are operating properly,
your vehicle will provide excellent performance and fuel
economy, as well as engine emissions well within current
government regulations.
If any of these systems require service, the OBD II system
will turn on the ªMalfunction Indicator Light.º It will
also store diagnostic codes and other information to
assist your service technician in making repairs. Al-
though your vehicle will usually be driveable and not
need towing, see your dealer for service as soon as
possible.CAUTION!
Prolonged driving with the ªMalfunction Indicator
Lightº on could cause further damage to the emission
control system. It could also affect fuel economy and
driveability. The vehicle must be serviced before any
emissions tests can be performed.
If the ªMalfunction Indicator Lightº is flashing,
severe catalytic converter damage and power loss
will soon occur. Immediate service is required.
REPLACEMENT PARTS
Use of genuine Mopartparts for normal/scheduled
maintenance and repairs is highly recommended to en-
sure the designed performance. Damage or failures
caused by the use of non-Mopartparts for maintenance
and repairs will not be covered by the manufacturer's
warranty.
MAINTAINING YOUR VEHICLE 409
7
Page 413 of 527
CAUTION!
To maintain your vehicle safely follow these guide-
lines:
²Watch your vehicle's mileage and check your
Maintenance Schedules regularly for required ser-
vicing. Excessive wear or damage to certain vehicle
components can result if required services are not
performed.
²If you have your vehicle undercoated, inspect for
undercoating material on the propeller shafts.
Such material could cause the shafts to become
unbalanced and result in drivetrain vibrations.
Remove any undercoating with solvent.
²If you have your vehicle undercoated, make sure
no undercoating material is sprayed on the ex-
haust system or components of the seat belt
system.NOTE:It is not possible for the manufacturer and
Cummins, Inct. to anticipate every possible circumstance
that can involve a potential hazard.
MAINTAINING YOUR VEHICLE 411
7
Page 414 of 527

WARNING!
To maintain your vehicle safely and avoid personal injury, follow these
guidelines:
²Never spray or pour diesel fuel, flammable liquid or starting fluids
(ether) into the air cleaner assembly, air intake piping or turbocharger
inlet in an attempt to start the vehicle, unintended engine acceleration
may occur.
²Do not use alcohol or gasoline as a fuel blending agent. They can be
unstable under certain conditions and be hazardous or explosive
when mixed with diesel fuel.
²If an engine has been operating and the coolant is hot, allow the
engine to cool before you slowly loosen the filler cap and relieve the
pressure from the cooling system.
²To avoid burns, remember that the engine components will stay hot
after the engine is shut off.
²Do not use gasoline or other flammable materials to clean parts.
Always use approved cleaning solvents.
²Relieve all pressure in the fuel, oil and cooling systems before any
lines, fittings or related items are removed or disconnected. Be alert
for possible pressure when disconnecting any device from a system
that utilizes pressure. Do not check for pressure leaks with your hand.
High pressure oil or fuel can cause personal injury.
²Important: All maintenance other than that listed in this manual, as
well as some procedures listed here, MUST be performed by your
authorized dealer. Your authorized dealer has been trained and has
the necessary parts to maintain your engine.
WARNING!
Do not open the high pressure fuel system with the
engine running. Engine operation causes high fuel
pressure. High pressure fuel spray can cause serious
injury or death.
MAINTENANCE PROCEDURES
The pages that follow contain therequiredmaintenance
services determined by the engineers who designed your
vehicle.
Besides the maintenance items for which there are fixed
maintenance intervals, there are other items that should
operate satisfactorily without periodic maintenance.
However, if a malfunction of these items does occur, it
could adversely affect the engine or vehicle performance.
These items should be inspected if a malfunction is
observed or suspected.
412 MAINTAINING YOUR VEHICLE