
delayed. Shifts into 5th and 6th gear are still allowed
under steady cruise conditions. Closed throttle down-
shifts (for improved engine braking) may occur during
steady braking maneuvers. Pressing the switch a second
time restores normal operation. Normal operation is
always the default at engine start-up.
The TOW HAUL light will illuminate in the instrument
cluster to indicate when the switch has been activated. If
the TOW HAUL modes are desired, the button must be
pressed each time the engine is started.
Electronic Range Select (ERS) Operation
The Auto±6 Electronic Range Select (ERS) shift control
allows you to move the switch down (-) or up (+) when
the shifter is in the D (Drive) position, allowing the
selection of the desired top gear. For example, if the
driver shifts the transmission into 3rd gear, the transmis-
sion will never shift above 3rd gear, but can shift down to
2nd or 1st gear, when needed.Switching from ERS to D-Mode can be done at any
vehicle speed. To switch from ªDriveº mode to ªERSº
mode, press the switch down (-) once. The current gear
will be maintained as the top gear. To disable ERS, simply
press and hold the switch up (+) until ªDº is displayed in
the instrument cluster odometer.
WARNING!
Do not downshift for additional engine braking on a
slippery surface. The drive wheels could lose their
grip and the vehicle could skid.
Screen Display12 3456D
Actual Gear(s)
Allowed1 1-2 1-3 1-4 1-5 1-6 1-6
STARTING AND OPERATING 289
5

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

Engine Air Cleaner Filter (6.7L Diesel Engines)
CAUTION!
All air entering the engine intake must be filtered.
The abrasive particles in unfiltered air will cause
rapid wear to engine components.
The condition of the air cleaner filter is monitored by the
Engine Control Module. The Electronic Vehicle Informa-
tion Center (EVIC) will display SERVICE AIR FILTER
when service is required.
Do not remove the top of the air filter housing to
inspect the filter element on your diesel engine under
normal operating conditions.
The EVIC message SERVICE AIR FILTER could be dis-
played periodically. This is because engine air flow
requirements change based on driving conditions. As thefilter becomes more restrictive and air flow requirements
increase the EVIC message SERVICE AIR FILTER will be
displayed. The message may not be displayed in subse-
quent drive cycles if the same conditions are not met. The
air filter element should be replaced within 250 miles
from the first time this message is displayed to ensure
proper engine operation during all driving conditions.
The air filter housing on your vehicle may also come
equipped with a Filter MinderŸ. This is an air flow
restriction gauge that will indicate when the filter ele-
ment needs to be replaced.
CAUTION!
Driving with a restricted air filter can cause engine
damage.
MAINTAINING YOUR VEHICLE 419
7

To achieve these emission standards, your vehicle is
equipped with a state of the art engine and exhaust
system. The engine and exhaust aftertreatment system
work together to achieve the EPA Heavy Duty Diesel
Engine Emissions Standards. These systems are seam-
lessly integrated into your vehicle and managed by the
Cumminst6.7L engine Powertrain Control Module
(PCM). The PCM manages engine combustion to allow
the exhaust system's catalyst to trap and burn Particulate
Matter (PM) pollutants, with no input or interaction on
your part.
Additionally, the overhead console in your vehicle has
the ability to alert you to additional maintenance re-
quired on your truck or engine. Refer to the following
messages that may be displayed on your Electronic
Vehicle Information Center (EVIC):WARNING!
A hot exhaust system can start a fire if you park over
materials that can burn. Such materials might be
grass or leaves coming into contact with your exhaust
system. Do not park or operate your vehicle in areas
where your exhaust system can contact anything that
can burn.
Perform Service
The 6.7L Cumminstengine utilizes a Closed Crankcase
Ventilation (CCV) system, EGR valve and an EGR cooler.
This system filters and recycles gasses produced in the
crankcase during the normal combustion process. ªPer-
form Serviceº will be displayed on the overhead console
of your vehicle if the CCV filter, EGR valve and EGR
cooler are due for required maintenance. The CCV filter is
426 MAINTAINING YOUR VEHICLE

located on the top of the engine valve cover. For addi-
tional information, see your local authorized dealer.
Catalyst Full See Owner Manual
ªCatalyst Full See Owner Manualº will be displayed on
the overhead console of your vehicle if the exhaust
particulate filter reaches 80% of its maximum storage
capacity. Under conditions of exclusive short duration
and low speed driving cycles, your Cumminstengine
and exhaust aftertreatment system may never reach the
conditions required to remove the trapped PM. If this
occurs, ªCatalyst Full See Owner Manualº will be dis-
played on the overhead console in your vehicle. If this
message is displayed you will hear one chime to assist in
alerting you of this condition.
Catalyst Stat::::::::::80%
Catalyst Stat::::::::::80% will replace the message ªCatalyst
Full See Owner Manualº after it is displayed for one
minute. The engine Powertrain Control Module (PCM)will continue to monitor the amount of particulate matter
trapped in the particulate filter. This message indicates
the percentage of the particulate filter capacity that has
been used.
By simply driving your vehicle at highway speeds for as
little as 45 minutes you can remedy the condition in the
particulate filter system and allow your Cumminsten-
gine and exhaust aftertreatment system to remove the
trapped PM and restore the system to normal operating
condition.
Catalyst Stat:::::::::::80%, 90%, 99%
Catalyst Stat:::::::::::80%, 90%, 99% If you are unable to
drive your vehicle under these conditions for an ex-
tended period of time after the initial warning notifica-
tion, the Engine PCM will continue to monitor the
particulate filter and will display the progression of
particulate filter usage (80, 90, 99%) on the EVIC message
center.
MAINTAINING YOUR VEHICLE 427
7

CATALYST FULL SERVICE REQD
If the particulate filter reaches 99% of its capacity, the
overhead console in your vehicle will chime twice and
display the message CATALYST FULL SERVICE REQD.
At this point the engine PCM will register a fault code,
the instrument panel will display a MIL light and the
engine PCM will derate the truck, reducing its horse-
power and torque output.
The PCM derates the engine in order to limit the likeli-
hood of permanent damage to the aftertreatment system.
If this condition is not corrected and a dealer service is
not performed, extensive exhaust aftertreatment damage
can occur. In order to correct this condition it will be
necessary to have the truck serviced by your local
authorized dealer.
Maintenance Free Batteries
The top of the maintenance free batteries are perma-
nently sealed. You will never have to add water, nor is
periodic maintenance required.
NOTE:Replacement batteries should both be of equal
capacity to prevent damage to the vehicle's charging
system.
428 MAINTAINING YOUR VEHICLE

VEHICLE STORAGE
If you are storing your vehicle for more than 21 days, we
recommend that you take the following steps to mini-
mize the drain on your vehicle's battery:
²Disconnect the Ignition-Off Draw fuse (IOD) fuse
located in the Integrated Power Module, located in the
engine compartment. The IOD cavity includes a
snap-in retainer that allows the fuse to be discon-
nected, without removing it from the fuse block.
²The electronic shift transfer case should be placed in
the 4HI mode and kept in this position to minimize the
battery drain.
²As an alternative to the above steps you may discon-
nect the negative cables from both batteries.
²Any time you store your vehicle, or keep it out of
service (i.e., vacation) for two weeks or more, run the
air conditioning system at idle for about five minutesin the fresh air and high blower setting. This will
ensure adequate system lubrication to minimize the
possibility of compressor damage when the system is
started again.
NOTE:When reinstalling the IOD fuse push firmly until
fully seated; the gauges in the instrument cluster will do
a full sweep when the ignition key is cycled to RUN. This
is a normal condition.
NOTE:When the vehicle is shipped from the factory,
the IOD fuse is in the up, or extracted position. If the
radio, interior lamps, keyless entry, or other features do
not work with the key OFF, check the position of the fuse
(or check to see if the fuse is blown) to ensure that it is
fully seated. When the IOD fuse is extracted, the instru-
ment cluster in the odometer window will display9NO
FUSE.º
464 MAINTAINING YOUR VEHICLE

Oil Change Indicator System
Your vehicle is equipped with an engine oil change
indicator system. This system will alert you when it is
time to change your engine oil by displaying the words
ªOil Change Requiredº on your Electronic Vehicle Infor-
mation Center (EVIC). The engine oil change indicator
system is duty cycle based, which means the engine oil
change interval may fluctuate depending on your per-
sonal driving style. Driving styles such as frequent stop
and go type driving can increase the frequency of the
engine oil change. This is the result of more frequent
regeneration of the exhaust aftertreatment system, which
can decrease the life of the engine oil. Failure to change
the engine oil per the maintenance schedule can result in
internal engine damage.
For information on resetting the Oil Change Indicator
message, refer to ªOil Change Required ± If Equipped,ºunder ªSystem Status (EVIC Displays)º in the ªElectronic
Vehicle Information Center (EVIC)º Section of this
manual.
Perform Service Indicator
Your vehicle will require emissions maintenance at a set
interval. To help remind you when this maintenance is
due, the Electronic Vehicle Information Center (EVIC)
will display ªPerform Serviceº. When the ªPerform Ser-
viceº message is displayed on the EVIC it is necessary to
have the emissions maintenance performed. Emissions
maintenance includes replacing the Closed Crankcase
Ventilation (CCV) filter element, cleaning of the EGR
Cooler, and cleaning of the EGR Valve. The procedure for
clearing and resetting the9Perform Service9indicator
message is located in the appropriate Service Informa-
tion.
486 MAINTENANCE SCHEDULES
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