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Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. For proper coolant type,
refer to ªRecommended Fluids and Genuine Partsº in
Section 7.
When using the air conditioner in extremely heavy traffic
in hot weather, especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift into
NEUTRAL and depress the accelerator slightly for fast
idle operation to increase coolant flow and fan speed.NOTE:On models equipped with Diesel engines, the
idle speed will automatically increase to 1000 rpm at
elevated coolant temperatures to improve engine cooling.
Your air conditioning system is also equipped with an
automatic recirculation system. When the system senses
a heavy load or high heat conditions, it may use partial
Recirculation A/C mode to provide additional comfort.
Winter Operation
When operating the system during the Winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
UNDERSTANDING YOUR INSTRUMENT PANEL 261
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STARTING PROCEDURES ± DIESEL ENGINES
Before starting your vehicle, adjust your seat, adjust both
inside and outside mirrors, and fasten your seat belts.
The starter should not be operated for more than 15-
second intervals. Waiting a few minutes between such
intervals will protect the starter from overheating.
WARNING!
Be sure to turn off the engine and remove the key
from the ignition switch if you want to rest or sleep
in your vehicle. Accidents can be caused by inadvert-
ently moving the shift lever or by pressing the
accelerator pedal. This may cause excessive heat in
the exhaust system, resulting in overheating and
vehicle fire which may cause serious or fatal injuries.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build up may
cause serious injury or death.
Automatic Transmission ± If Equipped
Start the engine with the shift lever in NEUTRAL or
PARK position. Apply the brake before shifting to any
driving range.
The CumminstDiesel engine is equipped with several
features designed to assist cold weather starting and
operation:
²The engine block heater is a resistance heater installed
in the water jacket of the engine just above and behind
the oil filter. It requires a 110±115 volt AC electrical
outlet with a grounded, three-wire extension cord.
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CAUTION!
If WATER IN FUEL indicator light remains on DO
NOT START engine before you drain water from the
fuel filter to avoid engine damage. Refer to ªDrain-
ing Fuel/Water Separator Filter (6.7L Diesel Engine)º
under ªMaintenance Proceduresº in Section 7.
4. Turn the ignition key to START and crank the engine.
Do not press the accelerator during starting.
CAUTION!
Do not crank engine for more than 15 seconds at a
time as starter motor damage may result. Turn key to
OFF and wait at least two minutes before trying
again.5. When the engine starts, release the key.
6. Check to see that there is oil pressure.
7. Release the parking brake.
Starting Procedure ± Engine Manifold Air
Temperature Below 66ÉF (19ÉC)
NOTE:The temperature displayed on the overhead
console (if equipped) does not necessarily reflect the
engine manifold air temperature. When certain engine
temperatures fall below 66ÉF (19ÉC) the lights will remain
on indicating the intake manifold heater system is active.
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Follow the steps in the Normal Starting Procedure ex-
cept:
CAUTION!
Do not crank engine for more than 15 seconds at a
time or starter motor damage may result. Turn key to
OFF and wait at least two minutes for starter to cool
before repeating start procedure.
²The WAIT TO START light will remain on for a period
of time (length of time depends on engine tempera-
ture).
²After the WAIT TO START light goes off, turn the
ignition key to START. Do not press the accelerator
during starting.
²After engine start-up, check to see that there is oil
pressure.
²Allow the engine to idle about three minutes until
the manifold heaters have completed the post-heat
cycle.
²Release the parking brake and drive.
NOTE:Engine idle speed will automatically increase to
1000 RPM at low coolant temperatures to improve engine
warm-up.
NOTE:If the engine stalls or if the ignition switch is left
ON for more than two minutes after the WAIT TO START
light goes out, reset the grid heaters by turning the
ignition switch to OFF for at least five seconds and then
back ON. Repeat steps 3 through 7 of the normal starting
procedure.
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Starting Fluids
WARNING!
STARTING FLUIDS or flammable liquids are
NEVER TO BE USED in the CumminstDiesel (see
Warning label). Never pour diesel fuel, flammable
liquid, starting fluids (ether) into the air cleaner
canister, air intake piping, or turbocharger inlet in an
attempt to start the vehicle. This could result in a
flash fire and explosion causing serious personal
injury and engine damage.
The engine is equipped with an automatic electric air
preheating system. If the instructions in this manual are
followed, the engine should start in all conditions.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build up may
cause serious injury or death.
NORMAL OPERATION (DIESEL ENGINE)
Observe the following when the engine is operating.
²All message center lights are off.
²Check Engine Lamp is off.
²Engine Oil Pressure is above 10 psi (69 kPa) at idle.
²Low Oil Pressure light is off.
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Block Heater Usage
A.Temperatures below 0ÉF (-18ÉC)
²Block Heater Required for 15W-40
²Block Heater Recommended for 5W-40
B.Temperatures below - 20ÉF (-29ÉC)
²Block Heater Required for 5W-40
Winter Front Usage
If a winter front or cold weather cover is to be used, a
percentage of the total grille opening area must be left
uncovered to provide sufficient air flow to the charge air
cooler and automatic transmission oil cooler. The per-
centage of opening must be increased with the increasing
ambient air temperature and/or engine load. If the
cooling fan can be heard cycling frequently, increase the
size of the opening in the winter front. A suitable cold
weather cover is available from your Mopartdealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0ÉF (-18É). For the same de-
crease in temperature, the engine requires twice as much
power to crank at the same RPM. The use of 120 VAC
powered battery blankets will greatly increase starting
capability at low temperatures. Suitable battery blankets
are available from your authorized Mopartdealer.
Arctic Operation
Where there are no provisions to keep the engine warm
when it is operating in ambient temperatures consistently
below (-10ÉF/-23ÉC), use 5W-40syntheticengine oil and
fuel that meets the requirements in Section 7, ªMainte-
nance Procedures,º Engine Oil Selection.
Engine Warm-Up
Avoid full throttle operation when the engine is cold.
When starting a cold engine, bring the engine up to
operating speed slowly to allow the oil pressure to
stabilize as the engine warms up.
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NOTE:High-speed, no-load running of a cold engine
can result in excessive white smoke and poor engine
performance. No-load engine speeds should be kept
under 1,200 rpm during the warm-up period, especially
in cold ambient temperature conditions.
If temperatures are below 32ÉF (0ÉC), operate the engine
at moderate speeds for 5 minutes before full loads are
applied.
Engine Idling
Avoid prolonged idling, long periods of idling may be
harmful to your engine because combustion chamber
temperatures can drop so low that the fuel may not burn
completely. Incomplete combustion allows carbon and
varnish to form on piston rings and injector nozzles.
Also, the unburned fuel can enter the crankcase, diluting
the oil and causing rapid wear to the engine.
CAUTION!
Extended periods of idle time may not allow the
vehicle's exhaust aftertreatment system to properly
regenerate. This can lead to the illumination of the
Malfunction Indicator Light (MIL) or an Electronic
Vehicle Information Center (EVIC) warning message.
Operating the engine for extended periods with the
MIL illuminated or an EVIC warning message dis-
played can cause extensive engine and exhaust sys-
tem damage.
NOTE:Your vehicle is equipped with a turbo speed
limiter, this feature limits the engine speed to 1200 rpm
when engine coolant temperatures are below 70ÉF (21ÉC).
This feature is designed to protect the turbo charger from
damage and will only operate in PARK or NEUTRAL.
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Stopping The Engine
Idle the engine a few minutes before routine shutdown.
After full load operation, idle the engine 3 to 5 minutes
before shutting it down. This idle period will allow the
lubricating oil and coolant to carry excess heat away from
the combustion chamber, bearings, internal components,
and turbocharger. This is especially important for turbo-
charged, charge air cooled engines.
NOTE:During engine shutdown on vehicles equipped
with manual transmissions, it is normal for the diesel
engine to resonate heavily for a moment during engine
shut off. When the engine is connected to a manual
transmission, this resonance causes loud gear rattle from
the transmission. This is commonly referred to as ªshut
down rattleº. The manufacturer recommends performing
engine shut down with the clutch pedal pushed to the
floor (clutch disengaged). When engine shut down is
performed in this manner the rattle is reduced (not
eliminated).Driving
ConditionLoadTurbo-
charger
TemperatureIdle Time
(min.) Be-
fore Engine
Shutdown
Stop and
GoEmpty Cool Less than
One
Stop and
GoMedium One
Highway
SpeedsMedium Warm Two
City Traffic Maximum
GCWRThree
Highway
SpeedsMaximum
GCWRFour
Uphill
GradeMaximum
GCWRHot Five
280 STARTING AND OPERATING