CAUTION!• During the first 500 miles (805 km) your new
vehicle is driven, do not tow a trailer. Doing so
may damage your axles, driveline and vehicle.
• Limit your speed to 50 mph (80 km/h) during the
first 500 miles (805 km) of towing.
6.7L Diesel Engine
Your Cummins 24 Valve Turbo Diesel engine does not
require a break-in period due to its construction. Normal
operation is allowed, provided the following recommen-
dations are followed:
NOTE: Light duty operation such as light trailer towing
or no load operation, will extend the time before the
engine is at full efficiency and may effect the performance
of the vehicle aftertreatment (exhaust) system. Reduced
fuel economy and power may be seen at this time. • Warm up the engine before placing it under load.
• Do not operate the engine at idle for prolonged
periods.
• 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.
Because of the construction of the Cummins 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). THINGS TO KNOW BEFORE STARTING YOUR VEHICLE 73
2
INSTRUMENT CLUSTER DESCRIPTION
1. Check Gages
This light illuminates when the Voltmeter, Engine
Oil Pressure or Engine Coolant Temperature
gages indicate a reading either too high or too low.
Examine the gages carefully, and follow the instructions
above for each indicated problem.
NOTE: When the ignition switch is turned to OFF, the
Fuel Gage, Voltmeter, Oil Pressure and Engine Coolant
Temperature gages may not show accurate readings.
When the engine is not running, turn the ignition switch
to ON to obtain accurate readings.
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 sys-
tem should be serviced.
NOTE: If the gauge pointer moves to either extreme of
the gauge, the “Check Gages” indicator will illuminate
and a single chime will sound.
NOTE:
• The voltmeter may show a gauge fluctuation if certain
engine temperatures are below 66°F (19°C). This cy-
cling 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, this time will not exceed
150 seconds. The needle should then stabilize at the
approximate operation point.
• The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a noticeable
reduction in blower motor speed.172 UNDERSTANDING YOUR INSTRUMENT PANEL
9. 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. (See page 398 for more
information.)
NOTE: If the gauge pointer moves to either extreme of
the gauge, the “Check Gages” indicator will illuminate
and a single chime will sound.
10. Transfer Case Position
(See page 283 for more information.)
11 . TOW HAUL
The TOW HAUL button is located at the end of the gear
shift lever. This light will illuminate when the TOW
HAUL OD/OFF button is pushed once. (See page 271 for
more information.) 12. OD/OFF
the OD/OFF button is located at the end of the gear shift
lever. This light will illuminate when the TOW HAUL
OD/OFF button is pushed twice. (See page 271 for more
information.)
13. Temperature Gauge
The temperature gauge indicates engine coolant
temperature. Any reading within the normal
range indicates that the cooling system is operat-
ing satisfactorily. The gauge needle will likely indicate a
higher temperature when driving in hot weather, up
mountain grades, in heavy traffic, or when towing a
trailer. If the needle rises to the “245°F” mark, stop the
vehicle, shift into N (Neutral), and increase the engine
idle speed for 2 to 3 minutes. If the temperature reading
does not return to normal, shut your engine OFF and
allow it to cool. Seek authorized service immediately. See
Cooling System information in the section on “Maintain-
ing Your Vehicle.”174 UNDERSTANDING YOUR INSTRUMENT PANEL
a manual transmission. Models with manual transmis-
sion are equipped with a clutch interlocking cranking
system. The clutch must be fully depressed to start the
vehicle.
3. Turn the ignition key to the ON position and look at
the instrument panel cluster lamps.
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. See Section 7 —
Maintaining Your Vehicle, for water drain proce-
dures.
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 66°F (19°C)
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 66°F (19°C) the lamp will remain
on indicating the intake manifold heater system is active. STARTING AND OPERATING 253
5
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 2 minutes for starter to cool
before repeating start procedure.
• The WAIT TO START light will remain on for a period
of time (length of time depends on engine tempera-
ture).
• After the WAIT TO START light goes off, turn the
ignition key to START. Do not press the accelerator
during starting.
• After engine start-up, check to see that there is oil
pressure. • Allow the engine to idle about three minutes until
the manifold heaters have completed the post-heat
cycle.
• Release 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 2 minutes after the WAIT TO START
light goes out, reset the grid heaters by turning the
ignition switch to Off for at least 5 seconds and then back
On. Repeat steps 3 through 7 of the normal starting
procedure.
For Extremely Cold Weather Starting — Engine
Manifold Air Temperature Below 0°F (- 18°C)
In extremely cold weather below 0°F (- 18°C) it may be
beneficial to cycle the manifold heaters twice before254 STARTING AND OPERATING
Starting Fluids
WARNING!STARTING FLUIDS or flammable liquids are
NEVER TO BE USED in the Cummins Diesel (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.
• All message center lights are off.
• Check Engine Lamp is off.
• Engine Oil Pressure is above 10 psi (69 kPa) at idle.
• Low Oil Pressure light is off.
• Voltmeter Operation:
• The voltmeter may show a gauge fluctuation if
certain engine temperatures are below 66°F (19°C).
This cycling operation is caused by the post-heat STARTING AND OPERATING 257
5
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 Mopar dealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the battery
temperature decreases to 0°F (-18°). 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 Mopar dealer. Arctic Operation
Where there are no provisions to keep the engine warm
when it is operating in ambient temperatures consistently
below (-10°F/-23°C), use 5W-40 synthetic engine oil and
fuel that meets the requirements in Section 7, “Mainte-
nance Procedures,” 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.
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.260 STARTING AND OPERATING
• Up Steep Hills —
select a lower transmission gear, but try and keep the
torque converter clutch engaged.
• Air Conditioning —
turn it off temporarily.
Do Not Operate The Engine With Low Oil
Pressure
When the engine is at normal operating temperature, the
minimum oil pressures required are:
Idle 700 to 800 RPM ............... 10psi(69kPa)
Full speed and load .............. 30psi (207 kPa)
CAUTION!If oil pressure falls to less than normal readings, shut
the engine off immediately. Failure to do so could
result in immediate and severe engine damage. Do Not Operate The Engine With Failed Parts
Practically all failures give some warning before the parts
fail. Be on the alert for changes in performance, sounds,
and visual evidence that the engine requires service.
Some important clues are:
• engine misfiring or vibrating severely
• sudden loss of power
• unusual engine noises
• fuel, oil or coolant leaks
• sudden change, outside the normal operating range, in
the engine operating temperature
• excessive smoke
• oil pressure drop264 STARTING AND OPERATING