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DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and down-
shifts, and the best fuel economy. The transmission
automatically upshifts through underdrive first, second,
and third gears, direct fourth gear and overdrive fifth and
sixth gears. The DRIVE position provides optimum driv-
ing characteristics under all normal operating conditions.
When frequent transmission shifting occurs (such as
when operating the vehicle under heavy loading condi-
tions, in hilly terrain, traveling into strong head winds, or
while towing heavy trailers), use the Electronic Range
Select (ERS) shift control (refer to “Electronic Range
Select (ERS) Operation” in this section for further infor-
mation) to select a lower gear range. Under these condi-
tions, using a lower gear range will improve performance
and extend transmission life by reducing excessive shift-
ing and heat buildup.If the transmission temperature exceeds normal operat-
ing limits, the powertrain controller will modify the
transmission shift schedule and expand the range of
torque converter clutch engagement. This is done to
prevent transmission damage due to overheating.
If the transmission becomes extremely hot or is in danger
of overheating, the “Transmission Temperature Warning
Light” may illuminate and the transmission may operate
differently until the transmission cools down.
NOTE:
Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer up a steep
grade, or in stop-and-go traffic) during hot weather. In
these conditions, torque converter slip can impose a
significant additional heat load on the cooling system.
Downshifting the transmission to the lowest possible
gear (when climbing a grade), or shifting to NEUTRAL
(when stopped in heavy traffic) can help to reduce this
excess heat generation.
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During cold temperatures, transmission operation may
be modified depending on engine and transmission
temperature as well as vehicle speed. This feature im-
proves warm up time of the engine and transmission to
achieve maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmission fluid
is warm (refer to the “Note” under “Torque Converter
Clutch” in this section). On Pickup models with 68RFE
transmission, top overdrive gear is also inhibited until
the transmission fluid is warm, and during extremely
cold temperatures (-16°F [-27°C] or below), operation
may briefly be limited to first and direct gears only. On
trucks with AS69RC transmission, fifth and sixth gears
may be inhibited briefly on cold starts below 41°F (5°C),
and during very cold temperatures (-4°F [-20°C] or
below), operation may briefly be limited to third gear
only. During this condition, the ability of the vehicle toaccelerate under heavily loaded conditions may be re-
duced. In all cases, normal operation will resume once
the transmission temperature has risen to a suitable level.
Transmission Limp Home Mode
Transmission function is monitored electronically for
abnormal conditions. If a condition is detected that could
result in transmission damage, Transmission Limp Home
Mode is activated. In this mode, the transmission remains
in fourth gear (for 68RFE transmission) or third gear (for
AS69RC transmission) regardless of which forward gear
is selected. If an AS69RC-equipped truck enters Limp
Home Mode at highway speeds, it will initially engage
fifth gear, until the vehicle slows to a speed where third
gear can be engaged. PARK, REVERSE, and NEUTRAL
will continue to operate. The Malfunction Indicator Light
(MIL) may be illuminated. Limp Home Mode allows the
vehicle to be driven to an authorized dealer for service
without damaging the transmission.
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The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pressing the switch a second time restores
normal operation. Normal operation is always the default at
engine start-up. If TOW/HAUL mode is desired, the switch
must be pressed each time the engine is started.
WARNING!
Do not use the “TOW/HAUL” feature when driving
in icy or slippery conditions. The increased engine
braking could cause the rear wheels to slide, and the
vehicle to swing around with the possible loss of
vehicle control, which could cause an accident possi-
bly resulting in personal injury or death.
Torque Converter Clutch
A feature designed to improve fuel economy has been
included in the automatic transmission on your vehicle.
A clutch within the torque converter engages automati-
cally at calibrated speeds. This may result in a slightly
different feeling or response during normal operation in
the upper gears. When the vehicle speed drops or during
some accelerations, the clutch automatically disengages.
TOW/HAUL Switch
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Shifting
Truck models with manual transmission are equipped
with a clutch interlocking ignition system. The clutch
pedal must be fully pressed to start the vehicle.Fully press the clutch pedal before shifting gears. As you
release the clutch pedal, lightly press the accelerator
pedal.
This transmission has a “creeper” first gear which should
be used to start from a standing position when carrying
a payload or towing a trailer. Damage to the clutch can
result from starting in second or third gear with a loaded
vehicle. An unloaded vehicle may be launched in second
gear. Use each gear in numerical order – do not skip a
gear.
NOTE:
When loaded, pulling a trailer or on a grade, the
truck should always start in first gear and not skip gears.
Shift Pattern
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WARNING!
Do not use alcohol or gasoline as a fuel blending
agent. They can be unstable under certain conditions
and hazardous or explosive when mixed with diesel
fuel.
Diesel fuel is seldom completely free of water. To prevent
fuel system trouble, drain the accumulated water from
the fuel/water separator using the fuel/water separator
drain provided on both fuel filters. If you buy good
quality fuel and follow the cold weather advice above,
fuel conditioners should not be required in your vehicle.
If available in your area, a high cetane “premium” diesel
fuel may offer improved cold-starting and warm-up
performance.
CAUTION!
If the “Water in Fuel Indicator Light” remains on, DO
NOT START engine before you drain the water from
the fuel filter(s) to avoid engine damage. Refer to
“Maintenance Procedures/Draining Fuel/Water Sepa-
rator Filter” in “Maintaining Your Vehicle” for fur-
ther information.
Fuel Specifications
The Cummins diesel engine has been developed to take
advantage of the high energy content and generally
lower cost No. 2 Ultra Low Sulfur diesel fuel or No. 2
Ultra Low Sulfur climatized diesel fuels. Experience has
shown that it also operates on No. 1 Ultra Low Sulfur
diesel fuels or other fuels within specification.
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CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
WARNING!
•Never have any smoking materials lit in or near the
vehicle when the fuel door is open or the tank is
being filled.
• Never add fuel when the engine is running. This is
in violation of most state and federal fire regula-
tions and may cause the “Malfunction Indicator
Light” to turn on.
• A fire may result if fuel is pumped into a portable
container that is inside of a vehicle. You could be
burned. Always place fuel containers on the
ground while filling.
ADDING FUEL — CHASSIS CAB MODELS
CAUTION!
To avoid fuel spillage and overfilling, do not “top
off” the fuel tank after filling.
NOTE:
• When the fuel nozzle “clicks” or shuts off, the fuel tank
is full.
• Tighten the fuel filler cap until you hear a “clicking”
sound. This is an indication that the fuel filler cap is
properly tightened.
• Make sure that the fuel filler cap is tightened each time
the vehicle is refueled.
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JUMP STARTING
WARNING!
•To prevent personal injury or damage to clothing,
do not allow battery fluid to contact eyes, skin or
fabrics. Do not lean over a battery when connecting
jumper cables or allow cable clamps to touch each
other. Keep open flames or sparks away from
battery vent holes. Always wear eye protection
when working with batteries.
• Do not use a booster battery or any other booster
source that has a greater than 12 Volt system, i.e., do
not use a 24 Volt power source.
NOTE: Replacement batteries should both be of equal
size to prevent damage to the vehicle’s charging system.
Your vehicle is equipped with two 12 Volt batteries. If it
becomes necessary to use a booster battery with jumper cables to start a vehicle’s engine because its batteries are
discharged, the following procedure should be used:
Set the parking brake and place an automatic transmis-
sion in PARK (or NEUTRAL for a manual transmission).
Turn off lights, heater and other electrical loads. Observe
charge indicator (if equipped) in both batteries. If the
indicator (if equipped) is light or yellow on either battery,
replace that battery.
CAUTION!
Use the jump start procedure only when the charge
indicator (if equipped) in both batteries is dark in the
center. Do not attempt jump starting when either
battery charge indicator (if equipped) is bright or
yellow. If the charge indicator (if equipped) has a
green dot in the center, failure to start is not due to a
discharged battery and cranking system should be
checked.
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second filter location is on the frame behind the front
axle. The best access to this water drain valve is from
under the vehicle.
CAUTION!
•Do not drain the fuel/water separator filters when
the engine is running.
• Diesel fuel will damage blacktop paving surfaces.
Drain the filters into an appropriate container.
If water is detected in the water separator while the
engine is running, or while the ignition switch is in the
ON position, the “Water In Fuel Indicator Light” will
illuminate and an audible chime will be heard five times.
At this point you should stop the engine and drain the
water from both of the filters.
CAUTION!
If the “Water In Fuel Indicator Light” remains on, DO
NOT START the engine before you drain water from
the fuel filters to avoid engine damage.
If the “Water In Fuel Indicator Light” comes on and a
single chime is heard while you are driving, or with the
ignition switch in the ON position, there may be a
problem with your water separator wiring or sensor. See
your authorized dealer for service.
Upon proper draining of the water from both fuel filters,
the “Water In Fuel Indicator Light” will remain illumi-
nated for approximately 10 seconds. If the water was
drained while the engine was running, the “Water In Fuel
Indicator Light” may remain on for approximately three
minutes.
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