WARNING!
Do not coast in NEUTRAL and never turn off the
ignition to coast down a hill. These are unsafe practices
that limit your response to changing traffic or road
conditions. You might lose control of the vehicle and
have a collision.
CAUTION!
Towing the vehicle, coasting, or driving for any other
reason with the transmission in NEUTRAL can cause
severe transmission damage. Refer to “Recreational
Towing” in “Starting And Operating” and “Towing A
Disabled Vehicle” in “What To Do In Emergencies” for
further information.
DRIVE (D)
This range should be used for most city and highway
driving. It provides the smoothest upshifts and downshifts,
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 driving characteristics
under all normal operating conditions. When frequent transmission shifting occurs (such as when
operating the vehicle under heavy loading conditions, in
hilly terrain, traveling into strong head winds, or while
towing a heavy trailer), use the Electronic Range Select
(ERS) shift control (refer to “Electronic Range Select (ERS)
Operation” in this section for further information) to select
a lower gear range. Under these conditions, using a lower
gear range will improve performance and extend transmis-
sion life by reducing excessive shifting and heat buildup.
If the transmission temperature exceeds normal operating
limits, the powertrain controller will modify the transmis-
sion shift schedule and expand the range of torque con-
verter clutch engagement. This is done to prevent trans-
mission 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.
5
STARTING AND OPERATING 145
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 sig-
nificant additional heat load on the cooling system. Down-
shifting 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.
During cold temperatures, transmission operation may be
modified depending on engine and transmission tempera-
ture as well as vehicle speed. This feature improves warm
up time of the engine and transmission to achieve maxi-
mum 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 sec-
tion). 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 transmis-
sion, 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 to accelerate under heavily loaded conditions may
be reduced. 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 ab-
normal 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 damag-
ing the transmission.
In the event of a momentary problem, the transmission can
be reset to regain all forward gears by performing the
following steps:
1. Stop the vehicle.
2. Shift the transmission into PARK.
146 STARTING AND OPERATING
will automatically downshift (for engine braking) when the
throttle is closed and/or during steady braking maneu-
vers.
The “TOW/HAUL Indicator Light” will illuminate in the
instrument cluster to indicate that TOW/HAUL mode has
been activated. Pushing 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 pushed each time the engine is started.WARNING!
Do not use the “TOW/HAUL” feature when driving in
icy or slippery conditions. The increased engine brak-
ing can cause the rear wheels to slide, and the vehicle
to swing around with the possible loss of vehicle
control, which may cause an accident possibly result-
ing 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 automatically
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
5
STARTING AND OPERATING 149
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.
Recommended Vehicle Shift Speeds
To utilize your manual transmission efficiently for both
fuel economy and performance, it should be upshifted as
listed in recommended shift speed chart. Shift at the
vehicle speeds listed for acceleration. When heavily loaded
or pulling a trailer these recommended up-shift speeds
may not apply.
Shift Pattern
5
STARTING AND OPERATING 151
FUEL REQUIREMENTS
Use good quality diesel fuel from a reputable supplier in
your vehicle. Federal law requires that you must fuel this
vehicle with Ultra Low Sulfur Highway Diesel fuel (15
ppm Sulfur maximum) and prohibits the use of Low Sulfur
Highway Diesel fuel (500 ppm Sulfur maximum) to avoid
damage to the emissions control system.
For most year-round service, No. 2 diesel fuel meeting
ASTM (formerly known as the American Society for Test-
ing and Materials) specification D-975 Grade S15 will
provide good performance. If the vehicle is exposed to
extreme cold (below 20°F or -7°C), or is required to operate
at colder-than-normal conditions for prolonged periods,
use climatized No. 2 diesel fuel or dilute the No. 2 diesel
fuel with 50% No. 1 diesel fuel. This will provide better
protection from fuel gelling or wax-plugging of the fuel
filters.
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 condition-
ers 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 further
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.
5
STARTING AND OPERATING 157
NOTE:Ensure funnel is inserted fully to hold flapper door
open.
3. Pour fuel into funnel opening.
4. Remove funnel from filler pipe, clean off prior to putting back in the jack kit.
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 regulations
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.
Emergency Fuel Fill Location
162 STARTING AND OPERATING
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 work-
ing 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 transmission
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 light or yel-
low. 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.
1. Attach one jumper cable to the positive terminal of booster battery and the other end of the same cable to
the positive terminal of the discharged battery.
NOTE: Do not connect jumper cables to the fuses. Only
use the jump post when connecting jumper cables.
WARNING!
Do not permit vehicles to touch each other as this could
establish a ground connection and personal injury
could result.
170 WHAT TO DO IN EMERGENCIES
2. Install the air cleaner cover onto the housing assemblylocating tabs.
3. Install screws to secure the air cleaner cover to the housing assembly.
Draining Fuel/Water Separator Filter
There are two fuel filter assemblies. One is located on the
driver’s side of the engine. The best access to this water
drain valve is from under the hood. The second one is on
the under body, located in front of the rear axle above the
drive shaft on pick-up models. The Chassis Cab models
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 filter when the
engine is running.
• Diesel fuel will damage blacktop paving surfaces.
Drain the filter 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 illumi-
nate 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 illuminated
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.
NOTE: Care should be taken in disposing of used fluids
from your vehicle. Used fluids, indiscriminately discarded,
can present a problem to the environment. Contact an
authorized dealer, service station, or government agency
for advice on recycling programs and for where used fluids
and filters can be properly disposed of in your area.
184 MAINTAINING YOUR VEHICLE