
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. 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 to
238 STARTING AND OPERATING

accelerate 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.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.
3. Turn the ignition switch to the OFF position.
4. Wait approximately 10 seconds.
5. Restart the engine.
6. Shift into the desired gear range. If the problem is no
longer detected, the transmission will return to normal
operation.
NOTE: Even if the transmission can be reset, we recom-
mend that you visit your authorized dealer at your
earliest possible convenience. Your authorized dealer has
diagnostic equipment to determine if the problem could
recur.
4
STARTING AND OPERATING 239

•The engine coolant has reached an adequate tempera-
ture.
• The vehicle speed is sufficiently high.
• The driver is not heavily pressing the accelerator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying a
heavy load, etc., and frequent transmission shifting oc-
curs, press the TOW/HAUL switch to activate TOW/
HAUL mode. This will improve performance and reduce
the potential for transmission overheating or failure due
to excessive shifting. When operating in TOW/HAUL
mode, transmission upshifts are delayed, and the trans-
mission will automatically downshift (for engine brak-
ing) when the throttle is closed and/or during steady
braking maneuvers.
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.
TOW/HAUL Switch
242 STARTING AND OPERATING

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.
Maximum Recommended Up-Shift Speeds
Gear Selection 1 to 2 2 to 33 to 44 to 5 5 to 6
Maximum Speed 7 mph
(11 km/h) 15 mph
(24 km/h) 25 mph
(40 km/h) 40 mph
(64 km/h) 45 mph
(72 km/h)
4
STARTING AND OPERATING 245

AS69RC Six-Speed Automatic Transmission Only
The PTO drive gear (part of the AS69RC) operates at
torque converter turbine speed. The turbine speed will be
less than engine speed when the torque converter clutch
is not engaged and will be same as engine speed when
the torque converter clutch is engaged.
Stationary Mode
To operate the PTO in this mode the vehicle must meet
the following conditions:
•Be in PARK position (vehicles equipped with auto-
matic transmission.)
• PTO switch has been activated.
• Parking brake applied (vehicles equipped with
manual transmission).
• Brake pedal must not be applied.
• Vehicle engine must be running. •
No vehicle, brake or clutch switch faults present.
• PTO must be correctly installed using the vehicle
provided circuits.
The Electronic Vehicle Information Center (EVIC) or
Driver Information Display (DID) will display a PTO
On message for five seconds if the above conditions are
met. Otherwise, the EVIC/DID will display a message
To Operate PTO Shift To Park indicating what operator
action should be taken to engage the PTO mode.
The customer has the choice to operate the PTO by
utilizing the cruise control switches or by utilizing a
remote control (provided by the PTO supplier). To oper-
ate the feature using the cruise control switches, the
customer must first activate the PTO switch which will
turn on the PTO. In order to increase or decrease the
engine idle speed, to optimize the PTO function, the
“RESUME/ACCEL” and “DECEL” cruise switches can
4
STARTING AND OPERATING 249

NOTE:
•If you accidentally fill the fuel tank with gasoline on
your diesel vehicle, Do not start the vehicle. If you
restart your vehicle you risk damaging the engine and
fuel system. Please call your local dealer for service.
• A maximum blend of 5% biodiesel meeting ASTM
specification D-975 may be used with your Cummins®
diesel engine. (Chassis Cab models not configured
with B20 capability.)
• A maximum blend of 20% biodiesel meeting ASTM
specification D-7467 may be used with your Cum-
mins® diesel engine. (Pickup models and Chassis Cab
models configured with B20 Capability.)
• In addition, commercially available fuel additives are
not necessary for the proper operation of your Cum-
mins® diesel engine. However, if seasonably adjusted
fuel is not available and you are operating below 20°F (-6°C), Mopar® Premium Diesel Fuel Treatment (or
equivalent) may be beneficial to avoid fuel gelling.
• No. 1 Ultra Low Sulfur diesel fuel should only be used
where extended arctic conditions (-10°F or -23°C) exist.
Bio-Diesel Fuel Requirements
Chassis Cab Models
A maximum blend of 5% biodiesel meeting ASTM speci-
fication D975 may be used with your Cummins diesel
engine. If operation with Biodiesel blends greater than
5% but not greater than 20% (B6-B20) is desired, the truck
must first be reconfigured by an authorized Ram dealer
and the provisions in the following section must be
adhered to.
254 STARTING AND OPERATING

Engine Air Cleaner Filter Installation
NOTE:Inspect and clean the housing if dirt or debris is
present before replacing the air filter element.
1. Install the air cleaner filter element into the housing assembly with the air cleaner filter inspection surface
facing downward.
2. Install the air cleaner cover onto the housing assembly locating 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 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.
288 MAINTAINING YOUR VEHICLE

CAUTION!
Due to lack of lubricants in alcohol or gasoline, the
use of these fuels can cause damage to the fuel
system.
NOTE:
• A maximum blend of 5% biodiesel, meeting ASTM
specification D-975 may be used with your Cummins®
diesel engine. (Chassis Cab models not configured
with B20 capability.)
• A maximum blend of 20% biodiesel, meeting ASTM
specification D-7467 may be used with your Cum-
mins® diesel engine. (Pickup models and Chassis Cab
models configured with B20 capability.) •
Use of biodiesel mixture in excess of 20% can nega-
tively impact the fuel filter’s ability to separate water
from the fuel, resulting in high pressure fuel system
corrosion or damage.
• Ethanol blends are not recommended or approved for
use with your Cummins® diesel engine.
• In addition, commercially available fuel additives are
not necessary for the proper operation of your Cum-
mins® diesel engine.
Intervention Regeneration Strategy — Message
Process Flow
The Cummins® diesel engine meets all EPA Heavy Duty
Diesel Engine Emissions Standards, resulting in one of
the lowest emitting diesel engines ever produced.
6
MAINTAINING YOUR VEHICLE 295