2023 RAM CHASSIS CAB heating

STARTING AND OPERATING121
(Continued)
STARTING PROCEDURE — ENGINE
M
ANIFOLD AIR TEMPERATURE BELOW
0°F (-18°C)
In extremely cold weather below 0°F (-18°C) it
may be beneficial to cycle the intake air heater
twice before attempting to start the engine. This
can be accomplished by turning the ignition to OFF
position for at least five seconds and then back to
the ON/RUN position after the Wait To Start
Indicator Light has turned off, but before the
engine is started. However, excessive cycling of the
intake air heater will result in damage to the heater
elements or reduced battery voltage.
NOTE:If multiple pre-heat cycles are used before starting,
additional engine run time may be required to
maintain battery state of charge at a satisfactory
level.

1. If the engine stalls after the initial start, the
ignition must be turned to the OFF position for
at least five seconds and then to the ON/RUN
position to recycle the intake air heater.

NOTE:Excessive white smoke and poor engine perfor -
mance will result if intake air heater is not recycled.
2. Heat generated by the intake air heater dissipates rapidly in a cold engine. If more than
two minutes pass between the time the Wait To Start Indicator Light turns off and the
engine is started, recycle the intake air heater
by turning the ignition switch to the OFF
position for at least five seconds and then
back to the ON/RUN position.
3. If the vehicle is driven and vehicle speed exceeds 19 mph (31 km/h) before the intake
air heater post-heat (after start) cycle is
complete, the intake air heater will shut off.
4. If the engine is cranked for more than 10 seconds, the post-heat cycle will turn off.
NOTE:
Engine idle speed will automatically increase to
1,000 RPM and engage the Variable Geometry
Turbocharger at low coolant temperatures to
improve engine warm-up.
When a diesel engine is allowed to run out of
fuel or the fuel gels at low temperatures, air is
pulled into the fuel system. If your engine has
run out of fuel Ú page 363.
If the engine stalls, or if the ignition switch is left
on for more than two minutes after the Wait To
Start Indicator Light goes out, reset the intake
air heater by turning the ignition switch to the
OFF position for at least five seconds and then
back to the ON/RUN position. Repeat steps 1
through 5 of “Starting Procedure – Engine Mani -
fold Air Temperature 0°F to 60°F (-18°C to
19°C).”
STARTING FLUIDS
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!
Starting fluids or flammable liquids must never
be used in the Cummins® diesel engine (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.
WARNING!
Do not leave children or animals inside parked
vehicles in hot weather. Interior heat build-up
may cause serious injury or death.
When leaving the vehicle, always remove the
key fob and lock your vehicle.
4

23_DPF_OM_EN_USC_t.book Page 121

126STARTING AND OPERATING
PROGRAMMABLE MAXIMUM VEHICLE
S
PEED
This feature allows the owner to set a maximum
vehicle speed for the vehicle. The 2500 and 3500
Series maximum vehicle speed can be set
between 40 mph to 87 mph (64 km/h to
140 km/h). The 4500/5500 Series maximum
vehicle speed can be set between 40 mph to
85 mph (64 km/h to 136 km/h). See an
authorized dealer to enable this feature.
NOTE:DO NOT set the maximum vehicle speed to a value
greater than what the vehicle tires are rated for.
OPERATING PRECAUTIONS
Avoid Overheating The Engine
The temperature of the engine coolant (antifreeze:
a mixture of 50% ethylene-glycol and 50% water)
must not exceed the normal range of the
temperature gauge 240°F (116°C) with a 21 psi
(145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze)
temperature indicated during operation will be to
the left of center in the normal range of the gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant
(antifreeze) temperature below the normal range
on the gauge 140°F (60°C) can be harmful to the engine. Low engine coolant (antifreeze)
temperature can cause incomplete combustion
which allows carbon and varnish to form on piston
rings and injector nozzles. Also, the unburned fuel
can enter the crankcase, diluting the lubricating oil
and causing rapid wear to the engine.
COOLING SYSTEM TIPS
To reduce potential for engine and transmission
overheating in high ambient temperature
conditions, take the following actions:
City Driving — When stopped, shift the transmis
-
sion into NEUTRAL and increase engine idle
speed.
Highway Driving — Reduce your speed.
Up Steep Hills — Select a lower transmission
gear.
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:
Do Not Operate The Engine With Failed
Parts
All engine 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 drop.
Idle 700 to 800 RPM 10 psi (69 kPa)
Full speed and load 30 psi (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.

23_DPF_OM_EN_USC_t.book Page 126

134STARTING AND OPERATING
engine shutdown, perform this procedure only in a
desired location (preferably, at an authorized
dealer).

1. Stop the vehicle.

2. Shift the transmission into PARK, if possible. If not, shift the transmission to NEUTRAL.
3. Push and hold the ignition switch until the engine turns off.
4. Wait approximately 30 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
recommend that you visit an authorized dealer at
your earliest possible convenience. An authorized
dealer has diagnostic equipment to assess the
condition of your transmission.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The ERS shift control allows the driver to limit the
highest available gear when the transmission is in
DRIVE. For example, if you set the transmission
gear limit to FOURTH gear, the transmission will not shift above FOURTH gear (except to prevent
engine overspeed), but will shift through the lower
gears normally.
You can switch between DRIVE and ERS mode at
any vehicle speed. When the transmission gear
selector is in DRIVE, the transmission will operate
automatically, shifting between all available gears.
Tapping the GEAR “–” switch (on the steering
wheel) will activate ERS mode, display the current
gear in the instrument cluster, and set that gear as
the top available gear. Once in ERS mode, tapping
the GEAR “–” or GEAR “+” switch will change the
top available gear.

ERS Control
To exit ERS mode, simply push and hold the
GEAR “+” switch until the gear limit display
disappears from the instrument cluster.
When to Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying
a heavy load, etc., and frequent transmission
shifting occurs, push 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.

TOW/HAUL Switch

1 — GEAR “+” Switch
2 — GEAR “–” Switch
WARNING!
Do not downshift for additional engine braking
on a slippery surface. The drive wheels could
lose their grip and the vehicle could skid,
causing a collision or personal injury.

23_DPF_OM_EN_USC_t.book Page 134

STARTING AND OPERATING137
If the transmission temperature exceeds normal
operating 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 improves 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 Ú page 139. On trucks with AS66RC or 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 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 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 THIRD gear
regardless of which forward gear is selected. If an
AS66RC/AS69RC equipped truck enters
Transmission 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. Transmission 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 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
recommend that you visit an authorized dealer at
your earliest possible convenience. An authorized
dealer has diagnostic equipment to assess the
condition of your transmission.
If the transmission cannot be reset, authorized
dealer service is required.
Electronic Range Select (ERS) Operation
The ERS shift control allows the driver to limit the
highest available gear when the transmission is in
DRIVE. For example, if you set the transmission
gear limit to FOURTH gear, the transmission will
not shift above FOURTH gear, but will shift through
the lower gears normally.
4

23_DPF_OM_EN_USC_t.book Page 137

138STARTING AND OPERATING
You can switch between DRIVE and ERS mode at
any vehicle speed. When the gear selector is in the
DRIVE position, the transmission will operate
automatically, shifting between all available gears.
Tapping the ERS “-” switch will activate ERS mode,
display the current gear in the instrument cluster,
and set that gear as the top available gear. Once in
ERS mode, tapping “-” or “+” will change the top
available gear.

Electronic Range Select

To exit ERS mode, simply push and hold the
ERS “+” switch until the gear limit display
disappears from the instrument cluster.
NOTE:To select the proper gear position for maximum
deceleration (engine braking), simply push and
hold the ERS “-” switch. The transmission will shift
to the range from which the vehicle can best be
slowed down.
Overdrive Operation

The automatic transmission includes an
electronically controlled Overdrive (FIFTH and SIXTH
gears). The transmission will automatically shift into
Overdrive if the following conditions are present:

The gear selector is in the DRIVE position.
The transmission fluid has reached an
adequate temperature.
The engine coolant has reached an adequate
temperature.
Vehicle speed is sufficiently high.
The TOW/HAUL switch has not been activated.
The driver is not heavily pressing the acceler -
ator.
When To Use TOW/HAUL Mode
When driving in hilly areas, towing a trailer, carrying
a heavy load, etc., and frequent transmission
shifting occurs, push 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
transmission will automatically downshift (for
engine braking) when the throttle is closed and/or
during steady braking maneuvers.

TOW/HAUL Switch

1 — GEAR “+” Switch
2 — GEAR “–” Switch
WARNING!
Do not downshift for additional engine braking
on a slippery surface. The drive wheels could
lose their grip and the vehicle could skid,
causing a collision or personal injury.
CAUTION!
When using ERS for engine braking while
descending steep grades, be careful not to
overspeed the engine. Apply the brakes as
needed to prevent engine overspeed.

23_DPF_OM_EN_USC_t.book Page 138

180STARTING AND OPERATING
(Continued)
Refilling With Containers
Proceed as follows:
Check the expiration date.

Read the advice for use on the label before
pouring the content of the bottle into the DEF tank.

After the indication appears on the instrument
cluster display
Úpage 89 fill the DEF tank with
no more than 6 gal (22 L).
Stop filling the DEF tank immediately if DEF
splashes or wells back in the filler neck.
Reinstall cap onto DEF filler tube.
Filling The Def Tank In Cold Climates
Since DEF will begin to freeze at 12°F (-11°C),
your vehicle is equipped with an automatic DEF
heating system. This allows the DEF injection
system to operate properly at temperatures below
12°F (-11°C). If your vehicle is not in operation for
an extended period of time with temperatures
below 12°F (-11°C), the DEF in the tank may
freeze. If the tank is overfilled and freezes, it could
be damaged. Therefore, do not overfill the DEF
tank. Extra care should be taken when filling with
portable containers to avoid overfilling. Note the
level of the DEF gauge in your instrument cluster.
You may safely add a maximum of 2 gal (7.5 L) of
DEF from portable containers when your DEF
gauge is reading ½ full.VEHICLE LOADING
GROSS VEHICLE WEIGHT RATING
(GVWR)
The GVWR is the total permissible weight of your
vehicle including driver, passengers, vehicle,
options and cargo. The label also specifies
maximum capacities of front and rear axle systems
(GAWR). Total load must be limited so GVWR and
front and rear GAWR are not exceeded.
PAYLOAD
The payload of a vehicle is defined as the allowable
load weight a truck can carry, including the weight
of the driver, all passengers, options and cargo.
GROSS AXLE WEIGHT RATING (GAWR)
The GAWR is the maximum permissible load on the
front and rear axles. The load must be distributed
in the cargo area so that the GAWR of each axle is
not exceeded.
CAUTION!
To avoid DEF spillage, and possible damage to
the DEF tank from overfilling, do not “top off”
the DEF tank after filling.
DO NOT OVERFILL. DEF will freeze below 12ºF
(-11ºC). The DEF system is designed to work in
temperatures below the DEF freezing point,
however, if the tank is overfilled and freezes,
the system could be damaged.
When DEF is spilled, clean the area immedi -
ately with water and use an absorbent mate -
rial to soak up the spills on the ground.
Do not attempt to start your engine if DEF is
accidentally added to the diesel fuel tank as it
can result in severe damage to your engine,
including but not limited to failure of the fuel
pump and injectors.

Never add anything other than DEF to the
tank – especially any form of hydrocarbon
such as diesel fuel, fuel system additives,
gasoline, or any other petroleum-based
product. Even a very small amount of these,
less than 100 parts per million or less than
1 oz. per 78 gal (295 L) will contaminate the
entire DEF system and will require replace -
ment. If owners use a container, funnel or
nozzle when refilling the tank, it should either
be new or one that has only been used for
adding DEF. Mopar® provides an attachable
nozzle with its DEF for this purpose.

CAUTION!

23_DPF_OM_EN_USC_t.book Page 180

192STARTING AND OPERATING
TOWING TIPS
Before setting out on a trip, practice turning,
stopping, and backing up the trailer in an area
located away from heavy traffic.
Automatic Transmission

The DRIVE range can be selected when towing. The
transmission controls include a drive strategy to
avoid frequent shifting when towing. However, if
frequent shifting does occur while in DRIVE, select
TOW/HAUL mode or select a lower gear range (using
the Electronic Range Select (ERS) shift control).

NOTE:Using TOW/HAUL mode or selecting a lower gear
range (using the ERS shift control) while operating
the vehicle under heavy loading conditions will
improve performance and extend transmission life
by reducing excessive shifting and heat build-up.
This action will also provide better engine braking.
6-Speed Automatic Transmission Only
When towing a loaded trailer up steep grades at
low speeds (20 mph [32 km/h] or below), holding
your vehicle in FIRST gear (using the ERS shift
control) can help to avoid transmission
overheating.

If you regularly tow a trailer for more than 45 minutes
of continuous operation, then change the automatic
transmission fluid and filter(s) as specified for "police,
taxi, fleet, or frequent trailer towing."
Ú
page 344.

NOTE:Check the automatic transmission fluid level
before towing (6-speed automatic only).
Tow/Haul Mode
To reduce potential for automatic transmission
overheating, activate TOW/HAUL mode when
driving in hilly areas, or select a lower gear range
(using the Electronic Range Select (ERS) shift
control) on more severe grades.
Cruise Control — If Equipped
Do not use on hilly terrain or with heavy loads.
When using the Cruise Control, if you experience
speed drops greater than 10 mph (16 km/h),
disengage until you can get back to cruising
speed.
Use Cruise Control in flat terrain and with light
loads to maximize fuel efficiency.
SNOWPLOW — IF EQUIPPED
Snowplow Prep Packages are available as a factory
installed option. These packages include
components necessary to equip your vehicle with a
snowplow.
NOTE:Before installation of a snowplow it is highly recom -
mended that the owner/installer obtain and follow
the recommendations contained within the current
Body Builder’s Guide. See an authorized dealer, installer or snowplow manufacturer for this infor
-
mation. There are unique electrical systems that
must be connected to properly ensure operator
safety and prevent overloading vehicle systems.
BEFORE PLOWING
Check the hydraulic system for leaks and proper
fluid level.
Check the mounting bolts and nuts for proper
tightness.
Check the runners and cutting edge for exces -
sive wear. The cutting edge should be ¼ to ½
inches (6 cm to 1.2 cm) above ground in snow
plowing position.
Check that snowplow lighting is connected and
functioning properly.
WARNING!
Attaching a snowplow to this vehicle could
adversely affect performance of the airbag
system in a collision. Do not expect that the
airbag will perform as described earlier in this
manual.
CAUTION!
The “Lamp Out” indicator could illuminate if
exterior lamps are not properly installed.

23_DPF_OM_EN_USC_t.book Page 192

STARTING AND OPERATING193
SNOWPLOW PREP PACKAGE MODEL
A
VAILABILITY
For Information about snowplow applications visit
www.ramtrucks.com or refer to the current Body
Builder’s Guide.

1. The maximum number of occupants in the
truck should not exceed two.

2. The total GVWR or the Front GAWR or the Rear GAWR should never be exceeded.
3. Cargo capacity will be reduced by the addition of options or passengers, etc.
The loaded vehicle weight, including the snowplow
system, all aftermarket accessories, driver,
passengers, options, and cargo, must not exceed
either the Gross Vehicle Weight Rating (GVWR) or
Gross Axle Weight Rating (GAWR). These weights
are specified on the Safety Compliance
Certification Label on the driver's side door
opening.
NOTE:Detach the snowplow when transporting
passengers.
Vehicle front end wheel alignment was set to
specifications at the factory without consideration
for the weight of the plow. Front end toe-in should
be checked and reset if necessary at the beginning
and end of the snowplow season. This will help
prevent uneven tire wear. The blade should be lowered whenever the vehicle
is parked.
Maintain and operate your vehicle and snowplow
equipment following the recommendations
provided by the specific snowplow manufacturer.
OVER THE ROAD OPERATION WITH
S
NOWPLOW ATTACHED
The blade restricts air flow to the radiator and
causes the engine to operate at higher than
normal temperatures. Therefore, when
transporting the plow, angle the blade completely
and position it as low as road or surface conditions
permit. Do not exceed 40 mph (64 km/h). The
operator should always maintain a safe stopping
distance and allow adequate passing clearance.
OPERATING TIPS
Under ideal snow plowing conditions, 20 mph
(32 km/h) should be maximum operating speed.
The operator should be familiar with the area and
surface to be cleaned. Reduce speed and use
extreme caution when plowing unfamiliar areas or
under poor visibility.
GENERAL MAINTENANCE
Snowplows should be maintained in accordance
with the plow manufacturer's instructions.
Keep all snowplow electrical connections and
battery terminals clean and free of corrosion.
When plowing snow, to avoid transmission and
drivetrain damage, the following precautions
should be observed.
Operate with transfer case in 4WD LOW when
plowing small or congested areas where speeds
are not likely to exceed 15 mph (24 km/h). At
higher speeds operate in 4WD HIGH.
Vehicles with automatic transmissions should
use 4WD LOW when plowing deep or heavy
snow for extended periods of time to avoid
transmission overheating.
Do not shift the transmission unless the engine
has returned to idle and wheels have stopped.
Make a practice of stepping on the brake pedal
while shifting the transmission.
4

23_DPF_OM_EN_USC_t.book Page 193