2023 RAM CHASSIS CAB fuel pressure

122STARTING AND OPERATING
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the engine is
operating.
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine oil pressure is above 10 psi (69 kPa) at
idle.
Voltmeter operation: The voltmeter may show a gauge fluctuation at
various engine temperatures. This cycling
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. Post-heat
operation can run for several minutes, and then
the electrical system and voltmeter needle will
stabilize.
The cycling action will cause temporary dimming of
the headlamps, interior lamps, and also a
noticeable reduction in blower motor speed.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
Fuel Operating Range
NOTE:Use Ultra Low Sulfur Diesel (ULSD) Fuels
ONLY.
Fuel Operating Range Chart

*Number 1 ULSD Fuel should only be used where
extended arctic conditions (0°F/-18°C) exist.
NOTE:
Use of Climatized ULSD or Number 1 ULSD Fuel
results in a noticeable decrease in fuel
economy.
Climatized ULSD Fuel is a blend of Number 2
ULSD and Number 1 ULSD Fuels which reduces
the temperature at which wax crystals form in
fuel.
Never leave children alone in a vehicle, or with
access to an unlocked vehicle. Allowing chil -
dren to be in a vehicle unattended is
dangerous for a number of reasons. A child or
others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the gear
selector. Do not leave the key fob in or near
the vehicle (or in a location accessible to chil -
dren), and do not leave the ignition of a
vehicle equipped with Keyless Enter ‘n Go™ in
the ACC or ON/RUN position. A child could
operate power windows, other controls, or
move the vehicle.
WARNING!

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STARTING AND OPERATING123
The fuel grade should be clearly marked on the
pump at the fuel station.
The engine requires the use of ULSD Fuel. Use
of incorrect fuel could result in engine and
exhaust system damage Ú page 413.
If climatized or diesel Number 1 ULSD Fuel is
not available, and you are operating below
(20°F/-6°C), in sustained arctic conditions,
Mopar® Premium Diesel Fuel Treatment (or
equivalent) is recommended to avoid gelling
(see Fuel Operating Range Chart).
Under some circumstances increased engine
noise may be audible in the seconds following a
cold start. This is most likely to occur when using
fuel that isn't blended for the ambient tempera -
ture present. This may occur on an unseason -
ably cold day or when a truck is fueled in a
warmer climate and driven to a colder climate.
The noise can typically be prevented by using
Mopar® Premium Diesel Fuel Treatment as
recommended (see Fuel Operating Range
Chart).
Engine Oil Usage
For the correct engine oil viscosity Ú page 353.
Winter Front Cover Usage
A Winter front or cold weather cover is to be used
in ambient temperatures below 32°F (0°C),
especially during extended idle conditions. This
cover is equipped with four flaps for managing total grille opening in varying ambient
temperatures. If a Winter front or cold weather
cover is to be used the flaps should be left in the
full open position to allow air flow to the charge air
cooler and automatic transmission oil cooler.
When ambient temperatures drop below 0°F
(-17°C) the four flaps need to be closed. A suitable
cold weather cover is available from a Mopar®
dealer.
Battery Blanket Usage
A battery loses 60% of its cranking power as the
battery temperature decreases to 0°F (-18°C). For
the same decrease in temperature, the engine
requires twice as much power to crank at the same
RPM. The use of 120 Volt AC powered battery
blankets will greatly increase starting capability at
low temperatures. Suitable battery blankets are
available from an authorized Mopar® dealer.
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 1,000 RPM during the warm-up period,
especially in cold ambient temperature conditions.
Your vehicle is equipped with an engine warm-up
protection feature that may limit engine
performance after cold starting at low ambient
temperatures. The length of time engine speed is
limited is dependent upon engine coolant
temperature. Engine speed may be briefly limited
to 1,000 RPM after starting with coolant
temperature below freezing conditions, and may
be limited to 1,000 RPM for up to approximately
two minutes under more severe cold conditions.
NOTE:If ambient temperatures are low and the coolant
temperature is below 180°F (82°C), the engine
idle speed will slowly increase to 1,000 RPM after
two minutes of idle, if the following conditions are
met:
Foot is off brake pedal and accelerator pedal.
Automatic transmission is in PARK.
Vehicle speed is 0 mph (0 km/h).
Applying the accelerator pedal will cancel fast
idle.
Operating the exhaust brake at idle will greatly
improve warm-up rate and will help keep the
engine close to operating temperature during
extended idle.
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124STARTING AND OPERATING
ENGINE IDLING

Avoid prolonged idling. Long periods of idling may be
harmful to your engine because combustion
chamber temperatures can drop so low that the fuel
may not burn completely. Incomplete combustion
allows carbon and varnish to form on piston rings,
engine valves, and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting the
oil and causing rapid wear to the engine.

If the engine is allowed to idle or the truck is driven
on low engine speed drive cycles for more than two
hours, the system will automatically enter an
emissions operating mode that will increase the
engine idle speed to 900 RPM (1,050 RPM for
Chassis Cab). While in this mode, which is
designed to help maintain the Diesel Particulate
Filter, the engine idle speed will return to normal
when the brake pedal is applied. A small change in
engine tone or a slight change in engine
performance while accelerating may also be
noticeable at speeds below 20 mph (32 km/h).
This operating mode may last for up to an hour of
idle time, or around 20 minutes of driving time.

Your truck may have been ordered with an optional
voltage monitoring idle up feature. If a load is placed
on the electrical system while the truck is in PARK,
this feature will attempt to maintain normal system
voltage by automatically increasing engine idle
speed. You may notice several consecutive increases
in idle speed, up to a maximum of 1,450 RPM, as the system will attempt to utilize the smallest increase in
idle speed necessary to maintain normal system
voltage. The idle speed will return to normal when
either the electrical load is removed, or when the
brake pedal is applied.

NOTE:For instrument cluster display messages related to
the vehicle's exhaust system Ú
page 89.
Idle-Up Feature
The driver-controlled high idle speed feature will
help increase cylinder temperatures and provide
additional cab heat, however, excessive idling may
still cause the exhaust after-treatment system to
not properly regenerate. Extended periods of idle
time should be avoided.
The Idle-Up feature uses the Cruise Control buttons
to increase engine idle speed and quickly warm the
vehicle's interior.

1. With the transmission in PARK, the parking
brake applied, and the engine running, turn
on the Cruise Control, then push the SET (-)
button.

2. The engine RPM will go up to 1,100 RPM. To increase the RPM, push and hold the RES (+)
button and the idle speed will increase to
approximately 1,500 RPM. To decrease the
RPM, push and hold the SET (-) button and the
idle speed will decrease to approximately
1,100 RPM. 3. To cancel the Idle–Up feature, either push the
CANCEL button, push the ON/OFF button, or
press the brake pedal.
NOISE
Diesel engines can create noises that may seem
as a concern. The nature of a diesel engine is
compression ignition where compressed air and
fuel are mixed and ignited. Weather, barometric
pressure, altitude and temperature will affect how
fuel is ignited in the engine. Engines will sound
different from day to day or previous model years.
Clicking, ticking, or light knocking is normal and will
change from day to day, as the engine breaks in,
and can vary with changes in ambient
temperature; this is normal. Diesel equipped
vehicles also have an exhaust after treatment
system to reduce emissions utilizing a Diesel
Particulate Filter (DPF) and a Selective Reduction
Catalyst (SCR). The SCR reduces Nox using the
Diesel Exhaust Fluid (DEF) system. DEF is injected
directly into the SCR through an dosing module.
This process will create a clicking sound and at
times, will make noise even with the vehicle shut
off. This is normal as the DEF dosing module is
purging DEF. If at any time the check engine light is
on, please visit an authorized dealer.

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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.

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128STARTING AND OPERATING
ENGINE BREAK-IN RECOMMENDATIONS —
DIESEL ENGINE
The Cummins® Turbo Diesel engine does not
require a break-in period due to its construction.
Normal operation is allowed, providing the
following recommendations are followed:
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
indicators.
Check the coolant and oil levels frequently.
Vary throttle position at highway speeds when
carrying or towing significant weight.
NOTE:Light duty operation such as light trailer towing or
no load operation will extend the time before the
engine is at full efficiency. Reduced fuel economy
and power may be seen at this time.
For additional vehicle break-in requirements
Úpage 186. Because of the construction of the Cummins®
Turbo 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).
PARKING BRAKE
Before leaving the vehicle, make sure that the
parking brake is fully applied. Also, be certain to
leave the transmission in PARK.
The foot operated parking brake is located below
the lower left corner of the instrument panel. To
apply the parking brake, firmly push the parking
brake pedal fully. To release the parking brake, pull
the parking brake release handle.

Parking Brake Release
When the parking brake is applied with the ignition
switch ON, the Brake Warning Light in the
instrument cluster will illuminate.
NOTE:
When the parking brake is applied and the
transmission is placed in gear, the Brake
Warning Light will flash. If vehicle speed is
detected, a chime will sound to alert the driver.
Fully release the parking brake before
attempting to move the vehicle.
This light only shows that the parking brake is
applied. It does not show the degree of brake
application.
When parking on a hill, it is important to turn the
front wheels toward the curb on a downhill grade
and away from the curb on an uphill grade. Apply
the parking brake before placing the gear selector
in PARK, otherwise the load on the transmission
locking mechanism may make it difficult to move
the gear selector out of PARK. The parking brake
should always be applied whenever the driver is
not in the vehicle.

23_DPF_OM_EN_USC_t.book Page 128

STARTING AND OPERATING181
Each axle GAWR is determined by the components
in the system with the lowest load carrying capacity
(axle, springs, tires or wheels). Heavier axles or
suspension components sometimes specified by
purchasers for increased durability does not
necessarily increase the vehicle's GVWR.
TIRE SIZE
The tire size on the Vehicle Certification Label
represents the actual tire size on your vehicle.
Replacement tires must be equal to the load
capacity of this tire size.
RIM SIZE
This is the rim size that is appropriate for the tire
size listed.
INFLATION PRESSURE
This is the cold tire inflation pressure for your
vehicle for all loading conditions up to full GAWR.
CURB WEIGHT
The curb weight of a vehicle is defined as the total
weight of the vehicle with all fluids, including
vehicle fuel, at full capacity conditions, and with no
occupants or cargo loaded into the vehicle. The
front and rear curb weight values are determined
by weighing your vehicle on a commercial scale
before any occupants or cargo are added.
LOADING
The actual total weight and the weight of the front
and rear of your vehicle at the ground can best be
determined by weighing it when it is loaded and
ready for operation.

The entire vehicle should first be weighed on a
commercial scale to ensure that the GVWR has not
been exceeded. The weight on the front and rear of the
vehicle should then be determined separately to be
sure that the load is properly distributed over the front
and rear axles. Weighing the vehicle may show that the
GAWR of either the front or rear axle has been
exceeded but the total load is within the specified
GVWR. If so, weight must be shifted from front to rear
or rear to front as appropriate until the specified weight
limitations are met. Store the heavier items down low
and be sure that the weight is distributed equally. Stow
all loose items securely before driving.

Improper weight distributions can have an adverse
effect on the way your vehicle steers and handles
and the way the brakes operate.
TRAILER TOWING
In this section you will find safety tips and
information on limits to the type of towing you can
reasonably do with your vehicle. Before towing a
trailer, carefully review this information to tow your
load as efficiently and safely as possible.
To maintain the New Vehicle Limited Warranty
coverage, follow the requirements and
recommendations in this manual concerning
vehicles used for trailer towing.
COMMON TOWING DEFINITIONS
The following trailer towing related definitions will
assist you in understanding the following
information:
Gross Vehicle Weight Rating (GVWR)
The GVWR is the total allowable weight of your
vehicle. This includes driver, passengers, cargo
and tongue weight. The total load must be limited
so that you do not exceed the GVWR Ú page 180.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the weight
of all cargo, consumables and equipment
(permanent or temporary) loaded in or on the
trailer in its "loaded and ready for operation"
condition.WARNING!
Do not load your vehicle any heavier than the
GVWR, maximum Payload or maximum front and
rear GAWR. If you do, parts on your vehicle can
break, or it can change the way your vehicle
handles. This could cause you to lose control.
Overloading can shorten the life of your vehicle.
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MULTIMEDIA201
Display
When the Display button is pressed on the touchscreen, the system will display the options related to the theme (if equipped), brightness, and color of the
touchscreen. The available settings are:
NOTE:Depending on the vehicle’s options, feature settings may vary.
Setting Name Description
Language This setting will change the language of the Uconnect system and Instrument
Cluster Display. The available languages are English, Français, Italiano, and
Español.
Display Mode This setting will allow you to set the brightness manually or have the system
set it automatically. The “Auto” setting has the system automatically adjust
the display brightness. The “Manual” setting will allow the user to adjust the
brightness of the display.
Display Brightness With Headlights ON/Brightness This setting will allow you to set the brightness when the headlights are on. To
access this setting, Display Mode must be set to Manual. The “+” setting will
increase the brightness; the “-” will decrease the brightness.
Display Brightness With Headlights OFF/Brightness This setting will allow you to set the brightness when the headlights are off. To
access this setting, Display Mode must be set to Manual. The “+” setting will
increase the brightness; the “-” will decrease the brightness.
Set Theme This setting will allow you to change the display theme.
Units The available settings are “Speed” (MPH or km/h), “Distance” (mi or km),
“Fuel Consumption” (MPG [US], MPG [UK], L/100 km, or km/L), “Pressure”
(psi, kPa, or bar), “Temperature” (°C or °F), “Power” (HP [US], Gal HP [UK], or
kW), and “Torque” (lb-ft or Nm) units of measurement independently.
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MULTIMEDIA203
Display Mode This setting will adjust the display for the radio to “Auto” or “Manual”.
“Manual” allows for more customization with the radio display.
Display Brightness Headlights On This setting will allow you to set the brightness when the headlights are on. To
access this setting, Display Mode must be set to “Manual”. The “+” setting will
increase the brightness; the “-” will decrease the brightness.
Display Brightness Headlights Off This setting will allow you to set the brightness when the headlights are off. To
access this setting, Display Mode must be set to “Manual”. The “+” setting will
increase the brightness; the “-” will decrease the brightness.
Set Theme This setting will allow you to change the display theme.
Units The available settings are “Speed” (MPH or km/h), “Distance” (mi or km),
“Fuel Consumption” (MPG [US], MPG [UK], L/100 km, or km/L), “Pressure”
(psi, kPa, or bar), “Temperature” (°C or °F), “Power” (HP [US], Gal HP [UK], or
kW), and “Torque” (lb-ft or Nm) units of measurement independently.
Theme Mode This setting will allow you to adjust the brightness of your theme. Setting
options are “Light”, “Dark” and “Auto”. Select to show themes in Light or Dark
mode. “Auto” changes the theme with the headlights.
Touchscreen Beep This setting will allow you to turn the touchscreen beep on or off.
Show Main Category Bar Labels This setting will allow the main category bar labels to be shown on or off.
Navigation Turn-by-Turn Displayed in Cluster This setting will display navigation prompts in the Instrument Cluster Display.
Phone Pop-ups Displayed In Cluster This setting will display incoming calls in the Instrument Cluster Display.
Time Format This setting will allow you to set the time format (AM/PM). Sync Time With GPS
must be “Off” for this setting to be available. The “12 hrs” setting will set the
time to a 12-hour format. The “24 hrs” setting will set the time to a 24-hour
format.
Setting Name
Description
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