2021 RAM CHASSIS CAB Owners Manual

STARTING AND OPERATING127
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 off
for at least five seconds and then back ON after
the “Wait to Start” telltale 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
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” telltale 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 ON.

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 378.

If the engine stalls, or if the ignition switch is
left ON for more than two minutes after the
“Wait to Start” telltale goes out, reset the
intake air heater by turning the ignition switch
to the OFF position for at least five seconds
and then back ON. Repeat steps 1 through 5 of
“Starting Procedure – Engine Manifold Air
Temperature 0°F to 60°F (-18°C to 19°C).”

4

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128STARTING AND OPERATING
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.
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.
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.

Never leave children alone in a vehicle, or
with access to an unlocked vehicle. Allowing
children 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 mode. A child could
operate power windows, other controls, or
move the vehicle.

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STARTING AND OPERATING129
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”.
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130STARTING AND OPERATING
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.

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 433.
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 temperature present. This may
occur on an unseasonably 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
Úpage 367.
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 Volts 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.

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STARTING AND OPERATING131
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 throttle pedal.
Automatic transmission is in PARK.
Vehicle speed is 0 mph (0 km/h).
Applying the throttle 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 tempera -
ture during extended idle.
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 90.
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132STARTING AND OPERATING
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. Fuel pump noise may
increase during low speed/light load conditions
when ambient temperature is above 100°F
(38°C), and when fuel tank level is below 10%.
This is a normal condition of the fuel system and
controls strategy. If at any time the check
engine light is on, please visit an authorized
dealer.

21_DPF_OM_EN_USC_t.book Page 132

STARTING AND OPERATING133
STOPPING THE ENGINE
Idle the engine a few minutes before routine shutdown. After full load operation, idle the engine three to five minutes before shutting
it down. This idle period will allow the lubricating oil and coolant to carry excess heat away from the combustion chamber, bearings, internal
components, and turbocharger. This is especially important for turbocharged, charge air-cooled engines. Refer to the following chart for proper
engine shutdown:
IDLE SHUTDOWN
This feature can be enabled so that the truck will automatically shutdown when the truck has been idling for a set period of time when the engine is at
operating temperature. Idle time can be set in 5 minute increments between
5 and 60 minutes. See an authorized dealer to enable this feature.
NOTE:
The idle shut down timer is disabled while the PTO (Power Take-off) is active.
Driving Condition Load Turbocharger Temperature Idle Time (min.) Before Engine Shutdown
Stop and Go EmptyCool Less than One
Stop and Go Medium - One
Highway Speeds MediumWarm Two
City Traffic Maximum GCWR - Three
Highway Speeds Maximum GCWR - Four
Uphill Grade Maximum GCWR Hot Five
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134STARTING 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 trans
-
mission 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.

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