2021 RAM CHASSIS CAB fuel

SERVICING AND MAINTENANCE377
6. Remove the used filter cartridge from the
housing and dispose of according to your
local regulations.
7. Wipe clean the sealing surfaces of the lid and housing.
8. Install new o-ring back into ring groove on the filter housing and lubricate with clean
engine oil.
9. Remove new filter cartridge from plastic bag and install into housing.
NOTE:
Do not remove cartridge from bag until you
reach this step in order to keep cartridge clean.
10. Push down on the cartridge to ensure it is properly seated. Do not pre-fill the filter
housing with fuel.
11. Install lid onto housing and tighten to 22.5 ft lbs (30.5 N.m). Do not overtighten
the lid.
12. Prime the engine Ú page 378. Then start
the engine and confirm there are no leaks.UNDERBODY MOUNTED FUEL FILTER
R
EPLACEMENT
NOTE:
Using a fuel filter that does not meet the
manufacturer's filtration and water sepa -
rating requirements can severely impact fuel
system life and reliability.
The underbody mounted filter housing will
cause the engine not to run if:
a. No filter is installed.

Underbody Mounted Fuel Filter Assembly
1. Ensure engine is turned off.

2. Place drain pan under the fuel filter drain
hose.
3. Open the water drain valve one full turn counterclockwise and completely drain fuel
and water into the approved container.
4. Close the water drain valve.
5. Remove lid using a socket or strap wrench. Rotate counterclockwise for removal.
Remove used o-ring and discard it.
6. Remove the used filter cartridge from the housing and dispose of according to your
local regulations.
1 — Drain Valve
CAUTION!
Diesel fuel will damage blacktop paving
surfaces. Drain the filter into an appro-
priate container.
Do not prefill the fuel filter when installing a
new fuel filter. There is a possibility debris
could be introduced into the fuel filter
during this action. It is best to install the
filter dry and allow the in-tank lift pump to
prime the fuel system.
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21_DPF_OM_EN_USC_t.book Page 377

378SERVICING AND MAINTENANCE
7. Wipe clean the sealing surfaces of the lid
and housing.
8. Install new o-ring back into ring groove on the filter housing and lubricate with clean
engine oil.
NOTE:
Water In Fuel (WIF) sensor is re-usable. Service
kit comes with new o-ring for filter canister and
WIF sensor.
PRIMING IF THE ENGINE HAS RUN OUT
O
F FUEL

1. Add a substantial amount of fuel to the
tank, approximately 2 to 5 gal (8L to 19L).
2. Three priming cycles must be completed.
Turn ignition to the RUN position and wait
approximately 30 seconds. This will activate
the in tank fuel pump. Turn the ignition
switch to the off position, and leave off for at
least 30 seconds. Repeat this procedure
three times before cranking the engine.
3. Start the engine using the “Normal Starting” procedure Ú page 119.
4. Once the engine starts, allow the engine to idle for a minimum of 30 seconds.
NOTE:
The engine may run rough until the air is forced
from all the fuel lines. 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 Cummins diesel engine. (Pickup models
and Chassis Cab models configured with B20
capability.)
WARNING!
Do not open the high pressure fuel system
with the engine running. Engine operation
causes high fuel pressure. High pressure fuel
spray can cause serious injury or death.
CAUTION!
Do not engage the starter motor for more
than 15 seconds at a time. Allow two minutes
between the cranking intervals.
WARNING!
Do not use alcohol or gasoline as a fuel
blending agent. They can be unstable under
certain conditions and be hazardous or
explosive when mixed with diesel fuel.
CAUTION!
Due to lack of lubricants in alcohol or
gasoline, the use of these fuels can cause
damage to the fuel system.

21_DPF_OM_EN_USC_t.book Page 378

SERVICING AND MAINTENANCE379
Use of biodiesel mixture in excess of 20% can
negatively 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 addi -
tives are not necessary for the proper opera -
tion of your Cummins diesel engine.
INTERVENTION REGENERATION
S
TRATEGY — MESSAGE PROCESS FLOW
The Cummins diesel engine meets all
Environmental Protection Agency (EPA) Heavy
Duty Diesel Engine Emissions Standards,
resulting in one of the lowest emitting diesel
engines ever produced.

To achieve these emissions standards, your
vehicle is equipped with a state-of-the-art engine
and exhaust system. The engine and exhaust
after-treatment system work together to achieve
the EPA Heavy Duty Diesel Engine Emissions
Standards. These systems are seamlessly
integrated into your vehicle and managed by the Cummins Powertrain Control Module (PCM).
The PCM manages engine combustion to allow
the exhaust system’s catalyst to trap and burn
Particulate Matter (PM) pollutants, with no input
or interaction on your part.
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.

Additionally, your vehicle has the ability to alert
you to additional maintenance required on your
truck or engine Ú
page 90.
DIESEL EXHAUST FLUID
Diesel Exhaust Fluid (DEF) sometimes known
simply by the name of its active component,
UREA—is a key component of Selective Catalytic
Reduction (SCR) systems, which help diesel
vehicles meet stringent emission regulations.
DEF is a liquid reducing agent that reacts with
engine exhaust in the presence of a catalyst to
convert smog-forming nitrogen oxides (NOx)
into harmless nitrogen and water vapor
Úpage 440.
You can receive assistance in locating DEF in
the United States by calling 866-RAM-INFO
(866-726-4636). In Canada call
1–800–465–2001 (English) or
1–800–387–9983 (French)
WARNING!
A hot exhaust system can start a fire if you
park over materials that can burn. Such
materials might be grass or leaves coming
into contact with your exhaust system. Do not
park or operate your vehicle in areas where
your exhaust system can contact anything
that can burn.
8

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SERVICING AND MAINTENANCE383

Under normal operating conditions, the catalytic
converter will not require maintenance. However,
it is important to keep the engine properly tuned
to ensure proper catalyst operation and prevent
possible catalyst damage.
NOTE:
Intentional tampering with emissions control
systems can result in civil penalties being
assessed against you.

In unusual situations involving grossly
malfunctioning engine operation, a scorching
odor may suggest severe and abnormal catalyst
overheating. If this occurs, stop the vehicle, turn off
the engine and allow it to cool. Service, including a
tune-up to manufacturer's specifications, should be
obtained immediately.

To minimize the possibility of catalytic converter
damage:
Do not interrupt the ignition when the trans
-
mission is in gear and the vehicle is in
motion.
Do not try to start the vehicle by pushing or
towing the vehicle.
Do not idle the engine with any ignition
components disconnected or removed, such
as when diagnostic testing, or for prolonged
periods during very rough idle or malfunc -
tioning operating conditions.
COOLING SYSTEM CAUTION!
The catalytic converter requires the use of
unleaded fuel only. Leaded gasoline will
destroy the effectiveness of the catalyst as
an emissions control device and may seri -
ously reduce engine performance and
cause serious damage to the engine.

Damage to the catalytic converter can result
if your vehicle is not kept in proper operating
condition. In the event of engine malfunc -
tion, particularly involving engine misfire or
other apparent loss of performance, have
your vehicle serviced promptly. Continued
operation of your vehicle with a severe
malfunction could cause the converter to
overheat, resulting in possible damage to
the converter and vehicle.

WARNING!

You or others can be badly burned by hot
engine coolant (antifreeze) or steam from your
radiator. If you see or hear steam coming from
under the hood, do not open the hood until the
radiator has had time to cool. Never open a
cooling system pressure cap when the radiator
or coolant bottle is hot.

Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts automati -
cally and may start at any time, whether the
engine is running or not.
When working near the radiator cooling fan,
disconnect the fan motor lead or turn the
ignition to the OFF mode. The fan is
temperature controlled and can start at any
time the ignition is in the ON mode.
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386SERVICING AND MAINTENANCE
Checking Coolant Level — 6.4L Engine
The level of the coolant in the pressurized
coolant bottle should be between the “MIN” and
“MAX” range on the bottle when the engine is
cold.

The radiator normally remains completely full,
so there is no need to remove the cap unless
checking for coolant freeze point or replacing
engine coolant (antifreeze). Advise your service
attendant of this. As long as the engine operating
temperature is satisfactory, the coolant bottle
need only be checked once a month. When
additional engine coolant is needed to maintain
the proper level, it should be added to the coolant
bottle. Do not overfill.

Cooling System Notes
NOTE:
When the vehicle is stopped after a few miles/
kilometers of operation, you may observe vapor
coming from the front of the engine compart -
ment. This is normally a result of moisture from
rain, snow, or high humidity accumulating on
the radiator and being vaporized when the ther -
mostat opens, allowing hot engine coolant (anti -
freeze) to enter the radiator. If an examination of your engine compartment
shows no evidence of radiator or hose leaks,
the vehicle may be safely driven. The vapor will
soon dissipate.
Do not overfill the coolant expansion bottle.
Check the coolant freeze point in the radiator
and in the coolant expansion bottle. If engine
coolant (antifreeze) needs to be added, the
contents of the coolant expansion bottle
must also be protected against freezing.
If frequent engine coolant additions are
required, the cooling system should be pres
-
sure tested for leaks.
Maintain engine coolant concentration at a
minimum of 50% OAT coolant (conforming to
MS.90032) and distilled water for proper
corrosion protection of your engine which
contains aluminum components.
Make sure that the coolant expansion bottle
overflow hoses are not kinked or obstructed.
Keep the front of the radiator clean. If your
vehicle is equipped with air conditioning,
keep the front of the condenser clean.
Do not change the thermostat for Summer or
Winter operation. If replacement is ever
necessary, install ONLY the correct type ther -
mostat. Other designs may result in unsatis -
factory engine cooling performance, poor gas
mileage, and increased emissions.
CHARGE AIR COOLER — INTER-COOLER

The charge air cooler is positioned below the
radiator and the air conditioner condenser. Air
enters the engine through the air cleaner and
passes through the turbocharger, where it is
pressurized. This pressurized air rapidly reaches
high temperature. The air is then directed
through a hose to the charge air cooler and
through another hose to the intake manifold of
the engine. The air entering the engine has been
cooled by about 50° to 100°F (10° to 38°C).
This cooling process enables more efficient
burning of fuel resulting in fewer emissions.

To guarantee optimum performance of the
system, keep the surfaces of the charge air
cooler, condenser and radiator clean and free
of debris. Periodically check the hoses leading
to and from the charge air cooler for cracks or
loose clamps resulting in loss of pressure and
reduced engine performance.

21_DPF_OM_EN_USC_t.book Page 386

SERVICING AND MAINTENANCE395
Power Distribution Center
The Power Distribution Center is located in the
engine compartment near the battery. This
center contains cartridge fuses, micro fuses,
relays, and circuit breakers. A description of
each fuse and component may be stamped on
the inside cover, otherwise the cavity number of
each fuse is stamped on the inside cover that
corresponds to the following chart.

Power Distribution Center Location

Cavity Cartridge FuseMicro Fuse Description
F01– –Spare
F02 60 Amp Yellow –ABS Pump Motor (HD Only)
F03 60 Amp Yellow –Rad Fan – If Equipped
F04 50 Amp Red 400W Inverter – If Equipped
F05 40 Amp Green –Compressor For Air Suspension – If Equipped
F06 40 Amp Green –Steering Torque Overlay Module (STOM)
F07 40 Amp Green –Starter Solenoid
F08 20 Amp Blue –NOX Sensor – If Equipped
F09 40 Amp Green –Diesel / Fuel Heater – If Equipped
F09 30 Amp Pink –Gas / Brake Vacuum Pump – If Equipped
F10 40 Amp Green –CBC #2 / Ext Lights
F11 40 Amp Green –Brake System Module (ECU and Valves)
8

21_DPF_OM_EN_USC_t.book Page 395

SERVICING AND MAINTENANCE397
F32– –Spare
F33 20 Amp Blue –Trans Control Module – If Equipped
F34 30 Amp Pink –Vehicle System Interface Module #2 – If Equipped
F35 30 Amp Pink –Sunroof – If Equipped
F36 30 Amp Pink –Electric Back Light – If Equipped
F37 30 Amp Pink –Diesel Frame / Fuel Heater #2– If Equipped
F38 30 Amp Pink –Integrated Trailer Brake Module – If Equipped
F39 – –Spare
F40 –10 Amp Red Ventilated Seats – If Equipped
F41 –10 Amp Red Active Grille Shutter / Active Air Dam – If Equipped
F42 –20 Amp Yellow Horn
F43 –15 Amp Blue Heated Steering Wheel – If Equipped
F44 –10 Amp Red Diagnostic Port
F46 –10 Amp Red Upfitters Relay Coil – If Equipped
F47 – –Spare
F48 – –Spare
F49 –10 Amp Red IP Cluster / CSG
F50 –20 Amp Yellow Air Suspension Control Module – If Equipped
F51 –10 Amp RedIgnition Node Module / Keyless Ignition Node Module, Radio Frequency
Hub Module / Electric Steering Column Lock - If Equipped
F52 –5 Amp Tan Battery Sensor
Cavity Cartridge Fuse Micro Fuse Description
8

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398SERVICING AND MAINTENANCE
F53–20 Amp Yellow Trailer Tow – Left Turn/Stop Lights - If Equipped
F54 –20 Amp Yellow Non Memory Adjustable Pedals - If Equipped
F55 – –Spare
F56 –10 Amp Red Fuel Vapor Blocker Valve - If Equipped
F57 –20 Amp Yellow TCM / PCM / Solenoid Trans Pressure SW (RFE Trans Only) – If Equipped
F58 –10 Amp Red Bed Lighting (LED) – If Equipped
F60 – —Spare
F61 –10 Amp Red NH3 Sensor / PM Sensor – If Equipped
F62 –10 Amp Red Air Conditioning Clutch
F63 –20 Amp Yellow Ignition Coils / CAPS
F64 –25 Amp Clear Fuel Injectors / Powertrain Control Module / SRV – If Equipped
F65 –10 Amp Red MOD Inverter (Wake Up) / Power Port / USB IP / WCPM – If Equipped
F66 –10 Amp Red Sunroof / USB Rear– If Equipped
F67 –10 Amp Red UCI Port / USB Front
F68 –10 Amp Red AEB RACAM HTR – If Equipped
F69 –15 Amp Blue SCR Module 12 Volt– If Equipped
F70 –30 Amp Green Fuel Pump Motor / K09 RLY Coil Feed – If Equipped
F71 –25 Amp Clear Amplifier / Active Noise Cancellation – If Equipped
F72 – —Spare
F73 –20 Amp Yellow Fuel Transfer Pump – If Equipped
Cavity Cartridge Fuse Micro Fuse Description

21_DPF_OM_EN_USC_t.book Page 398