2021 RAM CHASSIS CAB fuel cap

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 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.
8

21_DPF_OM_EN_USC_t.book Page 383

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

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

414SERVICING AND MAINTENANCE
TIRES — GENERAL INFORMATION
Tire Pressure
Proper tire inflation pressure is essential to the
safe and satisfactory operation of your vehicle.
Four primary areas are affected by improper tire
pressure:
Safety
Fuel Economy
Tread Wear
Ride Comfort and Vehicle Stability Safety
Both underinflation and overinflation affect the
stability of the vehicle and can produce a feeling
of sluggish response or over responsiveness in
the steering.
NOTE:
Unequal tire pressures from side to side may
cause erratic and unpredictable steering
response.
Unequal tire pressure from side to side may
cause the vehicle to drift left or right.
Fuel Economy
Underinflated tires will increase tire rolling
resistance resulting in higher fuel consumption.
Tread Wear
Improper cold tire inflation pressures can cause
abnormal wear patterns and reduced tread life,
resulting in the need for earlier tire
replacement.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a
comfortable ride. Overinflation produces a
jarring and uncomfortable ride.
WARNING!

Overloading of your tires is dangerous.
Overloading can cause tire failure, affect
vehicle handling, and increase your stopping
distance. Use tires of the recommended load
capacity for your vehicle. Never overload them.
WARNING!
Improperly inflated tires are dangerous and
can cause collisions.
Underinflation increases tire flexing and
can result in overheating and tire failure.
Overinflation reduces a tire's ability to
cushion shock. Objects on the road and
chuckholes can cause damage that result
in tire failure.
Overinflated or underinflated tires can
affect vehicle handling and can fail
suddenly, resulting in loss of vehicle
control.
Unequal tire pressures can cause steering
problems. You could lose control of your
vehicle.
Unequal tire pressures from one side of the
vehicle to the other can cause the vehicle
to drift to the right or left.
Always drive with each tire inflated to the
recommended cold tire inflation pressure.

21_DPF_OM_EN_USC_t.book Page 414

436TECHNICAL SPECIFICATIONS
FUEL REQUIREMENTS – DIESEL ENGINE
Use good quality diesel fuel from a reputable
supplier in your vehicle. Federal law requires
that you must fuel this vehicle with Ultra Low
Sulfur Highway Diesel fuel (15 ppm Sulfur
maximum) and prohibits the use of Low Sulfur
Highway Diesel fuel (500 ppm Sulfur maximum)
to avoid damage to the emissions control
system.
For most year-round service, Number 2 diesel
fuel meeting ASTM (formerly known as the
American Society for Testing and Materials)
specification D-975 Grade S15 will provide
good performance. If the vehicle is exposed
to extreme cold (below 20°F or -7°C), or is
required to operate at colder-than-normal
conditions for prolonged periods, use climatized
Number 2 diesel fuel or dilute the Number 2
diesel fuel with 50% Number 1 diesel fuel. This
will provide better protection from fuel gelling or
wax-plugging of the fuel filters.
Diesel fuel is seldom completely free of water.
To prevent fuel system trouble, drain the
accumulated water from the fuel/water
separator using the fuel/water separator drain
provided on both fuel filters. If you buy good
quality fuel and follow the cold weather advice
above, fuel conditioners should not be required
in your vehicle. If available in your area, a high
cetane “premium” diesel fuel may offer improved
cold-starting and warm-up performance.

FUEL SPECIFICATIONS
The Cummins® Turbo Diesel engine has been
developed to take advantage of the high energy
content and generally lower cost Number 2
Ultra Low Sulfur diesel fuel or Number 2 Ultra
Low Sulfur climatized diesel fuels. Experience
has shown that it also operates on Number 1
Ultra Low Sulfur diesel fuels or other fuels
within specification.
NOTE:
If you accidentally fill the fuel tank with gaso
-
line on your diesel vehicle, Do not start the
vehicle. If you restart your vehicle you risk
damaging the engine and fuel system. Please
call an authorized 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).
WARNING!
Do not use alcohol or gasoline as a fuel
blending agent. They can be unstable under
certain conditions and hazardous or
explosive when mixed with diesel fuel.
CAUTION!
If the “Water in Fuel Indicator Light” remains
on, DO NOT START engine before you drain
the water from the fuel filter(s) to avoid
engine damage Ú page 375.

21_DPF_OM_EN_USC_t.book Page 436

438TECHNICAL SPECIFICATIONS
Fuel Water Separation — Must Use Mopar/
Cummins Approved Fuel Filter Elements
You must use Mopar/Cummins approved fuel
filter elements in both your engine mounted
filter and frame mounted filter.
Biodiesel fuel has a natural affinity to water and
water accelerates microbial growth. Your
Mopar/Cummins filtration system is designed
to provide adequate fuel water separation
capabilities.
Bio-Diesel Fuel Properties — Low Ambient
Temperatures
Biodiesel fuel may gel or solidify at low ambient
temperatures, which may pose problems for
both storage and operation. Precautions can be
necessary at low ambient temperatures, such
as storing the fuel in a heated building or a
heated storage tank, or using cold temperature
additives.
Fuel In Oil Dilution — Must Adhere To
Required Oil Change Interval

Fuel dilution of lubricating oil has been observed
with the use of biodiesel fuel. Fuel in oil must not
exceed 5%. To ensure this limit is met your oil
change interval must be maintained to the
following schedule:

Ram 3500/4500/5500 Chassis
Cab — 12,500 Miles (20,000 km)*
(*unless otherwise notified with a oil service
message)
CAUTION!

Under no circumstances should oil change
intervals exceed 12,500 miles (20,000 km)
if operation occurs with greater than 5%
biodiesel blends. Oil change intervals should
not exceed six months in either case. Failure
to comply with these Oil Change require -
ments for vehicles operating on biodiesel
blends up to B20 may result in premature
engine wear. Such wear is not covered by the
New Vehicle Limited Warranty.

B20 Biodiesel capable: The engine may
suffer severe damage if operated with
concentrations of Biodiesel higher than
20%.

21_DPF_OM_EN_USC_t.book Page 438

TECHNICAL SPECIFICATIONS439
FLUID CAPACITIES
6.4L GASOLINE ENGINE
6.7L DIESEL ENGINE
US Metric
Fuel (Approximate)
Standard Rear Tank 52 Gallons197 Liters
Optional Midship Tank 22 Gallons83 Liters
Engine Oil With Filter
6.4L Engine 7 Quarts6.6 Liters
Cooling System
6.4L Engine 16.6 Quarts15.7 Liters
USMetric
Fuel (Approximate)
Standard Rear Tank 52 Gallons197 Liters
Optional Midship Tank 22 Gallons83 Liters
Diesel Exhaust Fluid Tank (Approximate) 8.7 Gallons33 Liters
Engine Oil With Filter
6.7L Turbo Diesel Engine 12 Quarts11.4 Liters
9

21_DPF_OM_EN_USC_t.book Page 439