2020 Ram 3500 Chassis Cab fuel cap

272STARTING AND OPERATING
(Continued)
3. Stop filling the DEF tank immediately when any of the following happen: DEF stops
flowing from the fill bottle into the DEF tank,
DEF splashes out the filler neck, or a DEF
pump nozzle automatically shuts off.
4. Reinstall cap onto DEF tank. 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 gallons
(7.5 liters) of DEF from portable containers when
your DEF gauge is reading ½ full.

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 over
-
filled and freezes, the system could be
damaged.
When DEF is spilled, clean the area imme -
diately with water and use an absorbent
material 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 gallons (295 liters) will contam -
inate the entire DEF system and will require
replacement. If owners use a container,
funnel or nozzle when refilling the tank, it
should either be new or one that is has only
been used for adding DEF. Mopar provides
an attachable nozzle with its DEF for this
purpose.
CAUTION! (Continued)

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STARTING AND OPERATING273
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 allow -
able 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.
Each axle GAWR is determined by the compo -
nents in the system with the lowest load
carrying capacity (axle, springs, tires or wheels).
Heavier axles or suspension components some -times 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 condi
-
tions, 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 speci -
fied 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.
5

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310IN CASE OF EMERGENCY
F56 –15 Amp Blue Additional Diesel Content - If Equipped (DS 1500 Only)
F56 –10 Amp Red Fuel Vapor Blocker Valve - If Equipped (HD Only)
F57 –20 Amp Yellow TCM/PCM / Solenoid Trans Pressure SW (RFE Trans Only)
– If Equipped (HD Only)
Transmission (DS 1500 Only)
F58 –10 Amp Red Bed Lighting (LED) – If Equipped (HD Only)
F60 –15 Amp Blue Underhood Lamp / TCM – If Equipped (DS 1500 Only)
F61 –10 Amp RedUREA Sensor / PM Sensor – If Equipped (DS 1500 LD
Diesel & Cummins Diesel)
F62 –10 Amp Red Air Conditioning Clutch
F63 –20 Amp Yellow Ignition Coils (Gas), Ignition Coils Capacitors (Gas) / Short
Runner Valve Actuator / Urea Heater Control Unit (DS
1500 LD Diesel) / RLY Coil Feed-SCR (DS 1500 LD Diesel)
F64 –25 Amp ClearFuel Injectors / Powertrain Control Module / SRV – If
Equipped
F65 –10 Amp RedMOD Inverter (Wake Up) / Power Port / USB IP / WCPM –
If Equipped (HD Only)
Spare (DS 1500 Only)
F66 –10 Amp RedSunroof / Light and Rain Sensor Module / Inside Rearview
Mirror / Passenger Window SW / USB Port Rear / Feed for
R/A RLY #2 Coil – If Equipped
F67 –10 Amp RedCD / DVD / UCI Port – If Equipped (HD Only)
Bluetooth Hands-Free Module / CD – If Equipped (DS
1500 Only)
Cavity
Cartridge Fuse Micro Fuse Description

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SERVICING AND MAINTENANCE335
Oil Change Indicator System — Cummins
Diesel
Your vehicle is equipped with an engine oil
change indicator system. This system will alert
you when it is time to change your engine oil by
displaying the words “Oil Change Due” in your
instrument cluster display. The oil change
reminder will remind the owner to change the
engine oil every 15,000 miles (24,000 km) or
500 hours, whichever comes first, except for
the Chassis Cab models configured with
optional B20 capability that are using greater
than 5% levels of biodiesel, which are
12,500 miles (20,000 km) or 400 hours,
whichever comes first. Failure to change the
engine oil per the maintenance schedule can
result in internal engine damage.
An authorized dealer will reset the oil change
indicator message after completing the sched -
uled oil change. If a scheduled oil change is
performed by someone other than an autho -
rized dealer, the message can be reset by refer -
ring to the steps described under “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel” for further information. Replace the engine oil and oil filter every 15,
000 miles (24,000 km) or 12 months, or
sooner if prompted by the oil change indicator
system. Under no circumstances should oil
change intervals exceed 15,000 miles (24,
000 km) or 12 months, whichever comes first.
NOTE:
Under no circumstances should oil change
intervals exceed 15,000 miles (24,000 km)
or 12 months or 500 Hours, whichever
comes first.
Replace the engine oil and oil filter every
12,500 miles (20,000 km) or 400 hours,
whichever comes first when running greater
than 5% levels of biodiesel (Chassis Cab
models configured with optional B20 capa
-
bility).
If Chassis Cab models configured with optional
B20 capability are operated with greater than
5% levels of biodiesel, the oil change interval
must not exceed 12,500 miles (20,000 km) or
400 hours, whichever comes first under any
circumstances. See the Fuel Requirements
section for more information regarding opera -
tion with biodiesel blend (B6-B20) fuel meeting
ASTM specification D-7467.
Perform Service Indicator — Cummins
Diesel
Your vehicle will require emissions mainte -
nance at a set interval. To help remind you
when this maintenance is due, the instrument
cluster will display “Perform Service”. When the
“Perform Service” message is displayed on the
instrument cluster it is necessary to have the
emissions maintenance performed. Emissions
maintenance may include replacing the Closed
Crankcase Ventilation (CCV) filter element. The
procedure for clearing and resetting the
“Perform Service” indicator message is located
in the appropriate Service Information.
7

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SERVICING AND MAINTENANCE345
Checking Oil Level — Gas Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. Check the oil level at regular
intervals, such as every fuel stop. The best time
to check the engine oil level is about five
minutes after a fully warmed up engine is shut
off.
Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
readings. Always maintain the oil level within
the SAFE zone on the dipstick. Adding one quart
of oil when the reading is at the bottom of the
SAFE zone will result in a reading at the top of
the safe zone on these engines.
Checking Oil Level — Diesel Engine
To ensure proper lubrication of your vehicle's
engine, the engine oil must be maintained at
the correct level. Check the oil level at regular
intervals. The best time to check the oil level is
before starting the engine after it has been parked overnight. When checking oil after oper
-
ating the engine, first ensure the engine is at full
operating temperature, then wait for
30 minutes after engine shutdown to check the
oil.

Engine Oil Dipstick

Checking the oil while the vehicle is on level
ground will improve the accuracy of the oil level
readings. Add oil only when the level on the
dipstick is below the “ADD” mark. The total
capacity from the ADD mark to the Full mark is
2 Quarts (1.9Liters). Never operate the engine with oil level below
the “ADD” mark or above the upper “SAFE”
mark.
Adding Washer Fluid
The fluid reservoir is located under the hood
and should be checked for fluid level at regular
intervals. Fill the reservoir with windshield
washer solvent only (not radiator antifreeze).
When refilling the washer fluid reservoir, take
some washer fluid and apply it to a cloth or
towel and wipe the wiper blades clean. This will
help blade performance.
To prevent freeze-up of your windshield washer
system in cold weather, select a solution or
mixture that meets or exceeds the temperature
range of your climate. This rating information
can be found on most washer fluid containers.
CAUTION!
Overfilling or underfilling will cause oil
aeration or loss of oil pressure. This could
damage your engine.
1 — ADD Range
2 — Full Mark
3 — SAFE Range
CAUTION!
Overfilling or underfilling the crankcase will
cause oil aeration or loss of oil pressure. This
could damage your engine.
7

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358SERVICING AND MAINTENANCE
Priming If The Engine Has Run Out Of 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. Refer to “Starting Procedures”
in “Starting and Operating” for further infor -
mation.
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.)
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.
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.

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366SERVICING 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 oper -
ating temperature is satisfactory, the coolant
bottle need only be checked once a month.
When additional engine coolant (antifreeze) is
needed to maintain the proper level, it should
be added to the coolant bottle. Do not overfill.
Points To Remember
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 (antifreeze) addi-
tions are required, the cooling system should
be pressure tested for leaks.
Maintain engine coolant (antifreeze) concen
-
tration at a minimum of 50% OAT coolant
(conforming to MS.90032) and distilled
water for proper corrosion protection of your
engine which contains aluminum compo -
nents.
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 coolant (antifreeze)
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 mani -
fold 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.

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382SERVICING 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 replace -
ment.
Ride Comfort And Vehicle Stability
Proper tire inflation contributes to a comfort -
able 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.

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