2020 RAM CHASSIS CAB Owners Manual

STARTING AND OPERATING271
Adding Diesel Exhaust Fluid (DEF)
The DEF gauge (located on the instrument
cluster) will display the level of DEF remaining in
the tank. Refer to “Instrument Cluster” and
“Instrument Cluster Descriptions” in “Getting To
Know Your Instrument Panel” for further infor -
mation.
NOTE:
Driving conditions (altitude, vehicle speed,
load, etc.) will effect the amount of DEF that
is used in your vehicle.
Another factor is that outside temperature
can affect DEF consumption. In cold condi -
tions, 12°F (-11°C) and below, the DEF
gauge needle can stay on a fixed position and
may not move for extended periods of time.
This is a normal function of the system.
There is an electric heater inside the DEF
tank that automatically works when neces -
sary. And if the DEF supply does freeze, the
truck will operate normally until it thaws.
DEF Fill Procedure
NOTE:
Refer to “Fluids And Lubricants” in “Technical
Specifications” for the correct fluid type.

1. Remove cap from DEF tank (located on
drivers side of the vehicle or in fuel door).

DEF Filler Cap And Fuel Fill Chassis Cab Models

2. Insert DEF fill adapter/nozzle into DEF tank filler neck. NOTE:The DEF gauge may take up to five seconds
to update after adding a gallon or more of
Diesel Exhaust Fluid (DEF) to the DEF tank.
If you have a fault related to the DEF
system, the gauge may not update to the
new level. See an authorized dealer for
service.
The DEF gauge may also not immediately
update after a refill if the temperature of the
DEF fluid is below 39°F (4°C). The DEF line
heater will possibly warm up the DEF fluid
and allow the gauge to update after a period
of run time. Under very cold conditions, it is
possible that the gauge may not reflect the
new fill level for several drives.
Excessive overfilling of the DEF tank can
result in a MIL lamp/fault code and inaccu
-
rate level readings.1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — Diesel Fuel Fill Location
5

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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.
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274STARTING AND OPERATING
TRAILER TOWING
In this section you will find safety tips and infor -
mation 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 recom -
mendations 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.
Refer to “Vehicle Loading/Vehicle Certification
Label” in “Starting And Operating” for further
information.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus the
weight of all cargo, consumables and equip -
ment (permanent or temporary) loaded in or on
the trailer in its "loaded and ready for operation"
condition.
The recommended way to measure GTW is to
put your fully loaded trailer on a vehicle scale.
The entire weight of the trailer must be
supported by the scale.
Gross Combination Weight Rating (GCWR)
The GCWR is the total allowable weight of your
vehicle and trailer when weighed in combina -
tion.
Gross Axle Weight Rating (GAWR)
The GAWR is the maximum capacity of the front
and rear axles. Distribute the load over the front
and rear axles evenly. Make sure that you do
not exceed either front or rear GAWR. Refer to
“Vehicle Loading/Vehicle Certification Label” in
“Starting And Operating” for further informa -
tion.
Tongue Weight (TW)
The tongue weight is the downward force
exerted on the hitch ball by the trailer. You must
consider this as part of the load on your vehicle.
CAUTION!
Do not load your vehicle any heavier than the
GVWR or the 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. Also
overloading can shorten the life of your
vehicle.
WARNING!
If the gross trailer weight is 5,000 lbs
(2,267 kg) or more, it is recommended to use
a weight-distributing hitch to ensure stable
handling of your vehicle. If you use a standard
weight-carrying hitch, you could lose control
of your vehicle and cause a collision.
WARNING!
It is important that you do not exceed the
maximum front or rear GAWR. A dangerous
driving condition can result if either rating is
exceeded. You could lose control of the
vehicle and have a collision.

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STARTING AND OPERATING275
Trailer Frontal Area
The frontal area is the maximum height multi -
plied by the maximum width of the front of a
trailer.
Trailer Sway Control (TSC)
The TSC can be a mechanical telescoping link
that can be installed between the hitch receiver
and the trailer tongue that typically provides
adjustable friction associated with the tele -
scoping motion to dampen any unwanted trailer
swaying motions while traveling.
If equipped, the electronic TSC recognizes a
swaying trailer and automatically applies indi -
vidual wheel brakes and/or reduces engine
power to attempt to eliminate the trailer sway.
Weight-Carrying Hitch
A weight-carrying hitch supports the trailer
tongue weight, just as if it were luggage located
at a hitch ball or some other connecting point of
the vehicle. These kinds of hitches are the most
popular on the market today and they are
commonly used to tow small and medium sized
trailers.
Weight-Distributing Hitch
A weight-distributing system works by applying
leverage through spring (load) bars. They are
typically used for heavier loads to distribute
trailer tongue weight to the tow vehicle's front
axle and the trailer axle(s). When used in accor -
dance with the manufacturer's directions, it
provides for a more level ride, offering more
consistent steering and brake control, thereby
enhancing towing safety. The addition of a fric -
tion/hydraulic sway control also dampens sway
caused by traffic and crosswinds and contrib -
utes positively to tow vehicle and trailer
stability. Trailer Sway Control (TSC) and a weight
distributing (load equalizing) hitch are recom -
mended for heavier Tongue Weights (TW) and
may be required depending on vehicle and
trailer configuration/loading to comply with
GAWR requirements.

Without Weight-Distributing Hitch (Incorrect)
WARNING!
An improperly adjusted weight distributing
hitch system may reduce handling, stability
and braking performance and could result
in a collision.
Weight distributing systems may not be
compatible with surge brake couplers.
Consult with your hitch and trailer manufac-
turer or a reputable Recreational Vehicle
dealer for additional information.
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276STARTING AND OPERATING

With Weight-Distributing Hitch (Correct)
Improper Adjustment Of Weight-Distributing Hitch (Incorrect)
Recommended Distribution Hitch Adjustment

1. Position the truck to be ready to connect to
the trailer (do not connect the trailer).

2. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H1.

Measuring Height (H)
3. Attach the trailer to the vehicle without the
weight distribution bars connected.
4. Measure the height of the top of the front wheel opening on the fender to ground, this
is height H2.
5. Install and adjust the tension in the weight distributing bars per the manufacturers’
recommendations so that the height of the
front fender is approximately
(H2-H1)/2+H1 (about 1/2 the difference
between H2 and H1 above normal ride
height [H1]).

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STARTING AND OPERATING277
6. Perform a visual inspection of the trailer
and weight distributing hitch to confirm
manufacturers’ recommendations have
been met.
NOTE:
For all towing conditions, we recommend towing
with TOW/HAUL mode engaged.Fifth-Wheel Hitch
The fifth-wheel hitch is a special high platform
with a coupling that mounts over the rear axle of
the tow vehicle in the truck bed. It connects a
vehicle and fifth-wheel trailer with a coupling
king pin.
Your truck may be equipped with a fifth wheel
hitch option. Refer to the separately provided
fifth wheel hitch safety, care, assembly, and
operating instructions.
Gooseneck Hitch
The gooseneck hitch employs a pivoted
coupling arm which attaches to a ball mounted
in the bed of a pickup truck. The coupling arm
connects to the hitch mounted over the rear
axle in the truck bed.
Measurement Example Example 2500/
3500 Height (mm)
H1 1,030
H2 1,058
H2-H1 28
(H2-H1)/2 14
(H2-H1)/2 + H1 1,044
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278STARTING AND OPERATING
Trailer Hitch Type and Maximum Trailer Weight
The following chart provides the industry standard for the maximum trailer weight a given trailer hitch class can tow and should be used to assist you
in selecting the correct trailer hitch for your intended towing condition.
Trailer Hitch Classification Definitions
Class Max. Trailer Hitch Industry Standards
Class I - Light Duty 2,000 lbs (907 kg)
Class II - Medium Duty 3,500 lbs (1,587 kg)
Class III - Heavy Duty 5,000 lbs (2,267 kg)
Class IV - Extra Heavy Duty 10,000 lbs (4,535 kg)
Fifth Wheel/Gooseneck Greater than 10,000 lbs (4,535 kg)
Refer to the “Trailer Towing Weights (Maximum Trailer Weight Ratings)” for the Maximum Gross Trailer Weight (GTW) towable for your given drivetrain.
All trailer hitches should be professionally installed on your vehicle.

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