engine RAM CHASSIS CAB 2021 Owners Manual

166STARTING AND OPERATING
(Continued)
The following conditions will also deactivate the
Cruise Control without erasing the set speed
from memory:
Vehicle parking brake is applied
Stability event occurs
Gear selector is moved out of DRIVE
Engine overspeed occurs
Pushing the on/off button, or placing the
ignition in the OFF position, erases the set
speed from memory.
ADAPTIVE CRUISE CONTROL (ACC) — IF
E
QUIPPED

Adaptive Cruise Control (ACC) increases the
driving convenience provided by Cruise Control
while traveling on highways and major roadways.
However, it is not a safety system and not
designed to prevent collisions. The Cruise Control
function performs differently if your vehicle is not
equipped with ACC
Ú
page 164.
ACC will allow you to keep Cruise Control
engaged in light to moderate traffic conditions
without the constant need to reset your speed.
ACC utilizes a radar sensor and a forward facing
camera designed to detect a vehicle directly
ahead of you to maintain a set speed.
NOTE:
If the ACC sensor detects a vehicle ahead,
ACC will apply limited braking or acceleration
(not to exceed the original set speed) auto
-
matically to maintain a preset following
distance, while matching the speed of the
vehicle ahead.
Any chassis/suspension or tire size modifica -
tions to the vehicle will affect the perfor -
mance of the Adaptive Cruise Control and
Forward Collision Warning system.
Fixed Speed Cruise Control alone (an ACC
distance not set) will not detect vehicles
directly ahead of you. Always be aware of the
mode selected.
WARNING!

Adaptive Cruise Control (ACC) is a conve -
nience system. It is not a substitute for active
driver involvement. It is always the driver’s
responsibility to be attentive of road, traffic,
and weather conditions, vehicle speed,
distance to the vehicle ahead; and, most
importantly, brake operation to ensure safe
operation of the vehicle under all road condi -
tions. Your complete attention is always
required while driving to maintain safe
control of your vehicle. Failure to follow these
warnings can result in a collision and death
or serious personal injury.

The ACC system:
Does not react to pedestrians,
oncoming vehicles, and stationary
objects (e.g., a stopped vehicle in a
traffic jam or a disabled vehicle).
Cannot take street, traffic, and weather
conditions into account, and may be
limited upon adverse sight distance
conditions.

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STARTING AND OPERATING171
To Vary The Speed Setting
To Increase Or Decrease The Set Speed
After setting a speed, you can increase the
set speed by pushing the RES (+) button, or
decrease speed by pushing the SET (-) button.
U.S. Speed (mph)
Pushing the RES (+) button, or SET (-) button
once will result in a 1 mph speed adjustment.
Each subsequent tap of the button results in
an adjustment of 1 mph.
If the button is continually pushed, the set
speed will continue to adjust in 5 mph incre -
ments until the button is released. The new
set speed is reflected in the instrument
cluster display.
Metric Speed (km/h)
Pushing the RES (+) button, or SET (-) button
once will result in a 1 km/h speed adjust -
ment. Each subsequent tap of the button
results in an adjustment of 1 km/h.
If the button is continually pushed, the set
speed will continue to adjust in 10 km/h
increments until the button is released.
The new set speed is reflected in the instru -
ment cluster display. When An ACC Distance Is Also Set: 
When you use the SET (-) button to decel -
erate, if the engine’s braking power does not
slow the vehicle sufficiently to reach the set
speed, the brake system will automatically
slow the vehicle.
 The ACC system applies the brake down to a
full stop when following the vehicle in front.
If your vehicle follows the vehicle in front to
a standstill, your vehicle will release the
brakes two seconds after coming to a
complete stop.
 The ACC system maintains set speed when
driving uphill and downhill. However, a slight
speed change on moderate hills is normal.
In addition, downshifting may occur while
climbing uphill or descending downhill. This
is normal operation and necessary to main-
tain set speed. When driving uphill and
down -hill, the ACC system will cancel if the
braking temperature exceeds normal range
(over -heated).
Setting The Following Distance In ACC

The specified following distance for Adaptive
Cruise Control (ACC) can be set by varying the
distance setting between four bars (longest),
three bars (long), two bars (medium) and one
bar (short). Using this distance setting and the
vehicle speed, ACC calculates and sets the
distance to the vehicle ahead. This distance
setting displays in the instrument cluster display.
Distance Settings

1 — Longest Distance Setting (Four Bars)
2 — Long Distance Setting (Three Bars)
3 — Medium Distance Setting (Two Bars)
4 — Short Distance Setting (One Bar)
4

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STARTING AND OPERATING195
ENGINE RUNAWAY
Diesel engine runaway is a rare condition
affecting diesel engines, where the engine
consumes its own lubrication oil and runs at
higher and higher RPM until it overspeeds to
a point where it destroys itself due to either
mechanical failure or engine seizure through
lack of lubrication.
REFUELING THE VEHICLE — GASOLINE
ENGINE
NOTE:
When the fuel nozzle “clicks” or shuts off the
fuel tank is full. NOTE:
Tighten the gas cap a quarter turn until you hear
one click. This is an indication that the cap is
properly tightened.
If the gas cap is not tightened properly, the
Malfunction Indicator Light will come on.
Be sure the gas cap is tightened every time the
vehicle is refueled.
WARNING!
In case of engine runaway due to flammable
fumes from fuel spills or turbocharger oil
leaks being sucked into the engine, do the
following to help avoid personal injury and/or
vehicle damage:
Turn the ignition switch to the OFF position.

Using a CO2 or dry chemical type fire extin
-
guisher, direct the spray from the fire extin -
guisher into the grille on the passenger side so
that the spray enters the engine air intake.

The inlet for the engine air intake is located
behind the passenger side headlamp and
receives air through the grille.
CAUTION!
Damage to the fuel system or emissions
control system could result from using an
improper fuel tank filler tube cap (fuel filler
cap). A poorly fitting cap could let impurities
into the fuel system. Also, a poorly-fitted
aftermarket cap can cause the MIL
(Malfunction Indicator Light) to illuminate
due to fuel vapors escaping from the
system.
A poorly fitting fuel filler cap may cause the
MIL to turn on.
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling.
WARNING!
Never have any smoking materials lit in
or near the vehicle when the gas cap is
removed or the tank is being filled.
Never add fuel to the vehicle when the
engine is running. This is in violation of
most state and federal fire regulations and
may cause the MIL to turn on.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle.
You could be burned. Always place gas
containers on the ground while filling.
4

21_DPF_OM_EN_USC_t.book Page 195

196STARTING AND OPERATING
LOOSE FUEL FILLER CAP MESSAGE
If the vehicle diagnostic system
determines that the fuel filler cap
is loose, improperly installed, or
damaged, a loose gASCAP indicator
will display in the instrument cluster telltale
display area Ú page 90. Tighten the fuel filler
cap properly and push the RIGHT button to turn
off the message. If the problem continues, the
message will appear the next time the vehicle is
started.
REFUELING THE VEHICLE — DIESEL ENGINE
NOTE:
When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
Tighten the fuel filler cap until you hear a
“clicking” sound. This is an indication that the
fuel filler cap is properly tightened.
Make sure that the fuel filler cap is tightened
each time the vehicle is refueled.
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective
Catalytic Reduction (SCR) system to meet the
very stringent diesel emissions standards
required by the Environmental Protection
Agency.

The purpose of the SCR system is to reduce levels
of NOx (oxides of nitrogen emitted from engines)
that are harmful to our health and the
environment to a near-zero level. A small quantity
of Diesel Exhaust Fluid (DEF) is injected into the
exhaust upstream of a catalyst where, when
vaporized, it converts smog-forming nitrogen
oxides (NOx) into harmless nitrogen (N2) and
water vapor (H2O), two natural components of
the air we breathe. You can operate with the
comfort that your vehicle is contributing to a
cleaner, healthier world environment for this and
generations to come.

System Overview
This vehicle is equipped with a Diesel Exhaust
Fluid (DEF) injection system and a Selective
Catalytic Reduction (SCR) catalyst to meet the
emission requirements.
The DEF injection system consists of the
following components:
DEF tank
DEF pump
DEF injector
Electronically-heated DEF lines
DEF control module
NOx sensors
Temperature sensors
SCR catalyst
UQS Sensor
For system messages and warnings Úpage 90.
CAUTION!
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle.
You could be burned. Always place gas
containers on the ground while filling.

21_DPF_OM_EN_USC_t.book Page 196

STARTING AND OPERATING197
NOTE:

Your vehicle is equipped with a DEF injection
system. You may occasionally hear an audible
clicking noise. This is normal operation.

The DEF pump will run for a period of time
after engine shutdown to purge the DEF
system. This is normal operation.
Diesel Exhaust Fluid Storage

Diesel Exhaust Fluid (DEF) is considered a very
stable product with a long shelf life. If DEF is kept
in temperatures between 10° and 90°F (-12°
and 32°C), it will last a minimum of one year.

DEF is subject to freezing at the lowest
temperatures. For example, DEF may freeze
at temperatures at or below 12°F (-11°C).
The system has been designed to operate in
this environment.
NOTE:

When working with DEF, it is important to know that:

Any containers or parts that come into contact
with DEF must be DEF compatible (plastic or
stainless steel). Copper, brass, aluminum, iron or non-stainless steel should be avoided as
they are subject to corrosion by DEF.

If DEF is spilled, it should be wiped up
completely.
Adding Diesel Exhaust Fluid (DEF)
The DEF gauge (located on the instrument
cluster) will display the level of DEF remaining in
the tank Ú
page 90.
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:
For the correct fluid type Ú
page 440.
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

1 — Diesel Exhaust Fluid (DEF) Fill Location
2 — Diesel Fuel Fill Location
4

21_DPF_OM_EN_USC_t.book Page 197

198STARTING AND OPERATING
(Continued)
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 tank
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.
At 40°F (4°C) you could see some increase
in the DEF gauge due to the tank thawing.
The gauge and level sensor are working prop-
erly and is just updating with proper thawed
DEF.
Excessive overfilling of the DEF tank can
result in a MIL lamp/fault code and inaccu -
rate level readings. Refilling With Nozzles
You can fill up at any DEF distributor.
Proceed as follows:
Insert the DEF nozzle in the filler, start
refilling and stop refilling at the first shut-off
(the shut-off indicates that the DEF tank is
full). DO NOT proceed with the refilling, to
prevent spillage of DEF.
Extract the nozzle.
Refilling With Containers
Proceed as follows:
Check the expiration date.
Read the advice for use on the label before
pouring the content of the bottle into the DEF
tank.
After the indication appears on the instru -
ment panel display Ú page 90 fill the DEF
tank with no more than 6 Gallons (22 liters).
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.

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STARTING AND OPERATING201
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
Úpage 199.
Gross Trailer Weight (GTW)
The GTW is the weight of the trailer plus
the weight of all cargo, consumables and
equipment (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 combination.

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
Ú
page 199.

Tongue Weight (TW)
The TW is the downward force exerted on the
hitch ball by the trailer. You must consider this
as part of the load on your vehicle.
Trailer Frontal Area
The frontal area is the maximum height
multiplied 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 telescoping motion to
dampen any unwanted trailer swaying motions
while traveling.

If equipped, the electronic TSC recognizes a
swaying trailer and automatically applies
individual 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 commonly used to tow
small and medium sized trailers.

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.
4

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STARTING AND OPERATING205
TRAILER TOWING WEIGHTS (MAXIMUM
T
RAILER WEIGHT RATINGS)
NOTE:
For trailer towing information (maximum trailer
weight ratings) refer to the following website
addresses:
ramtrucks.com/en/towing_guide/
ramtruck.ca (Canada)
rambodybuilder.com
TRAILER AND TONGUE WEIGHT
Never exceed the maximum tongue weight
stamped on your bumper or trailer hitch.

Weight Distribution
Consider the following items when computing
the weight on the rear axle of the vehicle:The tongue weight of the trailer.
The weight of any other type of cargo or
equipment put in or on your vehicle.
The weight of the driver and all passengers.
NOTE:

Remember that everything put into or on the
trailer adds to the load on your vehicle. Also, addi -
tional factory-installed options or dealer-installed
options must be considered as part of the total
load on your vehicle. For the maximum combined
weight of occupants and cargo for your vehicle

Ú
page 411.

TOWING REQUIREMENTS
To promote proper break-in of your new vehicle
drivetrain components, the following guidelines
are recommended.
Perform the maintenance listed in the
“Scheduled Servicing” Ú page 353. When
towing a trailer, never exceed the GAWR or
GCWR ratings.
CAUTION!
Always load a trailer with 60% of the weight in
the front of the trailer. This places 10% of the
GTW on the tow hitch of your vehicle. Loads
balanced over the wheels or heavier in the
rear can cause the trailer to sway severely
side to side which will cause loss of control of
the vehicle and trailer. Failure to load trailers
heavier in front is the cause of many trailer
collisions.
CAUTION!
Do not tow a trailer at all during the first
500 miles (805 km) the new vehicle is driven. The engine, axle or other parts could
be damaged.
Then, during the first 500 miles (805 km)
that a trailer is towed, do not drive over
50 mph (80 km/h) and do not make starts
at full throttle. This helps the engine and
other parts of the vehicle wear in at the
heavier loads.
4

21_DPF_OM_EN_USC_t.book Page 205

206STARTING AND OPERATING
(Continued)
Towing Requirements — Tires
Do not attempt to tow a trailer while using a
compact spare tire.
Do not drive more than 50 mph (80 km/h) when towing while using a full size spare tire.
Proper tire inflation pressures are essential
to the safe and satisfactory operation of your
vehicle.
Check the trailer tires for proper tire inflation
pressures before trailer usage.
Check for signs of tire wear or visible tire
damage before towing a trailer.
For the proper tire replacement procedures.
Replacing tires with a higher load carrying
capacity will not increase the vehicle's GVWR
and GAWR limits.
For further information Ú page 406.
Towing Requirements — Trailer Brakes
Do not interconnect the hydraulic brake
system or vacuum system of your vehicle
with that of the trailer. This could cause inad -
equate braking and possible personal injury.
An electronically actuated trailer brake
controller is required when towing a trailer
with electronically actuated brakes. When
towing a trailer equipped with a hydraulic
surge actuated brake system, an electronic
brake controller is not required.
Trailer brakes are recommended for trailers
over 1,000 lbs (453 kg) and required for
trailers in excess of 2,000 lbs (907 kg).
WARNING!

Make certain that the load is secured in the
trailer and will not shift during travel. When
trailering cargo that is not fully secured,
dynamic load shifts can occur that may be diffi -
cult for the driver to control. You could lose
control of your vehicle and have a collision.

When hauling cargo or towing a trailer, do
not overload your vehicle or trailer. Over -
loading can cause a loss of control, poor
performance or damage to brakes, axle,
engine, transmission, steering, suspension,
chassis structure or tires.
Safety chains must always be used
between your vehicle and trailer. Always
connect the chains to the hook retainers of
the vehicle hitch. Cross the chains under
the trailer tongue and allow enough slack
for turning corners.
Vehicles with trailers should not be parked
on a grade. When parking, apply the
parking brake on the tow vehicle. Put the
tow vehicle transmission in PARK. For
four-wheel drive vehicles, make sure the
transfer case is not in NEUTRAL. Always,
block or "chock" the trailer wheels.
GCWR must not be exceeded.
Total weight must be distributed between
the tow vehicle and the trailer such that the
following four ratings are not exceeded :
GVWR
GTW
GAWR
Tongue weight rating for the trailer
hitch utilized.
WARNING! (Continued)

21_DPF_OM_EN_USC_t.book Page 206

STARTING AND OPERATING211
This light check sequence will continue for a
total of five minutes.
The sequence will only activate if the following
conditions are met:
Vehicle is equipped with the Trailer Tow
Package
Vehicle is in PARK
Vehicle is not in motion
Ignition in ACC or RUN
Remote start is inactive
Brakes are not applied
Left turn signal is not applied
Right turn signal not applied
Hazard switch is not applied
The sequence will cancel if any of the following
conditions occur:
Brakes are applied
Vehicle is shifted from PARK
Vehicle is no longer stationary
Left turn signal activated from stalk
Right turn signal is activated from stalk
Hazard switch is activated
Any button on the key fob is pushed
Ignition button is pushed
High Beam stalk position is changed
Sequence is canceled in the instrument
cluster
TOWING TIPS
Before setting out on a trip, practice turning,
stopping, and backing up the trailer in an area
located away from heavy traffic.
Automatic Transmission
The DRIVE range can be selected when towing.
The transmission controls include a drive
strategy to avoid frequent shifting when towing.
However, if frequent shifting does occur while in
DRIVE, select TOW/HAUL mode or select a lower
gear range (using the Electronic Range Select
(ERS) shift control). NOTE:
Using TOW/HAUL mode or selecting a lower
gear range (using the ERS shift control) while
operating the vehicle under heavy loading
conditions will improve performance and
extend transmission life by reducing excessive
shifting and heat build-up. This action will also
provide better engine braking.
Six-Speed Automatic Transmission Only
When towing a loaded trailer up steep grades
at low speeds (20 mph [32 km/h] or below),
holding your vehicle in FIRST gear (using the
ERS shift control) can help to avoid
transmission overheating.
If you regularly tow a trailer for more than
45 minutes of continuous operation, then
change the automatic transmission fluid and
filter(s) as specified for "police, taxi, fleet, or
frequent trailer towing." Ú
page 354.
NOTE:
Check the automatic transmission fluid level
before towing (Six-speed automatic only).
4

21_DPF_OM_EN_USC_t.book Page 211