key Ram 3500 2020 Workshop Manual

STARTING AND OPERATING223
(Continued)
STARTING FLUIDS
The engine is equipped with an automatic
electric air preheating system. If the
instructions in this manual are followed, the
engine should start in all conditions.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the engine is
operating:
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine oil pressure is above 10 psi (69 kPa)
at idle.
Voltmeter operation:
The voltmeter may show a gauge fluctuation at
various engine temperatures. This cycling
operation is caused by the post-heat cycle of the
intake manifold heater system. The number of
cycles and the length of the cycling operation is
controlled by the engine control module.
Post-heat operation can run for several
minutes, and then the electrical system and
voltmeter needle will stabilize.
The cycling action will cause temporary
dimming of the headlamps, interior lamps, and
also a noticeable reduction in blower motor
speed.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
WARNING!
Starting fluids or flammable liquids must
never be used in the Cummins diesel engine
(see Warning label). Never pour diesel fuel,
flammable liquid, starting fluids (ether) into
the air cleaner canister, air intake piping, or
turbocharger inlet in an attempt to start the
vehicle. This could result in a flash fire and
explosion causing serious personal injury and
engine damage.
WARNING!

Do not leave children or animals inside
parked vehicles in hot weather. Interior heat
build-up may cause serious injury or death.
When leaving the vehicle, always make sure
the keyless ignition node is in the “OFF”
mode, remove the key fob from the vehicle
and lock the vehicle.
Never leave children alone in a vehicle, or
with access to an unlocked vehicle. Allowing
children to be in a vehicle unattended is
dangerous for a number of reasons. A child
or others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the gear
selector.
Do not leave the key fob in or near the
vehicle, or in a location accessible to chil -
dren, and do not leave the ignition of a
vehicle equipped with Keyless Enter-N-Go in
the ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.

WARNING! (Continued)
5

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232STARTING AND OPERATING
DIESEL EXHAUST BRAKE — ENGINE
BRAKING (IF EQUIPPED)
The purpose of the exhaust brake (engine
braking) feature is to supply negative (braking)
torque from the engine. Typically, the engine
braking is used for, but not limited to, vehicle
towing applications where vehicle braking can
be achieved by the internal engine power,
thereby sparing the mechanical brakes of the
vehicle.
Benefits of the exhaust brake are:
Vehicle driving control.
Reduced brake fade.
Longer brake life.
Faster cab warm-up.
The exhaust brake feature will only function
when the driver toggles it on by pushing the
exhaust brake button until the “Exhaust Brake
Indicator” is illuminated. Normal (Full Strength)
exhaust brake mode is indicated by a yellow
“Exhaust Brake Indicator”.
Exhaust Brake Switch

Once the “Exhaust Brake Indicator” is
illuminated and the vehicle is moving faster
than 5 mph (8 km/h); the exhaust brake will
automatically operate when the driver removes
pressure from the accelerator pedal. Exhaust
braking is most effective when the engine RPM
is higher. The automatic transmission will
downshift more aggressively in TOW/HAUL
mode when the exhaust brake is enabled to
increase brake performance.
Do not leave the key fob in or near the
vehicle, or in a location accessible to chil-
dren, and do not leave a vehicle equipped
with Keyless Enter-N-Go in the ACC or ON/
RUN mode. A child could operate power
windows, other controls, or move the
vehicle.
Be sure the parking brake is fully disen -
gaged before driving; failure to do so can
lead to brake failure and a collision.
Always fully apply the parking brake when
leaving your vehicle or it may roll and cause
damage or injury. Also, be certain to leave
the transmission in PARK. Failure to do so
may cause the vehicle to roll and cause
damage or injury.
CAUTION!
If the Brake System Warning Light remains on
with the parking brake released, a brake
system malfunction is indicated. Have the
brake system serviced by an authorized
dealer immediately.
WARNING! (Continued)

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234STARTING AND OPERATING
(Continued)
(Continued)
NOTE:
You must press and hold the brake pedal while
shifting out of PARK.
IGNITION PARK INTERLOCK
This vehicle is equipped with an Ignition Park
Interlock which requires the transmission to be
in PARK before the ignition can be turned to the
OFF mode. This helps the driver avoid
inadvertently leaving the vehicle without placing
the transmission in PARK. This system also
locks the transmission in PARK whenever the
ignition is in the OFF mode.
NOTE:
The transmission is NOT locked in PARK when
the ignition is in the ACC mode (even though the
engine will be off). Ensure that the transmission
is in PARK, and the ignition is OFF (not in ACC
mode) before exiting the vehicle.
It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing
the brake pedal, the vehicle could accel -
erate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and your
foot is firmly pressing the brake pedal.
Unintended movement of a vehicle could
injure those in or near the vehicle. As with
all vehicles, you should never exit a vehicle
while the engine is running. Before exiting a
vehicle, always come to a complete stop,
then apply the parking brake, shift the
transmission into PARK, and turn the igni -
tion OFF. When the ignition is in the OFF
mode, the transmission is locked in PARK,
securing the vehicle against unwanted
movement.
When exiting the vehicle, always make sure
the ignition is in the OFF mode, remove the
key fob from the vehicle, and lock the
vehicle.
WARNING! (Continued)
Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended is dangerous for a number of
reasons. A child or others could be seriously
or fatally injured. Children should be
warned not to touch the parking brake,
brake pedal or the transmission gear
selector.
Do not leave the key fob in or near the
vehicle (or in a location accessible to chil -
dren), and do not leave the ignition in the
ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.
CAUTION!
Damage to the transmission may occur if the
following precautions are not observed:
Shift into or out of PARK or REVERSE only
after the vehicle has come to a complete
stop.
WARNING! (Continued)
Do not shift between PARK, REVERSE,
NEUTRAL, or DRIVE when the engine is
above idle speed.
Before shifting into any gear, make sure
your foot is firmly pressing the brake pedal.
CAUTION! (Continued)

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236STARTING AND OPERATING
(Continued)
(Continued)
PARK (P)
This range supplements the parking brake by
locking the transmission. The engine can be
started in this range. Never attempt to use
PARK while the vehicle is in motion. Apply the
parking brake when exiting the vehicle in this
range.
When parking on a level surface, you may shift
the transmission into PARK first, and then apply
the parking brake.
When parking on a hill, apply the parking brake
before shifting the transmission to PARK. As an
added precaution, turn the front wheels toward
the curb on a downhill grade and away from the
curb on an uphill grade.
NOTE:
On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
When exiting the vehicle, always:
Apply the parking brake.
Shift the transmission into PARK.
Turn the engine off.
Remove the key fob.
WARNING!
Never use the PARK position as a substi
-
tute for the parking brake. Always apply the
parking brake fully when exiting the vehicle
to guard against vehicle movement and
possible injury or damage.
Your vehicle could move and injure you and
others if it is not in PARK. Check by trying to
move the transmission gear selector out of
PARK with the brake pedal released. Make
sure the transmission is in PARK before
exiting the vehicle.
The transmission may not engage PARK if
the vehicle is moving. Always bring the
vehicle to a complete stop before shifting to
PARK, and verify that the transmission gear
position indicator solidly indicates PARK (P)
without blinking. Ensure that the vehicle is
completely stopped, and the PARK position
is properly indicated, before exiting the
vehicle.
It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing
the brake pedal, the vehicle could accel -
erate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and your
foot is firmly pressing the brake pedal.

Unintended movement of a vehicle could
injure those in or near the vehicle. As with all
vehicles, you should never exit a vehicle
while the engine is running. Before exiting a
vehicle, always come to a complete stop,
then apply the parking brake, shift the trans -
mission into PARK, and turn the ignition OFF.
When the ignition is in the OFF mode, the
transmission is locked in PARK, securing the
vehicle against unwanted movement.
When exiting the vehicle, always make sure
the ignition is in the OFF mode, remove the
key fob from the vehicle, and lock the
vehicle.

WARNING! (Continued)

20_DJD2_OM_EN_USC_t.book Page 236

STARTING AND OPERATING237
The following indicators should be used to
ensure that you have properly engaged the
transmission into the PARK position:
Look at the transmission gear position
display and verify that it indicates the PARK
position (P), and is not blinking.
With brake pedal released, verify that the
gear selector will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward.
Shift into REVERSE only after the vehicle has
come to a complete stop.
NEUTRAL (N)
Use this range when the vehicle is standing for
prolonged periods with the engine running.
Apply the parking brake and shift the
transmission into PARK if you must exit the
vehicle. DRIVE (D)
This range should be used for most city and
highway driving. It provides the smoothest
upshifts and downshifts, and the best fuel
economy. The transmission automatically
upshifts through all forward gears. The DRIVE
position provides optimum driving
characteristics under all normal operating
conditions.
When frequent transmission shifting occurs
(such as when operating the vehicle under
heavy loading conditions, in hilly terrain,
traveling into strong head winds, or while towing
a heavy trailer), select TOW/HAUL mode or use
the Electronic Range Select (ERS) shift control
refer to "Electronic Range Select [ERS]
Operation" in this section for further information
to select a lower gear range. Under these

Never leave children alone in a vehicle, or
with access to an unlocked vehicle. Allowing
children to be in a vehicle unattended is
dangerous for a number of reasons. A child
or others could be seriously or fatally injured.
Children should be warned not to touch the
parking brake, brake pedal or the transmis
-
sion gear selector.

Do not leave the key fob in or near the
vehicle (or in a location accessible to chil -
dren), and do not leave the ignition in the
ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.
CAUTION!
DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range,
as this can damage the drivetrain.
Before moving the transmission gear
selector out of PARK, you must start the
engine, and also press the brake pedal.
Otherwise, damage to the gear selector
could result.
WARNING! (Continued)
WARNING!
Do not coast in NEUTRAL and never turn off
the ignition to coast down a hill. These are
unsafe practices that limit your response to
changing traffic or road conditions. You might
lose control of the vehicle and have a
collision.
CAUTION!
Towing the vehicle, coasting, or driving for any
other reason with the transmission in
NEUTRAL can cause severe transmission
damage. Refer to “Recreational Towing” in
“Starting And Operating” and “Towing A
Disabled Vehicle” in “In Case Of Emergency”
for further information.
5

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240STARTING AND OPERATING
(Continued)
The electronically-controlled transmission
provides a precise shift schedule. The
transmission electronics are self-calibrating;
therefore, the first few shifts on a new vehicle
may be somewhat abrupt. This is a normal
condition, and precision shifts will develop
within a few hundred miles (kilometers).
Only shift from DRIVE to PARK or REVERSE
when the accelerator pedal is released and the
vehicle is stopped. Be sure to keep your foot on
the brake pedal when shifting between these
gears.
The transmission gear selector has only PARK,
REVERSE, NEUTRAL, and DRIVE shift positions.
Manual downshifts can be made using the
Electronic Range Select (ERS) shift control.
Pressing the ERS (-/+) switches (on the steering
wheel) while in the DRIVE position will select the
highest available transmission gear, and will
display that gear limit in the instrument cluster
as 1, 2, 3, etc. Refer to "Electronic Range Select
(ERS) Operation" in this section for further
information. Some models will display both the
selected gear limit, and the actual current gear,
while in ERS mode.Gear Ranges
Do not depress the accelerator pedal when
shifting from PARK or NEUTRAL into another
gear range.
NOTE:
After selecting any gear range, wait a moment
to allow the selected gear to engage before
accelerating. This is especially important when
the engine is cold.
PARK (P)
This range supplements the parking brake by
locking the transmission. The engine can be
started in this range. Never attempt to use
PARK while the vehicle is in motion. Apply the
parking brake when exiting the vehicle in this
range.
When parking on a level surface, you may shift
the transmission into PARK first, and then apply
the parking brake.
When parking on a hill, apply the parking brake
before shifting the transmission to PARK,
otherwise the load on the transmission locking
mechanism may make it difficult to move the
gear selector out of PARK. As an added precaution, turn the front wheels toward the
curb on a downhill grade and away from the
curb on an uphill grade.
When exiting the vehicle, always:
Apply the parking brake.
Shift the transmission into PARK.
Turn the engine off.
Remove the key fob.
NOTE:
On four-wheel drive vehicles be sure that the
transfer case is in a drive position.
WARNING!
Never use the PARK position as a substi -
tute for the parking brake. Always apply the
parking brake fully when exiting the vehicle
to guard against vehicle movement and
possible injury or damage.
Your vehicle could move and injure you and
others if it is not in PARK. Check by trying to
move the gear selector out of PARK with the
brake pedal released. Make sure the trans -
mission is in PARK before exiting the
vehicle.

20_DJD2_OM_EN_USC_t.book Page 240

STARTING AND OPERATING241
(Continued)
(Continued)
The following indicators should be used to
ensure that you have properly engaged the
transmission into the PARK position:
When shifting into PARK, pull the gear
selector toward you and move it all the way
counterclockwise until it stops.
Release the gear selector and make sure it is
fully seated in the PARK gate.
Look at the transmission gear position
display and verify that it indicates the PARK
position (P).
With brake pedal released, verify that the
gear selector will not move out of PARK.
REVERSE (R)
This range is for moving the vehicle backward.
Shift into REVERSE only after the vehicle has
come to a complete stop.
It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing
the brake pedal, the vehicle could accel -
erate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and your
foot is firmly pressing the brake pedal.
Unintended movement of a vehicle could
injure those in or near the vehicle. As with
all vehicles, you should never exit a vehicle
while the engine is running. Before exiting a
vehicle, always come to a complete stop,
then apply the parking brake, shift the
transmission into PARK, turn the engine off,
and remove the key fob. When the ignition
is in the LOCK/OFF (key removal) position
(or, with Keyless Enter-N-Go, when the igni -
tion is in the OFF mode), the transmission is
locked in PARK, securing the vehicle
against unwanted movement.
When leaving the vehicle, always make
sure the ignition is in the OFF mode,
remove the key fob from the vehicle, and
lock the vehicle.
WARNING! (Continued)
Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended is dangerous for a number of
reasons. A child or others could be seriously
or fatally injured. Children should be
warned not to touch the parking brake,
brake pedal or the transmission gear
selector.
Do not leave the key fob in or near the
vehicle (or in a location accessible to chil -
dren), and do not leave the ignition (in a
vehicle equipped with Keyless Enter-N-Go)
in the ACC or ON/RUN mode. A child could
operate power windows, other controls, or
move the vehicle.
CAUTION!
Before moving the transmission gear
selector out of PARK, you must turn the igni -
tion to the ON/RUN mode, and also press
the brake pedal. Otherwise, damage to the
gear selector could result.
WARNING! (Continued)
DO NOT race the engine when shifting from
PARK or NEUTRAL into another gear range,
as this can damage the drivetrain.
CAUTION! (Continued)
5

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246STARTING AND OPERATING
AUXILIARY SWITCHES — IF EQUIPPED
There can be up to six auxiliary switches located
in the lower switch bank of the instrument panel
which can be used to power various electronic
devices and PTO (Power Take Off) – If Equipped.
If Power Take Off is equipped, it will take the
place of the sixth Auxiliary switch. Connections
to the switches are found under the hood in the
connectors attached to the auxiliary Power
Distribution Center.
You have the ability to configure the
functionality of the auxiliary switches via the
instrument cluster display. All switches can now
be configured for setting the switch type
operation to latching or momentary, power
source of either battery or ignition, and ability to
hold last state across key cycles.
NOTE:
Holding last state conditions are met when
switch type is set to latching and power source
is set to ignition.
For further information on using the auxiliary
switches, please refer to the Ram Body Builders
Guide by accessing www.rambodybuilder.com
and choosing the appropriate links.
ACTIVE NOISE CANCELLATION
Your vehicle is equipped with an Active Noise
Cancellation system that cannot be turned off.
This system is designed to address exhaust and
engine noise. The system relies on four
microphones embedded in the headliner, which
monitor exhaust and engine noise, and assists
an onboard frequency generator, which creates
counteracting sound waves in the audio
system’s speakers. This helps keep the vehicle
quiet at idle and during drive. The system is
deactivated when the windows are rolled down.
FOUR-WHEEL DRIVE OPERATION — IF
EQUIPPED
Four-wheel drive trucks are equipped with
either a manually shifted transfer case or an
electronically shifted transfer case. Refer to the
operating instructions for your transfer case,
located in this section for further information.
ELECTRONICALLY SHIFTED TRANSFER
C
ASE (EIGHT SPEED TRANSMISSION) —
I
F EQUIPPED
This is an electronic shift transfer case and is
operated by the 4WD Control Switch (Transfer
Case Switch), which is located on the
instrument panel.

Four-Position Transfer Case

This electronically shifted transfer case
provides four mode positions:
Two-Wheel Drive High Range (2WD)
Four-Wheel Drive High Range (4WD HIGH)
Four-Wheel Drive Low Range (4WD LOW)
N (Neutral)

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262STARTING AND OPERATING
The Basics Of Off-Road Driving
You will encounter many types of terrain driving
off-road. You should be familiar with the terrain
and area before proceeding. There are many
types of surface conditions: hard packed dirt,
gravel, rocks, grass, sand, mud, snow and ice.
Every surface has a different effect on your
vehicle's steering, handling and traction.
Controlling your vehicle is one of the keys to
successful off-road driving, so always keep a
firm grip on the steering wheel and maintain a
good driving posture. Avoid sudden
accelerations, turns or braking. In most cases
there are no road signs, posted speed limits or
signal lights. Therefore you will need to use your
own good judgment on what is safe and what
isn't. When on a trail you should always be
looking ahead for surface obstacles and
changes in terrain. The key is to plan your future
driving route while remembering what you are
currently driving over.
When To Use Low Range
When driving off-road, shift into 4WD LOW for
additional traction or to improve handling and
control on slippery or difficult terrain. Due to the
lower gearing, low range will allow the engine to
operate in a higher power range. This will allow
you to idle over obstacles and down hills, with
improved control and less effort. Also, use 4WD
LOW in rain, ice, snow, mud, and sand to get
heavy loads rolling, improve traction, or
whenever 4WD HIGH traction will not do the job.
DRIVING IN SNOW, MUD AND SAND
There is a drastic reduction in traction when
driving in snow, mud or sand. The vehicle will be
less responsive to steering, acceleration and
braking inputs. Therefore you should accelerate
slowly, leave greater stopping distances and
avoid abrupt vehicle maneuvers. You want to
keep a slow constant steady pace. The key is to
maintain the vehicle's momentum.
Snow – In heavy snow or for additional
control and traction at slower speeds, shift
the transmission to a low gear and shift the
transfer case to 4WD LOW if necessary. Do
not shift to a lower gear than necessary to
maintain headway. Over-revving the engine
can spin the wheels and traction will be lost.
If you start to slow to a stop, try turning your
steering wheel no more than a quarter turn
quickly back and forth, while still applying
throttle. This will allow the tires to get a fresh
"bite" and help maintain your momentum.
Mud – Deep mud creates a great deal of
suction around the tires and is very difficult to
get through. You should use 4WD LOW with a
gear low enough to maintain your momentum
without shifting. If you start to slow to a stop,
try turning your steering wheel no more than
a quarter turn quickly back and forth for addi -
tional traction. Mud holes pose an increased
threat of vehicle damage and getting stuck.
WARNING!
Always wear your seat belt and firmly tie down
cargo. Unsecured cargo can become
projectiles in an off-road situation.
CAUTION!
Never park your vehicle over dry grass or
other combustible materials. The heat from
your vehicle exhaust system could cause a
fire.
CAUTION!
On icy or slippery roads, do not downshift at
high engine RPMs or vehicle speeds because
engine braking may cause skidding and loss
of control.

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STARTING AND OPERATING263
They are normally full of debris from previous
vehicles getting stuck. As a good practice
before entering any mud hole, get out and
determine how deep it is, if there are any
hidden obstacles and if the vehicle can be
safely recovered if stuck.
Sand – Soft sand is very difficult to travel
through with full tire pressure. When crossing
soft sandy spots in a trail, maintain your
vehicle's momentum and do not stop. The
key to driving in soft sand is using the appro -
priate tire pressure, accelerating slowly,
avoiding abrupt maneuvers and maintaining
the vehicle's momentum. If you are going to
be driving on large soft sandy areas or dunes,
reduce your tire pressure to a minimum of
15 psi (103 kPa) to allow for a greater tire
surface area. Reduced tire pressure will dras -
tically improve your traction and handling,
while driving on the soft sand, but you must
return the tires to normal air pressure before
driving on pavement or other hard surfaces.
Be sure you have a way to air the tires back
up prior to reducing the pressure.
CROSSING OBSTACLES (ROCKS AND
O
THER HIGH POINTS)
While driving off road, you will encounter many
types of terrain. These varying types of terrain
bring different types of obstacles. Before
proceeding review the path ahead to determine
the correct approach and your ability to safely
recover the vehicle if something goes wrong.
Keeping a firm grip on the steering wheel, bring
the vehicle to a complete stop and then inch the
vehicle forward until it makes contact with the
object. Apply the throttle lightly while holding a
light brake pressure and ease the vehicle up
and over the object.
Using A Spotter
There are many times where it is hard to see the
obstacle or determine the correct path.
Determining the correct path can be extremely
difficult when you are confronting many
obstacles. In these cases have someone guide
you over, through, or around the obstacle. Have
the person stand a safe distance in front of you
where they can see the obstacle, watch your
tires and undercarriage, and guide you through.
Crossing Large Rocks
When approaching large rocks, choose a path
which ensures you drive over the largest with
your tires. This will lift your undercarriage over
the obstacle. The tread of the tire is tougher and
thicker than the side wall and is designed to
take the abuse. Always look ahead and make
every effort to cross the large rocks with your
tires.
CAUTION!
Reduced tire pressures may cause tire
unseating and total loss of air pressure. To
reduce the risk of tire unseating, while at a
reduced tire pressure, reduce your speed and
avoid sharp turns or abrupt maneuvers.
WARNING!
Crossing obstacles can cause abrupt steering
system loading which could cause you to
loose control of your vehicle.
CAUTION!
Never attempt to straddle a rock that is
large enough to strike your axles or under -
carriage.
Never attempt to drive over a rock which is
large enough to contact the door sills.
5

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