2020 Ram 2500 cooling

208SAFETY
(Continued)
(Continued)
Transporting Pets
Air Bags deploying in the front seat could harm
your pet. An unrestrained pet will be thrown
about and possibly injured, or injure a
passenger during panic braking or in a collision.
Pets should be restrained in the rear seat (if
equipped) in pet harnesses or pet carriers that
are secured by seat belts.
SAFETY TIPS
Transporting Passengers
NEVER TRANSPORT PASSENGERS IN THE
CARGO AREA.
Exhaust Gas The best protection against carbon monoxide
entry into the vehicle body is a properly main
-
tained engine exhaust system.
Whenever a change is noticed in the sound of
the exhaust system, when exhaust fumes can
be detected inside the vehicle, or when the
underside or rear of the vehicle is damaged,
have a competent mechanic inspect the
complete exhaust system and adjacent body
areas for broken, damaged, deteriorated, or
mispositioned parts. Open seams or loose
connections could permit exhaust fumes to
seep into the passenger compartment. In addi -
tion, inspect the exhaust system each time the
vehicle is raised for lubrication or oil change.
Replace as required.
WARNING!
Do not leave children or animals inside
parked vehicles in hot weather. Interior
heat build-up may cause serious injury or
death.
It is extremely dangerous to ride in a cargo
area, inside or outside of a vehicle. In a
collision, people riding in these areas are
more likely to be seriously injured or killed.
Do not allow people to ride in any area of
your vehicle that is not equipped with seats
and seat belts.
Be sure everyone in your vehicle is in a seat
and using a seat belt properly.
WARNING!
Exhaust gases can injure or kill. They contain
carbon monoxide (CO), which is colorless and
odorless. Breathing it can make you
unconscious and can eventually poison you.
To avoid breathing (CO), follow these safety
tips:
Do not run the engine in a closed garage or
in confined areas any longer than needed
to move your vehicle in or out of the area.
If you are required to drive with the trunk/
liftgate/rear doors open, make sure that all
windows are closed and the climate control
BLOWER switch is set at high speed. DO
NOT use the recirculation mode.
WARNING! (Continued)
If it is necessary to sit in a parked vehicle
with the engine running, adjust your
heating or cooling controls to force outside
air into the vehicle. Set the blower at high
speed.
WARNING! (Continued)

20_DJD2_OM_EN_USC_t.book Page 208

226STARTING AND OPERATING
Idle Shutdown
This feature can be enabled so that the truck
will automatically shutdown when the truck has
been idling for a set period of time when the
engine is at operating temperature. Idle time
can be set in 5 minute increments between 5
and 60 minutes. See an authorized dealer to
enable this feature.
NOTE:
The idle shut down timer is disabled while the
PTO is active.
Programmable Maximum Vehicle Speed
This feature allows the owner to set a maximum
vehicle speed for the vehicle. The 2500 and
3500 Series maximum vehicle speed can be set
between 40 mph (64 km/h) and 87 mph
(140 km/h). The 4500/5500 Series maximum
vehicle speed can be set between 40 mph (64 km/h) and 85 mph (136 km/h). See an
authorized dealer to enable this feature.
NOTE:
DO NOT set the maximum vehicle speed to a
value greater than what the vehicle tires are
rated for.
Operating Precautions
Avoid Overheating The Engine
The temperature of the engine coolant (anti
-
freeze) (a mixture of 50% ethylene-glycol and
50% water) must not exceed the normal range
of the temperature gauge 240°F (116°C) with
a 21 psi (145 kPa) coolant pressure cap.
Usually the engine coolant (antifreeze)
temperature indicated during operation will be
to the left of center in the normal range of the
gauge.
Avoid Low Coolant Temperature Operation
Continual operation at low engine coolant (anti -
freeze) temperature below the normal range on
the gauge 140°F (60°C) can be harmful to the
engine. Low engine coolant (antifreeze)
temperature can cause incomplete combustion
which allows carbon and varnish to form on
piston rings and injector nozzles. Also, the
unburned fuel can enter the crankcase, diluting
the lubricating oil and causing rapid wear to the
engine.
Cooling System Tips
To reduce potential for engine and transmission
overheating in high ambient temperature condi -
tions, take the following actions:
City Driving — When stopped, shift the trans -
mission into NEUTRAL and increase engine
idle speed.
Highway Driving — Reduce your speed.
City Traffic
Maximum GCWR -Three
Highway Speeds Maximum GCWR -Four
Uphill Grade Maximum GCWR HotFive
Driving Condition Load Turbocharger Temperature Idle Time (min.) Before Engine
Shutdown

20_DJD2_OM_EN_USC_t.book Page 226

240STARTING AND OPERATING
engine may be started in this range. 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 underdrive first, second, and third gears, direct fourth gear and overdrive fifth
and sixth 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, trav
-
eling into strong head winds, or while towing a
heavy trailer), 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 conditions, using a lower gear
range will improve performance and extend
transmission life by reducing excessive shifting
and heat buildup.
If the transmission temperature exceeds
normal operating limits, the powertrain
controller will modify the transmission shift
schedule and expand the range of torque
converter clutch engagement. This is done to
prevent transmission damage due to over -
heating.
If the transmission becomes extremely hot or is
in danger of overheating, the “Transmission
Temperature Warning Light” may illuminate and
the transmission may operate differently until
the transmission cools down. NOTE:
Use caution when operating a heavily loaded
vehicle at low speeds (such as towing a trailer
up a steep grade, or in stop-and-go traffic)
during hot weather. In these conditions, torque
converter slip can impose a significant addi
-
tional heat load on the cooling system. Down -
shifting the transmission to the lowest possible
gear (when climbing a grade), or shifting to
NEUTRAL (when stopped in heavy traffic) can
help to reduce this excess heat generation.
During cold temperatures, transmission opera -
tion may be modified depending on engine and
transmission temperature as well as vehicle
speed. This feature improves warm up time of
the engine and transmission to achieve
maximum efficiency. Engagement of the torque
converter clutch is inhibited until the transmis -
sion fluid is warm refer to the “Note” under
“Torque Converter Clutch” in this section. On
Pickup models with 68RFE transmission, top
overdrive gear is also inhibited until the trans -
mission fluid is warm, and during extremely cold
temperatures (-16°F [-27°C] or below), opera -
tion may briefly be limited to first and direct
gears only. On trucks with AS69RC transmis -
sion, fifth and sixth gears may be inhibited
briefly on cold starts below 41°F (5°C), and
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.

20_DJD2_OM_EN_USC_t.book Page 240

260STARTING AND OPERATING
Driving Through Water
Extreme care should be taken crossing any type
of water. Water crossings should be avoided if
possible and only be attempted when neces -
sary, in a safe responsible manner. You should
only drive through areas which are designated
and approved. You should tread lightly and
avoid damage to the environment. You should
know your vehicle's abilities and be able to
recover it if something goes wrong. You should
never stop or shut a vehicle off when crossing
deep water unless you ingested water into the
engine air intake. If the engine stalls do not
attempt to restart it. Determine if it has ingested
water first. The key to any crossing is low and
slow. You want to use FIRST gear in 4WD LOW
and proceed very slowly with a constant slow
speed (3-5 mph [5–8 km/h] maximum) and
light throttle. Keep the vehicle moving; do not
try to accelerate through the crossing. After
crossing any water higher than the bottom of
the axle differentials, you should inspect all of
the vehicle fluids for signs of water ingestion.
Before You Cross Any Type Of Water – As you
approach any type of water you need to
determine if you can cross it safely and
responsibly. If necessary, get out and walk
through the water or probe it with a stick. You
need to be sure of its depth, approach angle,
current and bottom condition. Be careful of
murky or muddy waters, check for hidden
obstacles. Make sure you will not be
intruding on any wildlife and you can recover
the vehicle if necessary. The key to a safe
crossing is the water depth, current and
bottom conditions. On soft bottoms the
vehicle will sink in, effectively increasing the
water level on the vehicle. Be sure to
consider this when determining the depth
and the ability to safely cross.
Crossing Puddles, Pools, Flooded Areas Or
Other Standing Water – Puddles, pools,
flooded or other standing water areas
normally contain murky or muddy waters.
These water types normally contain hidden
obstacles and make it difficult to determine
an accurate water depth, approach angle,
and bottom condition. Murky or muddy water
holes are where you want to hook up tow
straps prior to entering. This makes for a
faster, cleaner and easier vehicle recovery. If
you are able to determine you can safely
cross, than proceed using the low and slow
method.
Crossing Ditches, Streams, Shallow Rivers Or
Other Flowing Water – Flowing water can be
extremely dangerous. Never attempt to cross
a fast running stream or river even in shallow
water. Fast moving water can easily push
your vehicle downstream sweeping it out of
control. Even in very shallow water, a high
current can still wash the dirt out from
CAUTION!
Water ingestion into the axles, transmission,
transfer case, engine or vehicle interior can
occur if you drive too fast or through too deep
of water. Water can cause permanent
damage to engine, driveline or other vehicle
components and your brakes will be less
effective once wet and/or muddy.
CAUTION!
Muddy waters can reduce the cooling system
effectiveness by depositing debris onto the
radiator.

20_DJD2_OM_EN_USC_t.book Page 260

STARTING AND OPERATING329
Speed Control — If Equipped
Do not use on hilly terrain or with heavy
loads.
When using the Speed Control, if you experi -
ence speed drops greater than 10 mph
(16 km/h), disengage until you can get back
to cruising speed.
Use Speed Control in flat terrain and with
light loads to maximize fuel efficiency.
Cooling System
To reduce potential for engine and transmission
overheating, take the following actions:
City Driving
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase
engine idle speed.
Highway Driving
Reduce speed.
Temporarily turn off air conditioning.
Air Suspension System
To aid in attaching/detaching the trailer from
the vehicle, the air suspension system can be
used. Refer to “Air Suspension System” in “Starting And Operating” for further informa
-
tion.
NOTE:
The vehicle must remain in the engine running
position while attaching a trailer for proper
leveling of the air suspension system.
SNOWPLOW
Snowplow Prep Packages are available as a
factory installed option. These packages
include components necessary to equip your
vehicle with a snowplow.
NOTE:
Before installation of a snowplow it is highly
recommended that the owner/installer obtain
and follow the recommendations contained
within the current Body Builders Guide. See
your authorized dealer, installer or snowplow
manufacturer for this information. There are
unique electrical systems that must be
connected to properly ensure operator safety
and prevent overloading vehicle systems.
Before Plowing
Check the hydraulic system for leaks and
proper fluid level.
Check the mounting bolts and nuts for proper
tightness.
Check the runners and cutting edge for
excessive wear. The cutting edge should be
¼ to ½ inches (6 cm to 1.2 cm) above ground
in snow plowing position.
Check that snowplow lighting is connected
and functioning properly.
WARNING!
Attaching a snowplow to this vehicle could
adversely affect performance of the airbag
system in a collision. Do not expect that the
airbag will perform as described earlier in this
manual.
CAUTION!
The “Lamp Out” indicator could illuminate if
exterior lamps are not properly installed.
5

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IN CASE OF EMERGENCY363
Preparations For Jump Start
The battery in your vehicle is located in the front
of the engine compartment, behind the driver
side headlight assembly.
NOTE:
If you have a diesel engine, you may have two
batteries, however jump start off the driver
side battery.
The positive battery post may be covered with
a protective cap if equipped. Lift up on the
cap to gain access to the positive battery
post. Do not jump off fuses. Only jump
directly off positive post which has a positive
(+) symbol on or around the post.

Positive Battery Post
1. Apply the parking brake, shift the auto
-
matic transmission into PARK and turn the
ignition OFF.

2. Turn off the heater, radio, and all unneces -
sary electrical accessories.
3. If using another vehicle to jump start the battery, park the vehicle within the jumper
cables’ reach, apply the parking brake and
make sure the ignition is OFF.
Jump Starting Procedure
Connecting The Jumper Cables
WARNING!
Take care to avoid the radiator cooling fan
whenever the hood is raised. It can start
anytime the ignition switch is ON. You can
be injured by moving fan blades.
Remove any metal jewelry such as rings,
watch bands and bracelets that could
make an inadvertent electrical contact. You
could be seriously injured.
Batteries contain sulfuric acid that can
burn your skin or eyes and generate
hydrogen gas which is flammable and
explosive. Keep open flames or sparks
away from the battery.
WARNING!
Do not allow vehicles to touch each other as
this could establish a ground connection and
personal injury could result.
WARNING!
Failure to follow this jump starting procedure
could result in personal injury or property
damage due to battery explosion.
CAUTION!
Failure to follow these procedures could
result in damage to the charging system of
the booster vehicle or the discharged vehicle.
6

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IN CASE OF EMERGENCY367
To Reset The Manual Park Release:

1. Push the locking tab to the right, to unlock
the lever.

2. Rotate the Manual Park Release lever forward to its original position, until the
locking tab snaps into place to secure the
lever.
3. Pull gently on the tether strap to confirm that the lever is locked in its stowed posi-
tion.
4. Re-install the access cover.
IF YOUR ENGINE OVERHEATS
In any of the following situations, you can
reduce the potential for overheating by taking
the appropriate action.
On the highways — slow down.
In city traffic — while stopped, place the trans -
mission in NEUTRAL, but do not increase the
engine idle speed while preventing vehicle
motion with the brakes. NOTE:
There are steps that you can take to slow down
an impending overheat condition:
If your Air Conditioner (A/C) is on, turn it off.
The A/C system adds heat to the engine
cooling system and turning the A/C off can
help remove this heat.
You can also turn the temperature control to
maximum heat, the mode control to floor and
the blower control to high. This allows the
heater core to act as a supplement to the
radiator and aids in removing heat from the
engine cooling system.
FREEING A STUCK VEHICLE
If your vehicle becomes stuck in mud, sand, or
snow, it can often be moved using a rocking
motion. Turn the steering wheel right and left to
clear the area around the front wheels. Then
shift back and forth between DRIVE (D) and
REVERSE (R), while gently pressing the acceler
-
ator. Use the least amount of accelerator pedal
pressure that will maintain the rocking motion,
without spinning the wheels or racing the
engine.
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
try to open a cooling system pressure cap
when the radiator or coolant bottle is hot.
CAUTION!
Driving with a hot cooling system could
damage your vehicle. If the temperature
gauge reads HOT (H), pull over and stop the
vehicle. Idle the vehicle with the air
conditioner turned off until the pointer drops
back into the normal range. If the pointer
remains on HOT (H), and you hear continuous
chimes, turn the engine off immediately and
call for service.
6

20_DJD2_OM_EN_USC_t.book Page 367

SERVICING AND MAINTENANCE381
NOTE:
Using white lithium grease, lubricate the door
hinge roller pivot joints twice a year to prevent
premature wear.
At Every Oil Change Interval As Indicated
By Oil Change Indicator System:
Change oil and filter.
Rotate the tires. Rotate at the first sign of
irregular wear, even if it occurs before the
oil indicator system turns on.
Inspect battery and clean and tighten termi -
nals as required.
Inspect the CV/Universal joints.
Inspect brake pads, shoes, rotors, drums,
hoses and park brake.
Inspect engine cooling system protection
and hoses.
Inspect exhaust system.
At Every Oil Change Interval As Indicated
By Oil Change Indicator System:
Inspect engine air cleaner if using in dusty
or off-road conditions. If required, replace
air cleaner filter.
Inspect and replace the Evaporative
System Fresh Air Filter as necessary,
replacement may be more frequent if
vehicle is operated in extreme dusty condis -
tions.
At Every Oil Change Interval As Indicated
By Oil Change Indicator System:
7

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