cooling Ram 2500 2020 User Guide

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

20_DJD2_OM_EN_USC_t.book Page 329

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

20_DJD2_OM_EN_USC_t.book Page 363

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

20_DJD2_OM_EN_USC_t.book Page 381

390SERVICING AND MAINTENANCE
(Continued)
Inspection and service should also be performed anytime a malfunction is observed or suspected. Retain all receipts. Flush and replace power
steering fluid.
X
Flush and replace engine
coolant. *** X
1. Under no circumstances should oil change intervals exceed 15,000 miles (24,000 km) or 12 months or 500 Hours, whichever comes first.
2. Under no circumstances should the air cleaner filter element exceed 30,000 miles (48,000 km) or 24 months, whichever comes first.
3. Inspect the front and rear axle surfaces every 20,000 miles (32,000 km). If gear oil leakage is suspected, check the fluid level. If using your vehicle for police, taxi,
fleet, off-road or frequent trailer towing change the axle fluid every 20,000 miles (32,000 km).
Mileage or time passed
(whichever comes first):
7,500
15,000
22,500
30,000
37,500
45,000
52,500
60,000
67,500
75,000
82,500
90,000
97,500
105,000
112,500
120,000
127,500
135,000
142,500
150,000
Or Months: 6 12 18 24 30 36 42 48 54 60 66 72 78 84 90 96 102 108 114 120
Or Kilometers:
12,000
24,000
36,000
48,000
60,000
72,000
84,000
96,000
108,000
120,000
132,000
144,000
156,000
168,000
180,000
192,000
204,000
216,000
228,000
240,000
WARNING!
You can be badly injured working on or
around a motor vehicle. Do only service
work for which you have the knowledge and
the right equipment. If you have any doubt
about your ability to perform a service job,
take your vehicle to a competent mechanic.Failure to properly inspect and maintain
your vehicle could result in a component
malfunction and effect vehicle handling
and performance. This could cause an acci -
dent.
WARNING! (Continued)CAUTION!
***The manufacturer highly recommends
that all cooling system service, maintenance,
and repairs be performed by your local
authorized dealer.

20_DJD2_OM_EN_USC_t.book Page 390

SERVICING AND MAINTENANCE403
Accessory Drive Belt Inspection
When inspecting accessory drive belts, small
cracks that run across ribbed surface of belt
from rib to rib, are considered normal. These
are not a reason to replace belt. However,
cracks running along a rib (not across) are not
normal. Any belt with cracks running along a rib
must be replaced. Also have the belt replaced if
it has excessive wear, frayed cords or severe
glazing.
Accessory Belt (Serpentine Belt)

Conditions that would require replacement:
Rib chunking (one or more ribs has sepa -
rated from belt body)
Rib or belt wear
Longitudinal belt cracking (cracks between
two ribs)
Belt slips
“Groove jumping" (belt does not maintain
correct position on pulley)
Belt broken (note: identify and correct
problem before new belt is installed)
Noise (objectionable squeal, squeak, or
rumble is heard or felt while drive belt is in
operation) Some conditions can be caused by a faulty
component such as a belt pulley. Belt pulleys
should be carefully inspected for damage and
proper alignment.
Belt replacement on some models requires the
use of special tools, we recommend having your
vehicle serviced at an authorized dealer.
Draining Fuel/Water Separator Filter —
Diesel Engine
There are two fuel filter assemblies. One is
located on the driver's side of the engine. The
best access to this water drain valve is from
under the hood. The second one is on the under
body, located in front of the rear axle above the
drive shaft on pick-up models. The Chassis Cab
models second filter location is on the frame
behind the front axle. The best access to this
water drain valve is from under the vehicle.
WARNING!
Do not attempt to inspect an accessory
drive belt with vehicle running.
When working near the radiator cooling fan,
disconnect the fan motor lead. The fan is
temperature controlled and can start at any
time regardless of ignition mode. You could
be injured by the moving fan blades.
You can be badly injured working on or
around a motor vehicle. Only do service
work for which you have the knowledge and
the proper equipment. If you have any
doubt about your ability to perform a
service job, take your vehicle to a compe
-
tent mechanic.
CAUTION!
Do not drain the fuel/water separator filter
when the engine is running.
Diesel fuel will damage blacktop paving
surfaces. Drain the filter into an appro-
priate container.
7

20_DJD2_OM_EN_USC_t.book Page 403

SERVICING AND MAINTENANCE411
(Continued)
(Continued)
exhaust system inspected each time the vehicle
is raised for lubrication or oil change. Replace
as required.
Under normal operating conditions, the cata-
lytic converter will not require maintenance.
However, it is important to keep the engine
properly tuned to ensure proper catalyst opera-
tion and prevent possible catalyst damage.
NOTE:
Intentional tampering with emissions control
systems can result in civil penalties being
assessed against you.
In unusual situations involving grossly malfunc -
tioning engine operation, a scorching odor may
suggest severe and abnormal catalyst over -
heating. If this occurs, stop the vehicle, turn off the engine and allow it to cool. Service,
including a tune-up to manufacturer's specifica-
tions, should be obtained immediately.
To minimize the possibility of catalytic converter
damage:
Do not interrupt the ignition when the transmis
-
sion is in gear and the vehicle is in motion.
Do not try to start the vehicle by pushing or
towing the vehicle.
Do not idle the engine with any ignition
components disconnected or removed, such
as when diagnostic testing, or for prolonged
periods during very rough idle or malfunc -
tioning operating conditions.
Cooling System
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, refer to “Safety Tips”
in “Safety” for further information.

A hot exhaust system can start a fire if you
park over materials that can burn. Such
materials might be grass or leaves coming
into contact with your exhaust system. Do
not park or operate your vehicle in areas
where your exhaust system can contact
anything that can burn.
CAUTION!
The catalytic converter requires the use of
unleaded fuel only. Leaded gasoline will
destroy the effectiveness of the catalyst as
an emissions control device and may seri-
ously reduce engine performance and
cause serious damage to the engine.
Damage to the catalytic converter can
result if your vehicle is not kept in proper
operating condition. In the event of engine
malfunction, particularly involving engine
misfire or other apparent loss of perfor -
mance, have your vehicle serviced
promptly. Continued operation of your
vehicle with a severe malfunction could
cause the converter to overheat, resulting
in possible damage to the converter and
vehicle.
CAUTION! (Continued)
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 open a
cooling system pressure cap when the radiator
or coolant bottle is hot.

7

20_DJD2_OM_EN_USC_t.book Page 411

412SERVICING AND MAINTENANCE
Engine Coolant Checks
Check the engine coolant (antifreeze) protec-
tion every 12 months (before the onset of
freezing weather, where applicable). If the
engine coolant (antifreeze) is dirty or rusty in
appearance, the system should be drained,
flushed and refilled with fresh coolant. Check
the front of the A/C condenser (if equipped) or
radiator for any accumulation of bugs, leaves,
etc. If dirty, clean by gently spraying water from
a garden hose vertically down the face of the
A/C condenser (if equipped) or the back of the
radiator core. Check the engine cooling system hoses for
brittle rubber, cracking, tears, cuts and tight
-
ness of the connection at the coolant recovery
bottle and radiator. Inspect the entire system
for leaks.
DO NOT REMOVE THE COOLANT PRESSURE CAP
WHEN THE COOLING SYSTEM IS HOT.
Cooling System — Drain, Flush And Refill
NOTE:
Some vehicles require special tools to add
coolant properly. Failure to fill these systems
properly could lead to severe internal engine
damage. If any coolant is needed to be added to
the system please contact an authorized
dealer.
If the engine coolant (antifreeze) is dirty or
contains visible sediment, have an authorized
dealer clean and flush with OAT coolant (anti -
freeze) (conforming to MS.90032).
Refer to the “Maintenance Plan” in this section
for the proper maintenance intervals.
Selection Of Coolant
Refer to “Fluids And Lubricants” in “Technical
Specifications” for further information. NOTE:
Mixing of engine coolant (antifreeze) other
than specified Organic Additive Technology
(OAT) engine coolant (antifreeze), may result
in engine damage and may decrease corro
-
sion protection. Organic Additive Technology
(OAT) engine coolant is different and should
not be mixed with Hybrid Organic Additive
Technology (HOAT) engine coolant (anti -
freeze) or any “globally compatible” coolant
(antifreeze). If a non-OAT engine coolant
(antifreeze) is introduced into the cooling
system in an emergency, the cooling system
will need to be drained, flushed, and refilled
with fresh OAT coolant (conforming to
MS.90032), by an authorized dealer as soon
as possible.
Do not use water alone or alcohol-based
engine coolant (antifreeze) products. Do not
use additional rust inhibitors or antirust prod -
ucts, as they may not be compatible with the
radiator engine coolant and may plug the
radiator.
Keep hands, tools, clothing, and jewelry
away from the radiator cooling fan when
the hood is raised. The fan starts automati -
cally and may start at any time, whether the
engine is running or not.
When working near the radiator cooling fan,
disconnect the fan motor lead or turn the
ignition to the OFF mode. The fan is
temperature controlled and can start at any
time the ignition is in the ON mode.
WARNING! (Continued)

20_DJD2_OM_EN_USC_t.book Page 412