2021 RAM 1500 Owners Manual

SERVICING AND MAINTENANCE423
NOTE:
It is the owner's responsibility to maintain the
proper level of protection against freezing
according to the temperatures occurring in
the area where the vehicle is operated.
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.
Mixing engine coolant types is not recom -
mended and can result in cooling system
damage. If HOAT and OAT coolant are mixed
in an emergency, have an authorized dealer
drain, flush, and refill with OAT coolant
(conforming to MS.90032) as soon as
possible.
Cooling System Pressure Cap
The cap must be fully tightened to prevent loss
of engine coolant (antifreeze), and to ensure
that engine coolant will return to the radiator
from the coolant expansion bottle/recovery
tank (if equipped). The cap should be inspected and cleaned if
there is any accumulation of foreign material on
the sealing surfaces.
Disposal Of Used Coolant
Used ethylene glycol-based coolant (antifreeze)
is a regulated substance requiring proper
disposal. Check with your local authorities to
determine the disposal rules for your
community. To prevent ingestion by animals or
children, do not store ethylene glycol-based
coolant in open containers or allow it to remain
in puddles on the ground, clean up any ground
spills immediately. If ingested, seek emergency
assistance immediately.
Checking Coolant Level — 3.6L Engine
The level of the coolant in the pressurized
coolant bottle should be between the “MIN” and
“MAX” range on the bottle when the engine is
cold.
The radiator normally remains completely full,
so there is no need to remove the cap unless
checking for coolant freeze point or replacing
engine coolant (antifreeze). Advise your service
attendant of this. As long as the engine
operating temperature is satisfactory, the
coolant bottle need only be checked once a
month. When additional engine coolant is
needed to maintain the proper level, it should
be added to the coolant bottle. Do not overfill.
Checking Coolant Level — 5.7L Engines
With the engine off and cold, the level of the
engine coolant should be between the ADD and
SAFE range on the dipstick.
To check the coolant level:

1. Open the coolant reservoir.

2. Lift and remove the plastic dipstick from the
reservoir neck.
WARNING!
Do not open hot engine cooling system.
Never add engine coolant (antifreeze) when
the engine is overheated. Do not loosen or
remove the cap to cool an overheated
engine. Heat causes pressure to build up in
the cooling system. To prevent scalding or
injury, do not remove the pressure cap
while the system is hot or under pressure.
Do not use a pressure cap other than the
one specified for your vehicle. Personal
injury or engine damage may result.
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424SERVICING AND MAINTENANCE

Coolant Reservoir Dipstick

3. Check the coolant level on the dipstick.
The radiator normally remains completely full,
so there is no need to remove the radiator cap
unless checking for engine coolant (antifreeze)
freeze point or replacing engine coolant. Advise
your service attendant of this. As long as the
engine operating temperature is satisfactory,
the coolant bottle need only be checked once a
month.
When additional engine coolant is needed to
maintain the proper level, it should be added to
the coolant bottle. Do not overfill.
Cooling System Notes
NOTE:
When the vehicle is stopped after a few miles/
kilometers of operation, you may observe vapor
coming from the front of the engine compart -
ment. This is normally a result of moisture from
rain, snow, or high humidity accumulating on
the radiator and being vaporized when the ther -
mostat opens, allowing hot engine coolant (anti -
freeze) to enter the radiator.
If an examination of your engine compartment
shows no evidence of radiator or hose leaks,
the vehicle may be safely driven. The vapor will
soon dissipate.
Do not overfill the coolant expansion bottle.
Check the coolant freeze point in the radiator
and in the coolant expansion bottle. If engine
coolant needs to be added, the contents of
the coolant expansion bottle must also be
protected against freezing.
If frequent engine coolant additions are
required, the cooling system should be pres -
sure tested for leaks.
Maintain engine coolant concentration at a
minimum of 50% OAT coolant (conforming to
MS.90032) and distilled water for proper
corrosion protection of your engine which
contains aluminum components.
Make sure that the coolant expansion bottle
overflow hoses are not kinked or obstructed.
Keep the front of the radiator clean. If your
vehicle is equipped with air conditioning,
keep the front of the condenser clean.
Do not change the thermostat for Summer or
Winter operation. If replacement is ever
necessary, install ONLY the correct type ther -
mostat. Other designs may result in unsatis -
factory engine cooling performance, poor gas
mileage, and increased emissions.
CHARGE AIR COOLER — INTER-COOLER
(D
IESEL ENGINE)
The charge air cooler is positioned in front of the
radiator and the air conditioner condenser. Air
enters the engine through the air cleaner and
passes through the turbocharger, where it is
pressurized. This pressurized air rapidly
reaches high temperature. The air is then
directed through a hose to the charge air cooler

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SERVICING AND MAINTENANCE425
(Continued)
and through another hose to the intake
manifold of the engine. This cooling process
enables more efficient burning of fuel resulting
in fewer emissions.
To guarantee optimum performance of the
system, keep the surfaces of the charge air
cooler, condenser and radiator clean and free
of debris. Periodically check the hoses leading
to and from the charge air cooler for cracks or
loose clamps resulting in loss of pressure and
reduced engine performance.
BRAKE SYSTEM
In order to ensure brake system performance,
all brake system components should be
inspected periodically Ú page 395.
Fluid Level Check — Brake Master Cylinder
The fluid level of the brake master cylinder
should be checked whenever the vehicle is
serviced, or immediately if the brake system
warning light is on. If necessary, add fluid to
bring level within the designated marks on the
side of the reservoir of the brake master
cylinder. Be sure to clean the top of the master
cylinder area before removing cap. With disc
brakes, fluid level can be expected to fall as the
brake pads wear. Brake fluid level should be
checked when pads are replaced. If the brake
fluid is abnormally low, check the system for
leaks Úpage 478.
WARNING!
Riding the brakes can lead to brake failure
and possibly a collision. Driving with your foot
resting or riding on the brake pedal can result
in abnormally high brake temperatures,
excessive lining wear, and possible brake
damage. You would not have your full braking
capacity in an emergency.
WARNING!
Use only manufacturer's recommended
brake fluid Ú page 478. Using the wrong
type of brake fluid can severely damage
your brake system and/or impair its perfor -
mance. The proper type of brake fluid for
your vehicle is also identified on the original
factory installed hydraulic master cylinder
reservoir.
To avoid contamination from foreign matter
or moisture, use only new brake fluid or
fluid that has been in a tightly closed
container. Keep the master cylinder reser -
voir cap secured at all times. Brake fluid in
a open container absorbs moisture from
the air resulting in a lower boiling point. This
may cause it to boil unexpectedly during
hard or prolonged braking, resulting in
sudden brake failure. This could result in a
collision.
Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine
parts, causing the brake fluid to catch fire.
Brake fluid can also damage painted and
vinyl surfaces, care should be taken to
avoid its contact with these surfaces.
Do not allow petroleum based fluid to
contaminate the brake fluid. Brake seal
components could be damaged, causing
partial or complete brake failure. This could
result in a collision.
WARNING! (Continued)
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426SERVICING AND MAINTENANCE
AUTOMATIC TRANSMISSION
Special Additives
FCA strongly recommends against using any
special additives in the transmission. Automatic
Transmission Fluid (ATF) is an engineered
product and its performance may be impaired
by supplemental additives. Therefore, do not
add any fluid additives to the transmission.
Avoid using transmission sealers as they may
adversely affect seals.
Fluid Level Check
The fluid level is preset at the factory and does
not require adjustment under normal operating
conditions. Routine fluid level checks are not
required, therefore the transmission has no
dipstick. An authorized dealer can check your
transmission fluid level using special service
tools. If you notice fluid leakage or transmission
malfunction, visit an authorized dealer
immediately to have the transmission fluid level
checked. Operating the vehicle with an
improper fluid level can cause severe
transmission damage.
Fluid And Filter Changes
Under normal operating conditions, the fluid
installed at the factory will provide satisfactory
lubrication for the life of the vehicle.
Routine fluid and filter changes are not
required. However, change the fluid and filter if
the fluid becomes contaminated (with water,
etc.), or if the transmission is disassembled for
any reason.
Selection Of Lubricant
It is important to use the proper transmission
fluid to ensure optimum transmission performance and life. Use only the
recommended transmission fluid
Úpage 478.
It is important to maintain the transmission fluid
at the correct level using the recommended
fluid. No chemical flushes should be used in any
transmission; only the approved lubricant
should be used.
REAR AXLE AND 4X4 FRONT DRIVING
A
XLE FLUID LEVEL
For normal service, periodic fluid level checks
are not required. When the vehicle is serviced
for other reasons the exterior surfaces of the
axle assembly should be inspected. If gear oil
leakage is suspected inspect the fluid level
Ú page 478. This inspection should be made
with the vehicle in a level position.
The fluid level should be even with the bottom
of the fill hole (within 1/4 in (6.4 mm) of edge of
hole) for the front axle and rear axle.
CAUTION!
Do not use chemical flushes in your
transmission as the chemicals can damage
your transmission components. Such damage
is not covered by the New Vehicle Limited
Warranty.
CAUTION!
If a transmission fluid leak occurs, visit an
authorized dealer immediately. Severe
transmission damage may occur. An
authorized dealer has the proper tools to
adjust the fluid level accurately.CAUTION!
Using a transmission fluid other than the
manufacturer’s recommended fluid may
cause deterioration in transmission shift
quality and/or torque converter shudder
Ú page 478.

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SERVICING AND MAINTENANCE427
Drain And Refill
For the proper maintenance intervals
Úpage 395.
Lubricant Selection
For further information Ú page 478.
NOTE:
The presence of water in the gear lubricant will
result in corrosion and possible failure of differ -
ential components. Operation of the vehicle in
water, as may be encountered in some
off-highway types of service, will require
draining and refilling the axle to avoid damage.
Limited-Slip Differentials
Rear axles equipped with a Limited Slip
Differential require that 5 oz. (148 ml) Mopar
Limited Slip Additive be added to the gear
lubricant Ú page 478. The Mopar Limited Slip
Additive should be added to the gear lubricant
whenever a fluid change is made to an axle
equipped with a Limited Slip Differential. NOTE:
When refilling a limited slip differential axle
which requires a friction modification additive,
the additive should be added before the gear
lubricant to ensure proper additive fill.TRANSFER CASE
Fluid Level Check
This fluid level can be checked by removing the
filler plug. The fluid level should be to the
bottom edge of the filler plug hole (or within
1/8 inch of the bottom) with the vehicle in a
level position.
Drain And Refill
For the proper maintenance intervals
Ú
page 395.
Selection Of Lubricant
Use only the recommended fluid Ú page 478.
FUSES
General Information
WARNING!
When replacing a blown fuse, always use
an appropriate replacement fuse with the
same amp rating as the original fuse. Never
replace a fuse with another fuse of higher
amp rating. Never replace a blown fuse with
metal wires or any other material. Do not
place a fuse inside a circuit breaker cavity
or vice versa. Failure to use proper fuses
may result in serious personal injury, fire
and/or property damage.
Before replacing a fuse, make sure that the
ignition is off and that all the other services
are switched off and/or disengaged.
If the replaced fuse blows again, contact an
authorized dealer.
If a general protection fuse for safety
systems (air bag system, braking system),
power unit systems (engine system, trans -
mission system) or steering system blows,
contact an authorized dealer.
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428SERVICING AND MAINTENANCE
The fuses protect electrical systems against
excessive current.
When a device does not work, you must check
the fuse element inside the blade fuse for a
break/melt.
Also, please be aware that when using power
outlets for extended periods of time with the
engine off may result in vehicle battery
discharge.
Blade Fuses

External Power Distribution Center
The Power Distribution Center is located in the
engine compartment near the battery. This
center contains cartridge fuses, micro fuses,
relays, and circuit breakers. A description of
each fuse and component may be stamped on
the inside cover, otherwise the cavity number of
each fuse is stamped on the inside cover that
corresponds to the following chart.

Power Distribution Center
CAUTION!
If it is necessary to wash the engine
compartment, take care not to directly hit the
fuse box, and the windshield wiper motors
with water.
1 — Fuse Element
2 — Blade Fuse with a good/functional fuse ele -
ment
3 — Blade fuse with a bad/not functional fuse el -
ement (blown fuse)
Cavity Cartridge Fuse Micro Fuse Description
F01–25 Amp Clear Fuel Pump Motor
F03 –5 Amp Tan MGU
F04 ––Spare
F05 ––Spare

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SERVICING AND MAINTENANCE429
F06–10 Amp Red OUTPUT TO UPFITTER PDC — If Equipped
F07 ––Spare
F08 20 Amp Blue –Trailer Tow Backup
F09 –20 Amp Yellow Trailer Stop / Turn Lamp Left
F10 –20 Amp Yellow Trailer Stop / Turn Lamp Right
F11 –15 Amp Blue ID/CLEARANCE LIGHTS — If Equipped
F12 20 Amp Blue –Trailer Tow Park Lamp
F13 ––Spare
F14 –10 Amp Red AC Clutch
F15 –5 Amp Tan Intelligent Battery Sensor (IBS)
F16 ––Spare
F17 –20 Amp Yellow Air Suspension
F18 –15 Amp Blue AGS / Rear Axle Cooling Valve / Active Air Dam
F19 ––Spare
F20 –20 Amp Yellow Adjustable Pedals
F21 30 Amp Pink –Power Side Step
F22 50 Amp Red –Air Module
F23 ––Spare
F24 –20 Amp Yellow TCM SBW
F25 40 Amp Green –Exterior Lights 2
Cavity Cartridge Fuse Micro Fuse Description
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430SERVICING AND MAINTENANCE
F2650 Amp Red –ESP Module
F27 30 Amp Pink –Front Wiper
F28 –10 Amp Red PCM / ECM
F29 40 Amp Green –ESP Module
F30 ––Spare
F31 ––Spare
F32 20 Amp Blue –ECM / PCM
F33 30 Amp Pink –Brake Vacuum Pump
F34 ––Spare
F35 –10 Amp RedPCM / ECM / Power Pack Unit (PPU) Motor Generator Unit (MGU)
Wake Up / EPS / Active Tuned Mass Module (ATMM) / ESP
F36 ––Spare
F37 –5 Amp Tan R / S Output to iPDC
F38 –10 Amp Red DTCM / Active CL TEMP VLV
F39 –15 Amp Red MOD ATMM
F40 40 Amp Green –Starter
F41 –10 Amp Red IRCAM Heaters
F42 20 Amp Blue –AUX SWITCH #5 — If Equipped
F43 –20 Amp Yellow MGU Coolant Pump
F44 –10 Amp Red Trailer Camera
F45 –10 Amp Red ADCM — If Equipped
CavityCartridge Fuse Micro Fuse Description

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