engine RAM CHASSIS CAB 2021 Owners Manual

386SERVICING AND MAINTENANCE
Checking Coolant Level — 6.4L 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.

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 (antifreeze) 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

The charge air cooler is positioned below 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 and
through another hose to the intake manifold of
the engine. The air entering the engine has been
cooled by about 50° to 100°F (10° to 38°C).
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.

21_DPF_OM_EN_USC_t.book Page 386

SERVICING AND MAINTENANCE387
(Continued)
BRAKE SYSTEM
In order to ensure brake system performance,
all brake system components should be
inspected periodically Ú page 354.
Fluid Level Check — Brake Master Cylinder
The fluid level of the master cylinder should be
checked when performing under the hood
service or immediately if the brake system
warning lamp indicates system failure.

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 the fluid level can be expected
to fall as the brake linings wear. However, an
unexpected drop in fluid level may be caused by
a leak and a system check should be conducted.

For further information Ú
page 444.
AUTOMATIC TRANSMISSION
Special Additives

The manufacturer 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.
The only exception to this policy is the use of special
dyes for diagnosing fluid leaks in six-speed
transmissions. Avoid using transmission sealers as
they may adversely affect seals.

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 Úpage 444. 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 reservoir 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)
8

21_DPF_OM_EN_USC_t.book Page 387

388SERVICING AND MAINTENANCE
Fluid Level Check — Eight-Speed
Transmission
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 Level Check — Six-Speed
Transmission
It is best to check the fluid level when the
transmission is at normal operating
temperature (158-176°F / 70-80°C). This
normally occurs after at least 15 miles (25 km)
of driving. At normal operating temperature the
fluid cannot be held comfortably between the
fingertips. You can read the transmission sump
temperature in the instrument cluster screen
Ú page 90. Use the following procedure to check the
transmission fluid level properly:

1. Monitor the transmission temperature
using the instrument cluster display, and
operate the vehicle as required to reach
the normal operating temperature. If the
transmission is not functioning properly, or
the vehicle cannot be driven, see the NOTE
and CAUTION below about checking the
fluid level at colder temperatures.

2. Park the vehicle on level ground.
3. Run the engine at normal idle speed for at least 60 seconds, and leave the engine
running for the rest of this procedure.
4. Fully apply the parking brake, and press the brake pedal.
5. Place the gear selector momentarily into each gear position (allowing time for the
transmission to fully engage in each
position), ending with the transmission in
PARK.
6. Remove the dipstick, wipe it clean and reinsert it until seated.
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.

21_DPF_OM_EN_USC_t.book Page 388

SERVICING AND MAINTENANCE389
7. Remove the dipstick again and note the
fluid level on both sides. The fluid level
reading is only valid if there is a solid
coating of oil on both sides of the dipstick.
Note that the holes in the dipstick will be full
of fluid if the actual level is at or above the
hole. The fluid level should be between the
“HOT” (upper) reference holes on the
dipstick at normal operating temperature.
If the fluid level is low, add fluid through the
dipstick tube to bring it to the proper level.
Do not overfill. Use ONLY the specified fluid
Ú page 444. After adding any quantity of oil
through the dipstick tube, wait a minimum
of two minutes for the oil to fully drain into
the transmission before rechecking the
fluid level.
NOTE:

If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two “COLD” (lower) holes on the
dipstick with the fluid at 60-70°F / 16-21°C. Only
use the COLD region of the dipstick as a rough refer -
ence when setting the fluid level after a transmis -sion service or fluid change. Re-check the fluid level,
and adjust as required, once the transmission
reaches normal operating temperature.

8. Reinsert the dipstick. Check for leaks.
Release the parking brake.
NOTE:

If it is necessary to check the transmission below
the operating temperature, the fluid level should be
between the two COLD (lower) holes on the dipstick
with the fluid at 68-86°F / 20-30°C. Only use the
COLD region of the dipstick as a rough reference
when setting the fluid level after a transmission
service or fluid change. Re-check the fluid level, and
adjust as required, once the transmission reaches
normal operating temperature.

Fluid And Filter Changes — Eight-Speed
Transmission
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.

Fluid And Filter Changes — Six Speed
Transmission
For the proper maintenance intervals
Ú page 354.
In addition, change the fluid and filters if the
fluid becomes contaminated (with water, etc.),
or if the transmission is disassembled for any
reason.
CAUTION!
If the fluid temperature is below 50°F (10°C)
it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough
to produce an accurate reading. Run the
engine at idle, in PARK, to warm the fluid.
CAUTION!
If the fluid temperature is below 50°F (10°C)
it may not register on the dipstick. Do not add
fluid until the temperature is elevated enough
to produce an accurate reading. Run the
engine at idle, in PARK, to warm the fluid.
8

21_DPF_OM_EN_USC_t.book Page 389

392SERVICING AND MAINTENANCE
Air Cleaner Assembly
Inspect air cleaner housing for proper assembly
and fit. Make certain that the air cleaner is
properly positioned and that the cover is tight.
Check all hoses leading to the air cleaner for
tightness. The air filter element must also be
clean and serviced according to the instructions
outlined in the Scheduled Maintenance section
of this manual.
Tampering With Noise Control System
Prohibited

Federal law prohibits the following acts or the
causing thereof: (1) the removal or rendering
inoperative by any person, other than for purposes
of maintenance, repair, or replacement, of any
device or element of design incorporated into any
new vehicle for the purpose of noise control prior to
its sale or delivery to the ultimate purchaser or while
it is in use, or (2) the use of the vehicle after such
device or element of design has been removed or
rendered inoperative by any person.

Among those acts presumed to constitute
tampering are the acts listed below. AIR CLEANER

Removal of the air cleaner.
Removal of the air cleaner filter element from
the air cleaner housing.
Removal of the air ducting.
EXHAUST SYSTEM
Removal or rendering inoperative exhaust
system components including the muffler or
tailpipe.
ENGINE COOLING SYSTEM
Removal or rendering inoperative the fan
clutch.
Removal of the fan shroud.
Noise Emission Warranty
The manufacturer warrants that this vehicle as
manufactured by the manufacturer, was
designed, built and equipped to conform at the
time it left the manufacturer's control with all
applicable U.S. EPA Noise Control Regulations.
This warranty covers this vehicle as designed,
built and equipped by the manufacturer, and is
not limited to any particular part, component or
system of the vehicle manufactured by the
manufacturer. Defects in design, assembly or in
any part, component or system of the vehicle as
manufactured by the manufacturer, which, at
the time it left the manufacturer's control,
caused noise emissions to exceed Federal
standards, are covered by this warranty for the
life of the vehicle.

21_DPF_OM_EN_USC_t.book Page 392

SERVICING AND MAINTENANCE393
Maintenance Log and Service Chart (Diesel Engines)
Noise Systems Maintenance Chart and Service Log — Insert Month, Day, Year under column mileage closest to the mileage at which
service was performed.
MILES7,500 15,000 22,500 30,000 37,500 45,000 52,500 60,000
KILOMETERS 12,000 24 ,000 36,000 48,000 60,000 72,000 84,000 96,000

Exhaust
system-inspect
Air cleaner
assembly-inspect
ODOMETER
READING
PERFORMED BY
PERFORMED AT

MILES 67,500 75,000 82,500 90,000 97,500 105,000 112,500 120,000
KILOMETERS 108,000 120,000 132,000 144,000 156,000 168,000 180,000 192,000
Exhaust
system-inspect
Air cleaner
assembly-inspect
ODOMETER
READING
8

21_DPF_OM_EN_USC_t.book Page 393

394SERVICING AND MAINTENANCE
(Continued)
FUSES
General Information 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

PERFORMED BY
PERFORMED AT
Noise Systems Maintenance Chart and Service Log — Insert Month, Day, Year under column mileage closest to the mileage at which
service was performed.
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.
WARNING! (Continued)
1 — Fuse Element
2 — Blade Fuse with a good/functional fuse
element
3 — Blade fuse with a bad/not functional fuse
element (blown fuse)

21_DPF_OM_EN_USC_t.book Page 394

SERVICING AND MAINTENANCE395
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 Location

Cavity Cartridge FuseMicro Fuse Description
F01– –Spare
F02 60 Amp Yellow –ABS Pump Motor (HD Only)
F03 60 Amp Yellow –Rad Fan – If Equipped
F04 50 Amp Red 400W Inverter – If Equipped
F05 40 Amp Green –Compressor For Air Suspension – If Equipped
F06 40 Amp Green –Steering Torque Overlay Module (STOM)
F07 40 Amp Green –Starter Solenoid
F08 20 Amp Blue –NOX Sensor – If Equipped
F09 40 Amp Green –Diesel / Fuel Heater – If Equipped
F09 30 Amp Pink –Gas / Brake Vacuum Pump – If Equipped
F10 40 Amp Green –CBC #2 / Ext Lights
F11 40 Amp Green –Brake System Module (ECU and Valves)
8

21_DPF_OM_EN_USC_t.book Page 395

SERVICING AND MAINTENANCE399
F74–10 Amp Red Backup Alarm – If Equipped
F75 –10 Amp Red ATMM / Coil-SCR Module RLY – If Equipped
F76 –10 Amp Red Electronic Stability Control — If Equipped
F77 –10 Amp Red Drivetrain Control Module / Front Axle Disconnect Module / TCM/ STOM
F78 –15 Amp BlueEngine Control Module / Powertrain Control Module / AEB RACM MOD /
Feed To AUX PDC Relay Coils/ HRLS
F79 –15 Amp Blue ID / Clearance Lights
F80 –10 Amp Red Overhead Console / Assist / 911 – If Equipped
F81 –20 Amp Yellow Trailer Tow Right Turn / Stop Lights - If Equipped
F82 –10 Amp Red Steering Column Control Module / Cruise Control
F83 – –Spare
F84 –15 Amp Blue ASBM / HVAC / ICS / Rear Heated Seat Switches
F85 –10 Amp Red Airbag Module
F86 –10 Amp Red Airbag Module
F87 –10 Amp RedAir Suspension / ITBM / Steering Column Control Module / MOD Gateway
CAN-C Trailer TPM
F88 –15 Amp Blue Instrument Panel Cluster
F90/F91 –20 Amp Yellow Power Outlet / Batt
Power Outlet / Acc
F92 – –Spare
F93 – –Spare
Cavity Cartridge Fuse Micro Fuse Description
8

21_DPF_OM_EN_USC_t.book Page 399

431
TECHNICAL SPECIFICATIONS
VEHICLE IDENTIFICATION NUMBER (VIN)
The VIN is found on the left front corner of
the instrument panel, visible through the
windshield.
Vehicle Identification Number

NOTE:
It is illegal to remove or alter the VIN.
BRAKE SYSTEM
If power assist is lost for any reason (for
example, repeated brake applications with
the engine off), the brakes will still function.
However, you will experience a substantial
increase in braking effort to stop the vehicle.

If either the front or rear hydraulic system loses
normal braking capability, the remaining system
will still function with some loss of overall braking
effectiveness. This will be evident by increased
pedal travel during application, greater pedal
force required to slow or stop, and activation of
the “Brake Warning Light” and/or the “ABS
Warning Light” during brake use.

HYDRAULIC BRAKE ASSIST — IF
E
QUIPPED
The brake system power assist is provided by a
hydro-boost unit which shares fluid with the
power steering system. You may experience
some clicking or hissing noises from the
hydro-boost system during hard braking
conditions.
NOTE:
Under cold temperatures, pedal effort will be
higher than normal until the power steering fluid
reaches operating temperature.
9

21_DPF_OM_EN_USC_t.book Page 431