2023 RAM CHASSIS CAB light

364SERVICING AND MAINTENANCE
NOTE:
A maximum blend of 5% biodiesel, meeting
ASTM specification D-975 may be used with
your Cummins® diesel engine.
A maximum blend of 20% biodiesel, meeting
ASTM specification D-7467 may be used with
your Cummins® diesel engine.
Use of biodiesel mixture in excess of 20% can
negatively impact the fuel filter's ability to sepa -
rate water from the fuel, resulting in high pres -
sure fuel system corrosion or damage.
Ethanol blends are not recommended or
approved for use with your Cummins® diesel
engine.
In addition, commercially available fuel addi -
tives are not necessary for the proper operation
of your Cummins® diesel engine.
INTERVENTION REGENERATION
S
TRATEGY — MESSAGE PROCESS FLOW
The Cummins® diesel engine meets all
Environmental Protection Agency (EPA) Heavy Duty
Diesel Engine Emissions Standards, resulting in
one of the lowest emitting diesel engines ever
produced. To achieve these emissions standards, your
vehicle is equipped with a state-of-the-art engine
and exhaust system. The engine and exhaust
after-treatment system work together to achieve
the EPA Heavy Duty Diesel Engine Emissions
Standards. These systems are seamlessly
integrated into your vehicle and managed by the
Cummins® Powertrain Control Module (PCM). The
PCM manages engine combustion to allow the
exhaust system’s catalyst to trap and burn
Particulate Matter (PM) pollutants, with no input or
interaction on your part.
If the engine is allowed to idle or the truck is driven
on low engine speed drive cycles for more than two
hours, the system will automatically enter an
emissions operating mode that will increase the
engine idle speed to 1,050 RPM. While in this
mode, which is designed to help maintain the
Diesel Particulate Filter, the engine idle speed will
return to normal when the brake pedal is applied.
A small change in engine tone or a slight change in
engine performance while accelerating may also
be noticeable at speeds below 20 mph (32 km/h).
This operating mode may last for up to an hour of
idle time, or around 20 minutes of driving time.
Additionally, your vehicle has the ability to alert you
to additional maintenance required on your truck
or engine Ú
page 89.
DIESEL EXHAUST FLUID (DEF)
DEF sometimes known simply by the name of its
active component, UREA—is a key component of
Selective Catalytic Reduction (SCR) systems, which
help diesel vehicles meet stringent emission
regulations. DEF is a liquid reducing agent that
reacts with engine exhaust in the presence of a
catalyst to convert smog-forming nitrogen oxides
(NOx) into harmless nitrogen and water vapor
Úpage 419.
You can receive assistance in locating DEF by
contacting an authorized dealer.
BODY LUBRICATION
Locks and all body pivot points, including such
items as seat tracks, door hinge pivot points and
rollers, liftgate, tailgate, decklid, sliding doors and
hood hinges, should be lubricated periodically with
a lithium-based grease, such as Mopar® Spray
WARNING!
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.

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SERVICING AND MAINTENANCE371
(Continued)
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 344.
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 Light
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 421.
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 421. Using the wrong type of
brake fluid can severely damage your brake
system and/or impair its performance. 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 an 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 contam -
inate the brake fluid. Brake seal components
could be damaged, causing partial or
complete brake failure. This could result in a
collision.
WARNING!
8

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374SERVICING AND MAINTENANCE
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 with the vehicle
in a level position.
When checking the fluid level, the vehicle should
be in a level position. The fluid level at room
temperature should be as follows:
3500 Front Axle: ¼ inch ± ¼ inch (6.4 mm ±
6.4 mm) below the bottom of the fill hole.
3500 Rear Axle: ¼ inch ± ¼ inch (6.4 mm ±
6.4 mm) below the bottom of the fill hole.
4500/5500 Front Axle: ¼ inch +/- ¼ inch
(6.4 mm ± 6.4 mm) below the bottom of the fill
hole.
4500/5500 Rear Axle: 1/8 inch +/- 1/8 inch (3.2 mm +/- 3.2 mm) below the bottom of the fill
hole.
Drain And Refill
On 4500/5500 vehicles, remove the lower bolt to
drain the axle fluid.
4500/5500 Rear Axle Plugs

For the proper maintenance intervals Úpage 344.
Lubricant Selection
For further information Ú page 421.
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 DO REQUIRE limited slip
oil additive (friction modifiers).
NOTE:Slight noise and mild shuddering may be evident
while turning a vehicle with limited slip differential
on concrete or dry pavement. These conditions
should be considered normal operation of the
limited slip differential.
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 with the vehicle in a level
position.
Drain And Refill
For the proper maintenance intervals Úpage 344.
Selection Of Lubricant
Use only the manufacturer's recommended fluid
Úpage 421.
NOISE CONTROL SYSTEM REQUIRED
M
AINTENANCE & WARRANTY
All vehicles built over 10,000 lb (4,535 kg) Gross
Vehicle Weight Rating and manufactured for sale
and use in the United States are required to
comply with the Federal Government's Exterior
Noise Regulations. These vehicles can be
identified by the Noise Emission Control Label
located in the operator's compartment.
1 — 4500/5500 Rear Axle Fluid Fill Plug
2 — 4500/5500 Rear Axle Fluid Drain Plug

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SERVICING AND MAINTENANCE379
F04 50 Amp Red –400W Inverter
F05 50 Amp Red –Air Suspension Comp
F06 40 Amp Green –STOM
F07 40 Amp Green –Starter Solenoid
F08 20 Amp Blue –NOX Sensor *
F09 30 Amp Pink
–Gas – Brake Vacuum Pump *
40 Amp Green Diesel – Fuel Heater *
F10 40 Amp Green –CBC #2 / Ext Lights
F11 40 Amp Green –Brake SYS MOD ECU & Valves
F12 40 Amp Green –CBC #3 / Pwr Locks
F13 40 Amp Green –HVAC Blwr Mtr
F14 40 Amp Green –CBC #4 / Ext Light
F15 30 Amp Pink –Power Side Step *
F16 30 Amp Pink –Smart - Bar Module *
F17 30 Amp Pink –Winch *
F18 ––Spare
F19 30 Amp Pink –Diesel SCR Feed *
F20 30 Amp Pink –Passenger Door Mod
F21 30 Amp Pink –DTCM
Cavity Cartridge Fuse Micro FuseDescription
* If Equipped
8

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380SERVICING AND MAINTENANCE
F22 20 Amp Blue
–Gas – ECM *
25 Amp White Diesel – PCM *
F23 30 Amp Pink –CBC #1 / Int Light
F24 30 Amp Pink –Driver Door Mod
F25 30 Amp Pink –FT Wiper
F26 ––Spare
F27 ––Spare
F28 20 Amp Blue –TRLR Tow B / U
F29 20 Amp Blue –TRLR TOW PARK
F30 30 Amp Pink –TRLR Tow
F31 ––Spare
F32 ––Spare
F33 20 Amp Blue –Trans Control Mod *
F34 30 Amp Pink –VSIM #2 *
F35 30 Amp Pink –Sunroof *
F36 30 Amp Pink –Rear Defroster (EBL) *
F37 30 Amp Pink –Diesel Frame / Fuel HTR *
F38 30 Amp Pink –ITBM *
F39 ––Spare
F40 –10 Amp RedVented Seats *
Cavity Cartridge Fuse Micro FuseDescription
* If Equipped

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SERVICING AND MAINTENANCE381
F41 –10 Amp RedAct Grille Shutter / Dam *
F42 –20 Amp YellowHorn
F43 –15 Amp BlueHeated Strng Wheel *
F44 –10 Amp RedDiagnostic Port
F45 ––Spare
F46 –10 Amp RedUpfitters Relay Coils *
F47 ––Spare
F48 ––Spare
F49 –15 Amp BlueIP Cluster / CSG
F50 –20 Amp YellowAir Suspension Mod *
F51 –10 Amp RedIGN Mod / KINMod / RFHub
F52 –5 Amp TanBatt Snsr
F53 –20 Amp YellowTrlr Tow – Lt Turn/Stop
F54 –20 Amp YellowNon-Memory Adj Pedals *
F55 –10 Amp RedFwd Utility Lamps
F56 –10 Amp RedVBV
F57 –20 Amp YellowTCM / PCM / Trans PRSR SW
F58 –10 Amp RedBed Lighting
F59 ––Spare
F60 ––Spare
Cavity Cartridge Fuse Micro FuseDescription
* If Equipped
8

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384SERVICING AND MAINTENANCE
BULB REPLACEMENT
Replacement Bulbs, Names, And Part Numbers
In the instance a bulb needs to be replaced, this section includes bulb description and replacement part numbers.
NOTE:See an authorized dealer for LED bulb replacement.F99
–10 Amp RedHVAC / IN-CARTS / CSG / TRL CWY
MOD */ TACH
F100 –10 Amp RedUpfitter Box Feed *
F101 –20 Amp YellowRR HTD ST Right *
F102 –20 Amp YellowRR HTD ST Left / Run RLY #3 *
F103 –10 Amp RedHeadLamp AFLS *
F104 –20 Amp YellowUCI Port / USB Rear
Cavity Cartridge Fuse Micro FuseDescription
* If Equipped
Interior Bulbs
Bulb Name Bulb Number
Overhead Console Lamps TS 212–9
Dome Lamp 7679
NOTE:For lighted switches, see an authorized dealer for replacement instructions.

23_DPF_OM_EN_USC_t.book Page 384

SERVICING AND MAINTENANCE389

Removing Bulb Socket From Clearance Lamp

3. Pull the bulb straight from it's socket and replace.
TIRES
TIRE SAFETY INFORMATION
Tire safety information will cover aspects of the
following information: Tire Markings, Tire
Identification Numbers, Tire Terminology and
Definitions, Tire Pressures, and Tire Loading.
Tire Markings

Tire Markings

NOTE:
P (Passenger) — Metric tire sizing is based on US
design standards. P-Metric tires have the letter
“P” molded into the sidewall preceding the size
designation. Example: P215/65R15 95H.
European — Metric tire sizing is based on Euro -
pean design standards. Tires designed to this
standard have the tire size molded into the side -
wall beginning with the section width. The letter
"P" is absent from this tire size designation.
Example: 215/65R15 96H.
LT (Light Truck) — Metric tire sizing is based on
US design standards. The size designation for
LT-Metric tires is the same as for P-Metric tires
except for the letters “LT” that are molded into
the sidewall preceding the size designation.
Example: LT235/85R16.
Temporary spare tires are designed for tempo -
rary emergency use only. Temporary high pres -
sure compact spare tires have the letter “T” or
“S” molded into the sidewall preceding the size
designation. Example: T145/80D18 103M.
High flotation tire sizing is based on US design
standards and it begins with the tire diameter
molded into the sidewall. Example: 31x10.5
R15 LT.
1 — US DOT Safety Standards Code
(TIN)
2 — Size Designation
3 — Service Description
4 — Maximum Load
5 — Maximum Pressure
6 — Treadwear, Traction and
Temperature Grades
8

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