2020 Ram 4500 Chassis Cab Service

GETTING TO KNOW YOUR INSTRUMENT PANEL111
If the light continues to flash when the vehicle is
running, immediate service is required and you
may experience reduced performance, an
elevated/rough idle, or engine stall and your
vehicle may require towing. The light will come
on when the ignition is placed in the ON/RUN or
ACC/ON/RUN position and remain on briefly as
a bulb check. If the light does not come on
during starting, have the system checked by an
authorized dealer.
Electric Power Steering Fault Warning Light
This warning light will turn on when
there's a fault with the Electric Power
Steering (EPS) system. Refer to
“Power Steering” in “Starting And
Operating” for further information.
Trailer Brake Disconnected Warning Light
This warning light will illuminate when
the Trailer Brake has been discon -
nected.
Refer to “Trailer Towing” in “Starting And Oper -
ating” for further information.
Transmission Temperature Warning Light — If
Equipped
This warning light will illuminate to
warn of a high transmission fluid
temperature. This may occur with
strenuous usage such as trailer
towing. If this light turns on, stop the vehicle and
run the engine at idle or slightly faster, with the
transmission in PARK or NEUTRAL, until the
light turns off. Once the light turns off, you may
continue to drive normally.
Door Open Warning Light
This indicator will illuminate when a
door is ajar/open and not fully closed.
NOTE:
If the vehicle is moving there will also be a single
chime.
Yellow Warning Lights
Adaptive Cruise Control (ACC) Fault Warning
Light — If Equipped
This warning light will illuminate to
indicate a fault in the ACC system.
Contact a local authorized dealer for
service.
For further information, refer to “Adaptive
Cruise Control (ACC)” in “Starting And Oper -
ating.”
WARNING!
Continued operation with reduced assist
could pose a safety risk to yourself and
others. Service should be obtained as soon
as possible.WARNING!
If you continue operating the vehicle when
the Transmission Temperature Warning Light
is illuminated you could cause the fluid to boil
over, come in contact with hot engine or
exhaust components and cause a fire.
CAUTION!
Continuous driving with the Transmission
Temperature Warning Light illuminated will
eventually cause severe transmission
damage or transmission failure.
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112GETTING TO KNOW YOUR INSTRUMENT PANEL
Engine Check/Malfunction Indicator Warning
Light (MIL)
The Engine Check/Malfunction Indi-
cator Light (MIL) is a part of an
Onboard Diagnostic System called
OBD II that monitors engine and auto -
matic transmission control systems. This
warning light will illuminate when the ignition is
in the ON/RUN position before engine start. If
the bulb does not come on when turning the
ignition switch from OFF to ON/RUN, have the
condition checked promptly.
Certain conditions, such as a loose or missing
gas cap, poor quality fuel, etc., may illuminate
the light after engine start. The vehicle should
be serviced if the light stays on through several
typical driving styles. In most situations, the
vehicle will drive normally and will not require
towing.
When the engine is running, the MIL may flash
to alert serious conditions that could lead to
immediate loss of power or severe catalytic
converter damage. The vehicle should be
serviced by an authorized dealer as soon as
possible if this occurs.
Electronic Stability Control (ESC) Active
Warning Light — If Equipped
This warning light will indicate when
the Electronic Stability Control system
is Active. The “ESC Indicator Light” in
the instrument cluster will come on
when the ignition is placed in the ON/RUN or
ACC/ON/RUN position, and when ESC is acti -vated. It should go out with the engine running.
If the “ESC Indicator Light” comes on continu
-
ously with the engine running, a malfunction
has been detected in the ESC system. If this
warning light remains on after several ignition
cycles, and the vehicle has been driven several
miles (kilometers) at speeds greater than
30 mph (48 km/h), see an authorized dealer as
soon as possible to have the problem diag -
nosed and corrected.
The “ESC OFF Indicator Light” and the “ESC
Indicator Light” come on momentarily each
time the ignition is placed in the ON/RUN or
ACC/ON/RUN position.
The ESC system will make buzzing or clicking
sounds when it is active. This is normal; the
sounds will stop when ESC becomes inactive.
This light will come on when the vehicle is in
an ESC event.
Electronic Stability Control (ESC) OFF
Warning Light — If Equipped
This warning light indicates the Elec -
tronic Stability Control (ESC) is off.
Each time the ignition is turned to ON/
RUN or ACC/ON/RUN, the ESC system
will be on, even if it was turned off previously.
WARNING!
A malfunctioning catalytic converter, as
referenced above, can reach higher
temperatures than in normal operating
conditions. This can cause a fire if you drive
slowly or park over flammable substances
such as dry plants, wood, cardboard, etc. This
could result in death or serious injury to the
driver, occupants or others.
CAUTION!
Prolonged driving with the Malfunction
Indicator Light (MIL) on could cause damage
to the vehicle control system. It also could
affect fuel economy and driveability. If the
MIL is flashing, severe catalytic converter
damage and power loss will soon occur.
Immediate service is required.

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GETTING TO KNOW YOUR INSTRUMENT PANEL113
Low Washer Fluid Warning Light — If
Equipped
This warning light will illuminate when
the windshield washer fluid is low.
Refer to “Engine Compartment” in “Servicing
And Maintenance” for further information.
Low Fuel Warning Light
When the fuel level reaches approxi -
mately 3.2 gal (12 L) this light will turn
on, and remain on until fuel is added.
A single warning chime will sound with Low Fuel
Warning.
Low Coolant Level Warning Light
This telltale will turn on to indicate the
vehicle coolant level is low.
Refer to “Dealer Service” in “Servicing And
Maintenance” for further information.
Loose Fuel Filler Cap Warning Light — If
Equipped
This warning light will illuminate when
the fuel filler cap is loose. Properly
close the filler cap to disengage the light. If the light does not turn off, please see an
authorized dealer.
Tire Pressure Monitoring System (TPMS)
Warning Light — If Equipped
The warning light switches on and a
message is displayed to indicate that
the tire pressure is lower than the
recommended value and/or that slow
pressure loss is occurring. In these cases,
optimal tire duration and fuel consumption may
not be guaranteed.
Should one or more tires be in the condition
mentioned above, the display will show the indi -
cations corresponding to each tire.
Each tire, including the spare (if provided),
should be checked monthly when cold and
inflated to the inflation pressure recommended by the vehicle manufacturer on the vehicle
placard or tire inflation pressure label. If your
vehicle has tires of a different size than the size
indicated on the vehicle placard or tire inflation
pressure label, you should determine the
proper tire inflation pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a Tire Pressure Monitoring
System (TPMS) that illuminates a low tire pres
-
sure telltale when one or more of your tires is
significantly under-inflated. Accordingly, when
the low tire pressure telltale illuminates, you
should stop and check your tires as soon as
possible, and inflate them to the proper pres -
sure. Driving on a significantly under-inflated
tire causes the tire to overheat and can lead to
tire failure. Under-inflation also reduces fuel
efficiency and tire tread life, and may affect the
vehicle’s handling and stopping ability.
Please note that the TPMS is not a substitute for
proper tire maintenance, and it is the driver’s
responsibility to maintain correct tire pressure,
even if under-inflation has not reached the level
to trigger illumination of the TPMS low tire pres -
sure telltale.
CAUTION!
Do not continue driving with one or more flat
tires as handling may be compromised. Stop
the vehicle, avoiding sharp braking and
steering. If a tire puncture occurs, repair
immediately using the dedicated tire repair
kit and contact an authorized dealer as soon
as possible.
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114GETTING TO KNOW YOUR INSTRUMENT PANEL
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The TPMS
malfunction indicator is combined with the low
tire pressure telltale. When the system detects
a malfunction, the telltale will flash for approxi-
mately one minute and then remain continu -
ously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as
the malfunction exists. When the malfunction
indicator is illuminated, the system may not be
able to detect or signal low tire pressure as
intended. TPMS malfunctions may occur for a
variety of reasons, including the installation of
replacement or alternate tires or wheels on the
vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction
telltale after replacing one or more tires or
wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow
the TPMS to continue to function properly.
Anti-Lock Brake (ABS) Warning Light
This warning light monitors the
Anti-Lock Brake System (ABS). The
light will turn on when the ignition is
placed in the ON/RUN or ACC/ON/
RUN position and may stay on for as long as four
seconds.
If the ABS light remains on or turns on while
driving, then the Anti-Lock portion of the brake
system is not functioning and service is
required as soon as possible. However, the conventional brake system will continue to
operate normally, assuming the Brake Warning
Light is not also on.
If the ABS light does not turn on when the igni
-
tion is placed in the ON/RUN or ACC/ON/RUN
position, have the brake system inspected by an
authorized dealer.
Service Forward Collision Warning (FCW)
Light — If Equipped
This warning light will illuminate to
indicate a fault in the Forward Colli -
sion Warning System. Contact an
authorized dealer for service.
Refer to "Forward Collision Warning (FCW)" in
"Safety" for further information.
Service 4WD Warning Light — If Equipped
This warning light will illuminate to
signal a fault with the 4WD system. If
the light stays on or comes on during
driving, it means that the 4WD system
is not functioning properly and that service is
required. We recommend you drive to the
nearest service center and have the vehicle
serviced immediately.
CAUTION!
The TPMS has been optimized for the original
equipment tires and wheels. TPMS pressures
and warning have been established for the
tire size equipped on your vehicle.
Undesirable system operation or sensor
damage may result when using replacement
equipment that is not of the same size, type,
and/or style. Aftermarket wheels can cause
sensor damage. Using aftermarket tire
sealants may cause the Tire Pressure
Monitoring System (TPMS) sensor to become
inoperable. After using an aftermarket tire
sealant it is recommended that you take your
vehicle to an authorized dealer to have your
sensor function checked.

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GETTING TO KNOW YOUR INSTRUMENT PANEL115
Speed Control Fault Warning Light
This warning light will illuminate to
indicate the Speed Control System
is not functioning properly and
service is required. Contact an
authorized dealer.
Yellow Indicator Lights
Forward Collision Warning Off Indicator Light
— If Equipped
This indicator light illuminates to indi -
cate that Forward Collision Warning is
off.
Refer to “Auxiliary Driving Systems” in “Safety”
for further information.
TOW/HAUL Indicator Light
This indicator light will illuminate
when TOW/HAUL mode is selected.
Refer to “Automatic Transmission” in “Starting
And Operating” for further information.
Trailer Merge Assist Indicator Light — If
Equipped
This indicator light will illuminate to
indicate when Trailer Merge Assist
has been activated.
Cargo Light — If Equipped
This indicator light will illuminate
when the cargo light is activated by
pushing the cargo light button on the
headlight switch.
Snowplow Mode Indicator Light — If Equipped
This indicator light will illuminate
when Snowplow Mode has been acti -
vated.
Refer to “Snowplow” in “Starting And Oper -
ating” for further information.
4WD Lock Indicator Light
This light alerts the driver that the
vehicle is in the four-wheel drive LOCK
mode. The front and rear driveshafts
are mechanically locked together, forcing the front and rear wheels to rotate at the
same speed.
Refer to “Four-Wheel Drive Operation” in
“Starting And Operating” for further information
on four-wheel drive operation and proper use.
4WD Low Indicator Light — If Equipped
This light alerts the driver that the
vehicle is in the four-wheel drive LOW
mode. The front and rear driveshafts
are mechanically locked together
forcing the front and rear wheels to rotate at the
same speed. Low range provides a greater gear
reduction ratio to provide increased torque at
the wheels.
Refer to “Four-Wheel Drive Operation — If
Equipped” in “Starting And Operating” for
further information on four-wheel drive opera -
tion and proper use.
4WD High Indicator Light — If Equipped
This light alerts the driver that the
vehicle is in the four-wheel drive HIGH
mode. The front and rear driveshafts
are mechanically locked together
forcing the front and rear wheels to rotate at the
same speed.
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116GETTING TO KNOW YOUR INSTRUMENT PANEL
NEUTRAL Indicator Light — If Equipped
This light alerts the driver that the
4WD power transfer case is in the
NEUTRAL mode and the front and rear
driveshafts are disengaged from the
powertrain.
Cold Ambient Derate Mode Indicator Light —
If Equipped
This indicator light will illuminate
when a derate (engine power reduc -
tion) is activated for protection of the
turbocharger in cold ambient
temperatures.
For further information, refer to “Instrument
Cluster Display” in “Getting To Know Your
Instrument Panel”.
Diesel Exhaust Brake Indicator Light — If
Equipped
This indicator light will illuminate
when the Diesel Exhaust Brake has
been activated, and is in full strength
mode.
Refer to “Diesel Exhaust Brake (Engine
Braking)” in “Starting And Operating” for further
information.
Low Diesel Exhaust Fluid (DEF) Indicator
Light — If Equipped
The Low Diesel Exhaust Fluid (DEF)
Indicator will illuminate if the vehicle
is low on Diesel Exhaust Fluid (DEF).
Refer to “Starting And Operating” for
further information.
Wait To Start Light — If Equipped
This indicator light will illuminate for
approximately two seconds when the
ignition is turned to the RUN position.
Its duration may be longer based on
colder operating conditions. Vehicle will not
initiate start until telltale is no longer displayed.
Refer to “Starting The Engine” in “Starting And
Operating” for further information.
NOTE:
The “Wait To Start” telltale may not illuminate if
the intake manifold temperature is warm
enough.
Water In Fuel Indicator Light — If Equipped
The “Water In Fuel Indicator Light” will
illuminate when there is water
detected in the fuel filter. If this light
remains on, DO NOT start the vehicle before you drain the water from the fuel filter to
prevent engine damage.
Refer to the “Draining Fuel/Water Separator
Filter” section in “Dealer Service” in “Servicing
And Maintenance” for further information.
Green Indicator Lights
Adaptive Cruise Control (ACC) Set With Target
Light — If Equipped
This will display when the ACC is set
and a target vehicle is detected.
Refer to “Adaptive Cruise Control (ACC) — If
Equipped” in “Starting And Operating” for
further information.
Adaptive Cruise Control (ACC) Set With No
Target Detected Indicator Light — If Equipped
This light will turn on when the Adap -
tive Cruise Control is SET and there is
no target vehicle detected.
Refer to "Adaptive Cruise Control (ACC) — If
Equipped" in "Starting And Operating" for
further information.

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118GETTING TO KNOW YOUR INSTRUMENT PANEL
Blue Indicator Lights
High Beam Indicator Light
This indicator light will illuminate to
indicate that the high beam head -
lights are on. With the low beams acti -
vated, push the multifunction lever
forward (toward the front of the vehicle) to turn
on the high beams. Pull the multifunction lever
rearward (toward the rear of the vehicle) to turn
off the high beams. If the high beams are off,
pull the lever toward you for a temporary high
beam on, "flash to pass" scenario.
ONBOARD DIAGNOSTIC SYSTEM — OBD II
Your vehicle is equipped with a sophisticated
Onboard Diagnostic system called OBD II. This
system monitors the performance of the emis -
sions, engine, and transmission control
systems. When these systems are operating
properly, your vehicle will provide excellent
performance and fuel economy, as well as
engine emissions well within current govern -
ment regulations. If any of these systems require service, the OBD
II system will turn on the Malfunction Indicator
Light (MIL). It will also store diagnostic codes
and other information to assist your service
technician in making repairs. Although your
vehicle will usually be drivable and not need
towing, see an authorized dealer for service as
soon as possible.
Onboard Diagnostic System (OBD II)
Cybersecurity
Your vehicle is required to have an Onboard
Diagnostic system (OBD II) and a connection
port to allow access to information related to
the performance of your emissions controls.
Authorized service technicians may need to access this information to assist with the diag
-
nosis and service of your vehicle and emissions
system.
For further information, refer to “Cybersecurity”
in “Multimedia”.
CAUTION!
Prolonged driving with the MIL on could
cause further damage to the emission
control system. It could also affect fuel
economy and driveability. The vehicle must
be serviced before any emissions tests can
be performed.
If the MIL is flashing while the vehicle is
running, severe catalytic converter damage
and power loss will soon occur. Immediate
service is required.
WARNING!
ONLY an authorized service technician
should connect equipment to the OBD II
connection port in order to read the VIN,
diagnose, or service your vehicle.
If unauthorized equipment is connected to
the OBD II connection port, such as a
driver-behavior tracking device, it may:
Be possible that vehicle systems, including safety related systems, could
be impaired or a loss of vehicle control
could occur that may result in an acci -
dent involving serious injury or death.
Access, or allow others to access, infor -
mation stored in your vehicle systems,
including personal information.

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GETTING TO KNOW YOUR INSTRUMENT PANEL119
EMISSIONS INSPECTION AND
MAINTENANCE PROGRAMS
In some localities, it may be a legal requirement
to pass an inspection of your vehicle's emis-
sions control system. Failure to pass could
prevent vehicle registration.
For states that require an Inspection
and Maintenance (I/M), this check
verifies the “Malfunction Indicator
Light (MIL)” is functioning and is not
on when the engine is running, and that the
OBD II system is ready for testing.
Normally, the OBD II system will be ready. The
OBD II system may not be ready if your vehicle
was recently serviced, recently had a depleted
battery or a battery replacement. If the OBD II
system should be determined not ready for the
I/M test, your vehicle may fail the test.
Your vehicle has a simple ignition actuated test,
which you can use prior to going to the test
station. To check if your vehicle's OBD II system
is ready, you must do the following:
1. Cycle the ignition switch to the ON position,
but do not crank or start the engine.

NOTE:
If you crank or start the engine, you will have to
start this test over.
2. As soon as you cycle the ignition switch to the ON position, you will see the “Malfunc -
tion Indicator Light (MIL)” symbol come on
as part of a normal bulb check.
3. Approximately 15 seconds later, one of two things will happen:
The MIL will flash for about 10 seconds
and then return to being fully illuminated
until you turn OFF the ignition or start the
engine. This means that your vehicle's
OBD II system is not ready and you
should not proceed to the I/M station.
The MIL will not flash at all and will
remain fully illuminated until you place
the ignition in the off position or start the
engine. This means that your vehicle's
OBD II system is ready and you can
proceed to the I/M station. If your OBD II system is not ready,
you should
see an authorized dealer or repair facility. If your
vehicle was recently serviced or had a battery
failure or replacement, you may need to do
nothing more than drive your vehicle as you
normally would in order for your OBD II system
to update. A recheck with the above test routine
may then indicate that the system is now ready.
Regardless of whether your vehicle's OBD II
system is ready or not, if the MIL is illuminated
during normal vehicle operation you should
have your vehicle serviced before going to the I/
M station. The I/M station can fail your vehicle
because the MIL is on with the engine running.
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