2021 RAM CHASSIS CAB light

GETTING TO KNOW YOUR INSTRUMENT PANEL107
WARNING LIGHTS AND MESSAGES

The warning/indicator lights will illuminate in the
instrument panel together with a dedicated
message and/or acoustic signal when
applicable. These indications are indicative
and precautionary and as such must not be
considered as exhaustive. Always refer to the
information in this chapter in the event of a
failure indication. All active telltales will display
first if applicable. The system check menu may
appear different based upon equipment options
and current vehicle status. Some telltales are
optional and may not appear.

RED WARNING LIGHTS
Seat Belt Reminder Warning Light

This warning light indicates when
the driver or passenger seat belt is
unbuckled. When the ignition is first
placed in the ON/RUN or ACC/ON/RUN
position and if the driver’s seat belt is unbuckled,
a chime will sound and the light will turn on.
When driving, if the driver or front passenger seat
belt remains unbuckled, the Seat Belt Reminder
Light will flash or remain on continuously and a
chime will sound
Ú
page 292.

Air Bag Warning Light
This warning light will illuminate to
indicate a fault with the air bag, and
will turn on for four to eight seconds
as a bulb check when the ignition
is placed in the ON/RUN or ACC/ON/RUN
position. This light will illuminate with a single
chime when a fault with the air bag has been
detected, it will stay on until the fault is cleared.
If the light is not on during startup, stays on,
or turns on while driving, have the system
inspected at an authorized dealer as soon as
possible.
Brake Warning Light
This warning light monitors various
brake functions, including brake fluid
level and parking brake application.
If the brake light turns on it may
indicate that the parking brake is applied, that
the brake fluid level is low, or that there is a
problem with the Anti-Lock Brake System
reservoir.
If the light remains on when the parking brake
has been disengaged, and the fluid level is at
the full mark on the master cylinder reservoir,
it indicates a possible brake hydraulic system
malfunction or that a problem with the Brake Booster has been detected by the Anti-Lock
Brake System (ABS) / Electronic Stability
Control (ESC) system. In this case, the light
will remain on until the condition has been
corrected. If the problem is related to the brake
booster, the ABS pump will run when applying
the brake, and a brake pedal pulsation may be
felt during each stop.
The dual brake system provides a reserve
braking capacity in the event of a failure to a
portion of the hydraulic system. A leak in either
half of the dual brake system is indicated by the
Brake Warning Light, which will turn on when
the brake fluid level in the master cylinder has
dropped below a specified level.
The light will remain on until the cause is
corrected.
NOTE:
The light may flash momentarily during sharp
cornering maneuvers, which change fluid level
conditions. The vehicle should have service
performed, and the brake fluid level checked.
If brake failure is indicated, immediate repair is
necessary.
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108GETTING TO KNOW YOUR INSTRUMENT PANEL
Vehicles equipped with the Anti-Lock Brake
System (ABS) are also equipped with Electronic
Brake Force Distribution (EBD). In the event of
an EBD failure, the Brake Warning Light will turn
on along with the ABS Light. Immediate repair to
the ABS system is required.

Operation of the Brake Warning Light can be
checked by turning the ignition switch from the
OFF position to the ON/RUN position. The light
should illuminate for approximately two seconds.
The light should then turn off unless the parking
brake is applied or a brake fault is detected. If the
light does not illuminate, have the light inspected
by an authorized dealer.

The light also will turn on when the parking
brake is applied with the ignition switch in the
ON/RUN position. NOTE:
This light shows only that the parking brake is
applied. It does not show the degree of brake
application.
Hood Open Warning Light
This warning light will illuminate when
the hood is ajar/open and not fully
closed.
NOTE:
If the vehicle is moving, there will also be a
single chime.
Vehicle Security Warning Light — If
Equipped
This light will flash at a fast rate for
approximately 15 seconds when the
vehicle security alarm is arming, and
then will flash slowly until the vehicle
is disarmed.
Engine Coolant Temperature Warning
Light
This warning light warns of an
overheated engine condition. If the
engine coolant temperature is too
high, this indicator will illuminate and
a single chime will sound. If the temperature reaches the upper limit, a continuous chime will
sound for four minutes or until the engine is
able to cool, whichever comes first.
If the light turns on while driving, safely pull over
and stop the vehicle. If the Air Conditioning
(A/C) system is on, turn it off. Also, shift the
transmission into NEUTRAL and idle the vehicle.
If the temperature reading does not return to
normal, turn the engine off immediately and call
for service Ú
page 346.
Battery Charge Warning Light
This warning light will illuminate when
the battery is not charging properly.
If it stays on while the engine is
running, there may be a malfunction
with the charging system. Contact an
authorized dealer as soon as possible.
This indicates a possible problem with the
electrical system or a related component.
Oil Pressure Warning Light
This warning light will illuminate to
indicate low engine oil pressure. If the
light turns on while driving, stop the
vehicle, shut off the engine as soon as
possible, and contact an authorized dealer.
A chime will sound when this light turns on.
WARNING!
Driving a vehicle with the red brake light on is
dangerous. Part of the brake system may
have failed. It will take longer to stop the
vehicle. You could have a collision. Have the
vehicle checked immediately.

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GETTING TO KNOW YOUR INSTRUMENT PANEL109
Do not operate the vehicle until the cause is
corrected. This light does not indicate how
much oil is in the engine. The engine oil level
must be checked under the hood.
Oil Temperature Warning Light
This warning light will illuminate to
indicate the engine oil temperature is
high. If the light turns on while driving,
stop the vehicle and shut off the
engine as soon as possible. Wait for oil
temperature to return to normal levels.
Electronic Throttle Control (ETC) Warning
Light
This warning light will illuminate to
indicate a problem with the ETC
system. If a problem is detected while
the vehicle is running, the light will
either stay on or flash depending on the nature
of the problem. Cycle the ignition when the
vehicle is safely and completely stopped and
the transmission is placed in the PARK position.
The light should turn off. If the light remains
on with the vehicle running, your vehicle will
usually be drivable; however, see an authorized
dealer for service as soon as possible. NOTE:
This light may turn on if the accelerator and
brake pedals are pressed at the same time.
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 (EPS) Fault
Warning Light
This warning light will turn on when
there's a fault with the EPS system
Ú
page 163.
Trailer Brake Disconnected Warning Light
This warning light will illuminate when
the Trailer Brake has been
disconnected Ú page 200.
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.
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.
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110GETTING TO KNOW YOUR INSTRUMENT PANEL
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 Ú page 166.
Engine Check/Malfunction Indicator
Warning Light (MIL)
The Engine Check/Malfunction
Indicator Light (MIL) is a part of an
Onboard Diagnostic System called
OBD II that monitors engine and
automatic 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.
CAUTION!
Continuous driving with the Transmission
Temperature Warning Light illuminated will
eventually cause severe transmission
damage or transmission failure.
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 PANEL111
Electronic Stability Control (ESC) Active
Warning Light — If Equipped

This warning light will indicate when
the ESC 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 activated. It should go
out with the engine running. If the ESC Indicator
Light comes on continuously 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 diagnosed and corrected.

The ESC OFF Indicator Light and the ESC Indi -
cator 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 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.
Low Washer Fluid Warning Light — If
Equipped
This warning light will illuminate when
the windshield washer fluid is low
Ú page 364.
Low Fuel Warning Light
When the fuel level reaches
approximately 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
Ú page 367.
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
indications corresponding to each tire.
3

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GETTING TO KNOW YOUR INSTRUMENT PANEL113
Anti-Lock Brake System (ABS) Warning
Light

This warning light monitors the 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 ignition 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 Collision
Warning System. Contact an authorized
dealer for service
Ú
page 281.

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.
Cruise Control Fault Warning Light

This warning light will illuminate to
indicate the Cruise Control System is
not functioning properly and service is
required. Contact an authorized dealer.

YELLOW INDICATOR LIGHTS
Forward Collision Warning (FCW) Off
Indicator Light — If Equipped
This indicator light illuminates to
indicate that Forward Collision
Warning is off Ú page 281.
TOW/HAUL Indicator Light
This indicator light will illuminate
when TOW/HAUL mode is selected.
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
activated Úpage 212.
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114GETTING TO KNOW YOUR INSTRUMENT PANEL
Cold Ambient Derate Mode Indicator
Light — If Equipped
This indicator light will illuminate
when a derate (engine power
reduction) is activated for protection
of the turbocharger in cold ambient
temperatures.
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 Ú page 138.
4WD Lock Indicator Light
This light alerts the driver that the
vehicle is in the 4WD LOCK mode.
The front and rear driveshafts are
mechanically locked together, forcing
the front and rear wheels to rotate at the same
speed Ú page 153.
4WD Low Indicator Light — If Equipped
This light alerts the driver that the
vehicle is in the 4WD 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 Ú
page 153.
4WD High Indicator Light — If Equipped
This light alerts the driver that the
vehicle is in the 4WD High mode.
The front and rear driveshafts are
mechanically locked together forcing
the front and rear wheels to rotate at the same
speed.
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.
Low Diesel Exhaust Fluid (DEF) Indicator
Light — If Equipped

The Low DEF Indicator will illuminate if
the vehicle is low on DEF
Ú
page 379.

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
Ú page 122.
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 Ú page 375.

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GETTING TO KNOW YOUR INSTRUMENT PANEL115
GREEN INDICATOR LIGHTS
Adaptive Cruise Control (ACC) Set With
Target Light — If Equipped
This will display when the ACC is set
and a the vehicle in front is detected
Úpage 166.
Adaptive Cruise Control (ACC) Set With
No Target Detected Indicator Light — If
Equipped
This light will turn on when the
Adaptive Cruise Control is SET and
there is no vehicle in front detected
Úpage 166.
Automatic Diesel Exhaust Brake Indicator
Light — If Equipped
This indicator light will illuminate
when the Diesel Exhaust Brake has
been activated, and has switched to
Automatic mode Ú page 164.
ECO Mode Indicator Light — If Equipped
This light will turn on when ECO Mode
is active.
Park/Headlight On Indicator Light
This indicator light will illuminate
when the park lights or headlights are
turned on.
Front Fog Indicator Light — If Equipped
This indicator light will illuminate
when the front fog lights are on.
Turn Signal Indicator Lights
When the left or right turn signal is
activated, the turn signal indicator
will flash independently and the
corresponding exterior turn signal
lamps will flash. Turn signals can be activated
when the multifunction lever is moved down
(left) or up (right).
NOTE:
A continuous chime will sound if the vehicle is
driven more than 1 mile (1.6 km) with either
turn signal on.
Check for an inoperative outside light bulb if
either indicator flashes at a rapid rate.
If equipped with fog lamps, the fog lamp on
the side of the activated turn signal will also
illuminate to provide additional light when
turning.
Cruise Control Set Indicator Light — If
Equipped
This indicator light will illuminate
when the cruise control is set to the
desired speed Ú page 164.
WHITE INDICATOR LIGHTS
Adaptive Cruise Control (ACC) Ready
Light — If Equipped
This light will illuminate when the
vehicle equipped with ACC has been
turned on but not set Ú page 166.
Cruise Control Ready Indicator
This indicator light will illuminate
when the cruise control is ready, but
not set Úpage 164.
Set Speed Display
The Set Speed Display indicator light
indicates the set speed for the Speed
Control and ACC settings.
3

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