2021 RAM 1500 warning light

GETTING TO KNOW YOUR INSTRUMENT PANEL117
Adaptive Cruise Control (ACC) Feature
The instrument cluster display displays the
current Adaptive Cruise Control (ACC) system
settings. The information displayed depends on
ACC system status.
Push the Adaptive Cruise Control (ACC) on/off
button (located on the steering wheel) until one
of the following displays in the instrument
cluster display:
Adaptive Cruise Control Off
When ACC is deactivated, the display will read
“Adaptive Cruise Control Off.”
Adaptive Cruise Control Ready
When ACC is activated but the vehicle speed
setting has not been selected, the display will
read “Adaptive Cruise Control Ready.”
Push the SET + or the SET- button (located on
the steering wheel) and the following will display
in the instrument cluster display:
ACC SET
When ACC is set, the set speed will display in
the instrument cluster Úpage 179.The ACC screen may display once again if any
ACC activity occurs, which may include any of
the following:
Distance Setting Change
System Cancel
Driver Override
System Off
ACC Proximity Warning
ACC Unavailable Warning
LaneSense — If Equipped
The instrument cluster display displays the
current LaneSense system settings. The
information displayed depends on LaneSense
system status and the conditions that need to
be met Ú page 137.
Fuel Economy
Push and release the up or down arrow
button until the Fuel Economy menu item is
highlighted in the instrument cluster display.
Push and hold the OK button to reset Average
Fuel Economy.
Current Fuel Economy
Average Fuel Economy
Range To Empty
Trip Info
Push and release the up or down arrow
button until the Trip menu item is highlighted in
the instrument cluster display. Push and
release the right or left arrow button to
enter the submenus of Trip A and Trip B. The
Trip A or Trip B information will display the
following:
Distance
Average Fuel Economy
Elapsed Time
Push and hold OK button to reset all
information.
Stop/Start — If Equipped
Push and release the up or down arrow
button until the Stop/Start icon/title is
highlighted in the instrument cluster display.
The screen will display the Stop/Start status.
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118GETTING TO KNOW YOUR INSTRUMENT PANEL
Trailer Tow
Push and release the up or down arrow
button until the Trailer Tow menu item is
highlighted in the instrument cluster display.
Push and release the right or left arrow
button to cycle through the following trailer tow
information:
Trip (trailer specific) Distance: Push and hold
the OK button to reset the distance.
Integrated Trailer Brake Module (ITBM):
Braking Output
Trailer Type
ITBM Gain
Trailer Light Check: Push and hold the OK
button to begin the Trailer Light Test
sequence Ú page 225.
Trailer Tire Pressure Monitoring: The Instru-
ment Cluster Display will display the Trailer
Tire Pressure for a connected trailer with
sensors that match the active trailer profile.
When a low tire is present, the low tire value
will be displayed in red, and the affected low
tire will have a red glow. “Trailer Tire Low“ will
be displayed on the center bottom of the
Instrument Cluster Display screen.
Audio
Push and release the up or down arrow
button until the Audio Menu icon/title is
highlighted in the instrument cluster display.
This menu will display the audio source
information, including the Song name, Artist
name, and audio source with an accompanying
graphic.
Phone Call Status
When a call is incoming, a Phone Call Status
pop-up will display on the screen. The pop-up
will remain until the phone is answered or
ignored.
NOTE:
The call status will temporarily replace the
previous media source information displayed
on the screen. When the pop-up is no longer
displayed, the display will return to the last used
screen.
Stored Messages
Push and release the up or down arrow
button until the Messages Menu item is
highlighted. This feature shows the number of
stored warning messages. Push and release the
right or left arrow button to cycle through
stored messages.
Settings
Head-Up Display (HUD)
NOTE:
The HUD feature Settings are available at any
vehicle speed.
Push and release the up or down arrow
button until the Settings Menu icon/title is
highlighted in the instrument cluster display.
Push and release the left or right arrow
button until the HUD Menu icon/title is
highlighted in the instrument cluster
display.Push and release the OK button to enter
HUD. Use the up or down arrow button to
select a setting, then push and release the OK
button to adjust the setting.
ON/OFF
Content and Layout
Simple : Speed, Speed Limit
Standard : Speed, Speed Limit, Naviga-
tion
Advanced : Speed, Speed Limit, Naviga-
tion, Driver Assist (ACC/Cruise, Lane -
Sense, Highway Assist/Highway Assist+),
Gear

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124GETTING TO KNOW YOUR INSTRUMENT PANEL
DIESEL EXHAUST FLUID (DEF) FAULT
W
ARNING MESSAGES
There are different messages which are
displayed if the vehicle detects that the DEF
system has been filled with a fluid other than
DEF, has experienced component failures, or
when tampering has been detected.
When the DEF system needs to be serviced the
following warnings will display:
Service DEF System See Dealer — This
message will display when the fault is initially
detected and each time the vehicle is
started. The message will be accompanied by
a single chime and the Malfunction Indicator
Light. We recommend you drive to the
nearest authorized dealer and have your
vehicle serviced immediately. If not corrected
in 50 miles, vehicle will enter the “Engine Will
not restart in XXX mi Service DEF See dealer”
warning stage and message.
Incorrect DEF Detected See Dealer — This
message will display if the DEF system has
detected the incorrect fluid has been intro -
duced to the DEF tank. The message will be
accompanied by a single chime. We recom -
mend you drive to your nearest authorized dealer and have your vehicle serviced imme
-
diately. If not corrected in 30 miles, vehicle
will enter the “Engine Will not restart in XXX
mi Service DEF See dealer” warning stage
and message.
Engine Will Not Restart in XXX mi Service DEF
See Dealer — This message is first displayed
if the fault detected is not serviced after
50 miles of operation. It is also displayed at
150 miles, 125 miles and 100 miles. System
service is required within the displayed
mileage. The message will be displayed
during vehicle start up with an updated
distance mileage, and it will be accompanied
by a single chime. Starting at 100 miles,
remaining range will be continuously
displayed while operating the vehicle.
Chimes will also accompany the 75, 50 and
25 mile remaining distances. We recom -
mend you drive to the nearest authorized
dealer and have your vehicle serviced imme -
diately.
Engine Will Not Restart Service DEF System
See Dealer — This message will display if DEF
system issue detected is not serviced during
the allowed period. Your engine will not
restart unless your vehicle is serviced by an
authorized dealer. This message will be displayed when under 1 mile until engine will
not start and each time the vehicle is started,
and will be continuously displayed. The
message will be accompanied by a single
chime. Your Malfunction Indicator Light will
be continuously illumined. We highly recom-
mend you drive to the nearest authorized
dealer if the message appears while engine
is running.
Engine Will Not Start Service DEF System See
Dealer — This message will display when the
fault detected is not serviced after the Engine
will not restart Service DEF System See
Dealer message is displayed on the next
subsequent restart. Your engine will not start
unless your vehicle is serviced by an autho-
rized dealer. The message will be accompa
-
nied by a single chime. Your Malfunction
Indicator Light will be continuously illumi -
nated. If the message appears and you can
not start the engine, we recommend having
your vehicle towed to the nearest authorized
dealer immediately.

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GETTING TO KNOW YOUR INSTRUMENT PANEL125
BATTERY SAVER ON/BATTERY SAVER
M
ODE MESSAGE — ELECTRICAL LOAD
R
EDUCTION ACTIONS — IF EQUIPPED
This vehicle is equipped with an Intelligent
Battery Sensor (IBS) to perform additional
monitoring of the electrical system and status
of the vehicle battery.
In cases when the IBS detects charging system
failure, or the vehicle battery conditions are
deteriorating, electrical load reduction actions
will take place to extend the driving time and
distance of the vehicle. This is done by reducing
power to or turning off non-essential electrical
loads.
Load reduction is only active when the engine is
running. It will display a message if there is a
risk of battery depletion to the point where the
vehicle may stall due to lack of electrical supply,
or will not restart after the current drive cycle.
When load reduction is activated, the message
“Battery Saver On Some Systems May Have
Reduced Power” will appear in the instrument
cluster.
These messages indicate the vehicle battery
has a low state of charge and continues to lose electrical charge at a rate that the charging
system cannot sustain.
NOTE:The charging system is independent from
load reduction. The charging system
performs a diagnostic on the charging
system continuously.
If the Battery Charge Warning Light is on it
may indicate a problem with the charging
system Ú
page 128.
The electrical loads that may be switched off (if
equipped), and vehicle functions which can be
affected by load reduction:
Heated Seats / Vented Seats / Heated Wheel
Rear Defroster And Heated Mirrors
HVAC System
115 Volts AC Power Inverter System
Audio and Telematics System
Loss of the battery charge may indicate one or
more of the following conditions:
The charging system cannot deliver enough
electrical power to the vehicle system
because the electrical loads are larger than the capability of charging system. The
charging system is still functioning properly.
Turning on all possible vehicle electrical
loads (e.g. HVAC to max settings, exterior and
interior lights, overloaded power outlets
+12 Volts, 115 Volts AC, USB ports) during
certain driving conditions (city driving,
towing, frequent stopping).
Installing options like additional lights,
upfitter electrical accessories, audio
systems, alarms and similar devices.
Unusual driving cycles (short trips separated
by long parking periods).
The vehicle was parked for an extended
period of time (weeks, months).
The battery was recently replaced and was
not charged completely.
The battery was discharged by an electrical
load left on when the vehicle was parked.
The battery was used for an extended period
with the engine not running to supply radio,
lights, chargers, +12 Volt portable appli
-
ances like vacuum cleaners, game consoles
and similar devices.
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126GETTING TO KNOW YOUR INSTRUMENT PANEL
What to do when an electrical load reduction
action message is present (“Battery Saver On”
or “Battery Saver Mode”)
During a trip:
Reduce power to unnecessary loads if
possible:
Turn off redundant lights (interior or exte-
rior).
Check what may be plugged in to power
outlets +12 Volts, 115 Volts AC, USB
ports.
Check HVAC settings (blower, tempera -
ture).
Check the audio settings (volume).
After a trip:
Check if any aftermarket equipment was
installed (additional lights, upfitter electrical
accessories, audio systems, alarms) and
review specifications if any (load and Ignition
Off Draw currents).
Evaluate the latest driving cycles (distance,
driving time and parking time).
The vehicle should have service performed if
the message is still present during consecu -tive trips and the evaluation of the vehicle
and driving pattern did not help to identify the
cause.
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 and/or alternative to
the information contained in the Owner’s
Manual, which you are advised to read carefully
in all cases. 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 334.
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 either 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

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GETTING TO KNOW YOUR INSTRUMENT PANEL127
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.
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 system is arming, and
then will flash slowly until the vehicle
is disarmed.
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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128GETTING TO KNOW YOUR INSTRUMENT PANEL
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 (N) and idle the
vehicle. If the temperature reading does not
return to normal, turn the engine off
immediately and call for service Ú page 389.
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.
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.

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GETTING TO KNOW YOUR INSTRUMENT PANEL129
Electric Power Steering (EPS) Fault
Warning Light
This warning light will turn on when
there's a fault with the EPS system
Úpage 174.
Tailgate Open Warning Light
This warning light will illuminate when
the tailgate is open.
NOTE:
If the vehicle is moving, there will also be a
single chime.
Trailer Brake Disconnected Warning Light
This warning light will illuminate when
the Trailer Brake has been
disconnected.
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 an authorized dealer for
service Ú page 179.
Air Suspension Fault Warning Light — If
Equipped
This light will illuminate when a fault is
detected with the air suspension
system.
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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