2021 RAM 1500 service indicator

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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130GETTING TO KNOW YOUR INSTRUMENT PANEL
Engine Check/Malfunction Indicator
Warning Light (MIL)
The 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.
Electronic Park Brake Warning Light
This warning light will illuminate to
indicate the Electronic Park Brake is
not functioning properly and service is
required. Contact an authorized
dealer.
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.
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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132GETTING 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
approximately one minute and then remain
continuously 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 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.
Rear Axle Locker Fault Indicator Light — If
Equipped
This warning light will illuminate to
indicate when a rear axle locker fault
has been detected.
Service Forward Collision Warning (FCW)
Light — If Equipped
This warning light will illuminate to
indicate a fault in the FCW System.
Contact an authorized dealer for
service Ú
page 324.
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.

21_DT_OM_EN_USC_t.book Page 132

GETTING TO KNOW YOUR INSTRUMENT PANEL133
Service Stop/Start System Warning Light —
If Equipped
This warning light will illuminate when
the Stop/Start system is not
functioning properly and service is
required. Contact an authorized
dealer for service.
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 Off Indicator
Light — If Equipped
This indicator light illuminates to
indicate that Forward Collision
Warning is off.
Air Suspension Payload Protection
Indicator Light — If Equipped
This indicator light will illuminate to
indicate that the maximum payload
may have been exceeded or load
leveling cannot be achieved at its
current ride height. Protection Mode will
automatically be selected to “protect” the air
suspension system, air suspension adjustment
is limited due to payload.
Trailer Merge Assist Indicator Light — If
Equipped
This indicator light will illuminate to
indicate when Trailer Merge Assist
has been activated Ú page 318.
TOW/HAUL Indicator Light
This indicator light will illuminate
when TOW/HAUL mode is selected.
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.
Air Suspension Off-Road 1 Indicator Light
— If Equipped
This light will illuminate when the air
suspension system is set to the
Off-Road 1 setting Úpage 165.
Air Suspension Off-Road 2 Indicator Light
— If Equipped
This light will illuminate when the air
suspension system is set to the
Off-Road 2 setting Úpage 165.
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GETTING TO KNOW YOUR INSTRUMENT PANEL137
Hill Descent Control (HDC) Indicator Light
— If Equipped
This indicator shows when the HDC
feature is turned on. The lamp will be
on solid when HDC is armed. HDC can
only be armed when the transfer case
is in the “4WD LOW” position and the vehicle
speed is less then 20 mph (32 km/h). If these
conditions are not met while attempting to use
the HDC feature, the HDC indicator light will
flash on/off.
LaneSense Indicator Light — If Equipped
When the LaneSense system is ON,
but not armed, the LaneSense
indicator light illuminates solid white.
This occurs when only left, right, or
neither lane line has been detected. If a single
lane line is detected, the system is ready to
provide only visual warnings if an unintentional
lane departure occurs on the detected lane line
Ú page 199.
BLUE INDICATOR LIGHTS
High Beam Indicator Light
This indicator light will illuminate to
indicate that the high beam
headlights are on. With the low beams
activated, 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
emissions, 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
government 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.
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.
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138GETTING TO KNOW YOUR INSTRUMENT PANEL
ONBOARD DIAGNOSTIC SYSTEM
(OBD II) C
YBERSECURITY
Your vehicle is required to have 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 diagnosis and service of your vehicle and
emissions system Ú page 236.
EMISSIONS INSPECTION AND
MAINTENANCE PROGRAMS
In some localities, it may be a legal requirement
to pass an inspection of your vehicle's
emissions 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
Malfunction 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.
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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152STARTING AND OPERATING
(Continued)
NOTE:
The EPB fault light will illuminate if the EPB
switch is held for longer than 20 seconds in
either the released or applied position. The light
will extinguish upon releasing the switch.
If the Auto Park Brake feature is enabled, the
parking brake will automatically engage
whenever the transmission is placed into PARK.
If your foot is on the brake pedal, you may notice
a small amount of brake pedal movement while
the parking brake is engaging.
The parking brake will release automatically
when the ignition is ON, the transmission is in
DRIVE or REVERSE, the driver seat belt is
buckled, and an attempt is made to drive away.
To release the parking brake manually, the
ignition switch must be in the ON/RUN mode.
Put your foot on the brake pedal, then push the
parking brake switch down momentarily. You
may hear a slight whirring sound from the back
of the vehicle while the parking brake
disengages. You may also notice a small
amount of movement in the brake pedal. Once
the parking brake is fully disengaged, The
BRAKE telltale light in the instrument cluster
and the LED indicator on the switch will
extinguish.NOTE:
When parking on a hill, it is important to turn the
front wheels toward the curb on a downhill
grade and away from the curb on an uphill
grade. Apply the parking brake before placing
the gear selector in PARK, otherwise the load on
the transmission locking mechanism may make
it difficult to move the gear selector out of PARK.
WARNING!
Never use the PARK position as a substi
-
tute for the parking brake. Always apply the
parking brake fully when parked to guard
against vehicle movement and possible
injury or damage.
When exiting the vehicle, always remove
the key fob from the ignition and lock your
vehicle.
Never leave children alone in a vehicle, or
with access to an unlocked vehicle.
Allowing children to be in a vehicle unat -
tended is dangerous for a number of
reasons. A child or others could be seriously
or fatally injured. Children should be
warned not to touch the parking brake,
brake pedal or the gear selector.
Do not leave the key fob in or near the
vehicle, or in a location accessible to chil -
dren, and do not leave a vehicle equipped
with Keyless Enter-N-Go in the ACC or ON/
RUN mode. A child could operate power
windows, other controls, or move the
vehicle.
Be sure the parking brake is fully disen -
gaged before driving; failure to do so can
lead to brake failure and a collision.
Always fully apply the parking brake when
leaving your vehicle, or it may roll and
cause damage or injury. Also be certain to
leave the transmission in PARK. Failure to
do so may allow the vehicle to roll and
cause damage or injury.
CAUTION!
If the Brake System Warning Light remains on
with the parking brake released, a brake
system malfunction is indicated. Have the
brake system serviced by an authorized
dealer immediately.
WARNING! (Continued)

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154STARTING AND OPERATING
(Continued)
(Continued)
Fortunately, actuator retraction can be done
easily by entering the Brake Service Mode
through the Uconnect Settings in your vehicle.
This menu based system will guide you through
the steps necessary to retract the EPB actuator
in order to perform rear brake service.
Service Mode has requirements that must be
met in order to be activated:
The vehicle must be at a standstill.
The parking brake must be unapplied.
The transmission must be in PARK or
NEUTRAL.
While in Service Mode, the EPB fault lamp will
flash continuously while the ignition is ON.
When brake service work is complete, the
following steps must be followed to reset the
park brake system to normal operation:
Ensure the vehicle is at a standstill.
Press the brake pedal with moderate force.
Apply the EPB Switch.
AUTOMATIC TRANSMISSION
You must press and hold the brake pedal while
shifting out of PARK.
WARNING!
You can be badly injured working on or
around a motor vehicle. Do only that service
work for which you have the knowledge and
the right equipment. If you have any doubt
about your ability to perform a service job,
take your vehicle to a competent mechanic.
WARNING!
Never use the PARK position as a substi -
tute for the parking brake. Always apply the
parking brake fully when exiting the vehicle
to guard against vehicle movement and
possible injury or damage.
Your vehicle could move and injure you and
others if it is not in PARK. Check by trying to
move the transmission gear selector out of
PARK with the brake pedal released. Make
sure the transmission is in PARK before
exiting the vehicle.
The transmission may not engage PARK if
the vehicle is moving. Always bring the
vehicle to a complete stop before shifting to
PARK, and verify that the transmission gear
position indicator solidly indicates PARK (P)
without blinking. Ensure that the vehicle is
completely stopped, and the PARK position
is properly indicated, before exiting the
vehicle.
It is dangerous to shift out of PARK or
NEUTRAL if the engine speed is higher than
idle speed. If your foot is not firmly pressing
the brake pedal, the vehicle could accel -
erate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and your
foot is firmly pressing the brake pedal.
WARNING! (Continued)

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