2021 RAM 1500 light

134GETTING TO KNOW YOUR INSTRUMENT PANEL
Air Suspension Normal Height Indicator
Light— If Equipped
This light will illuminate when the air
suspension system is set to the
Normal setting Úpage 165.
Air Suspension Aerodynamic Height
Indicator Light— If Equipped
This light will illuminate when the air
suspension system is set to the
Aerodynamic setting.
Entry/Exit Indicator Light— If Equipped
This light will illuminate when the
vehicle is automatically lowered from
ride height position downward for
easy entry and exit of the vehicle
Úpage 165.
Air Suspension Ride Height Raising
Indicator Light— If Equipped
This light will blink and alert the driver
that the vehicle is changing to a
higher ride height.
Air Suspension Ride Height Lowering
Indicator Light— If Equipped
This light will blink and alert the driver
that the vehicle is changing to a lower
ride height.
Rear Axle Lock Indicator Light
This light indicates when the rear axle
lock has been activated.
4WD Indicator Light — If Equipped
This light alerts the driver that the
vehicle is in the four-wheel drive
mode, and the front and rear
driveshafts are mechanically locked
together forcing the front and rear wheels to
rotate at the same speed.
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 161.
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 Diesel Exhaust
Fluid (DEF) Ú page 211.

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GETTING TO KNOW YOUR INSTRUMENT PANEL135
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 146.
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, and please see an
authorized dealer.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
Ú page 179.
Adaptive Cruise Control (ACC) Set With No
Target Detected Indicator Light — If
Equipped
This light will turn on when the ACC is
SET and there is no target vehicle
detected Ú page 179.
ECO Mode Indicator Light
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.
LaneSense Indicator Light — If Equipped
The LaneSense indicator light
illuminates solid green when both
lane markings have been detected
and the system is “armed” and ready
to provide visual and torque warnings if an
unintentional lane departure occurs
Ú page 199.
CAUTION!
The presence of water in the fuel system
circuit may cause severe damage to the
injection system and irregular engine
operation. If the indicator light is illuminated,
contact an authorized dealer as soon as
possible to bleed the system. If the above
indications come on immediately after
refuelling, water has probably been poured
into the tank: switch the engine off
immediately and contact an authorized
dealer.
3

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136GETTING TO KNOW YOUR INSTRUMENT PANEL
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 With Premium Instrument
Cluster Display
This light will turn on when the cruise
control is set Ú page 177.
Stop/Start Active Indicator Light — If
Equipped
This indicator light will illuminate
when the Stop/Start function is in
“Autostop” mode Ú page 175.
4WD AUTO Indicator Light — If Equipped
This light alerts the driver that the
vehicle is in the four-wheel drive auto
mode, and the front axle is engaged,
but the vehicle's power is sent to the
rear wheels. Four-wheel drive will be
automatically engaged when the vehicle senses
a loss of traction Ú page 161.
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 179.
Cruise Control Ready Indicator
This indicator light will illuminate
when the cruise control is ready, but
not set Úpage 177.
Cruise Control SET Indicator Light — If
Equipped With Base/Midline Instrument
Cluster Display
This light will turn on when the cruise
control is set Ú page 177.

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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.
3

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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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STARTING AND OPERATING141
(Continued)
NOTE:
Engine start up in very low ambient temperature
could result in evident white smoke. This condi -
tion will disappear as the engine warms up.
AUTOMATIC TRANSMISSION
Start the engine with the transmission in PARK
position. Apply the brake before shifting into any
driving range.
NOTE:
This vehicle is equipped with a transmission
shift interlocking system. The brake pedal
must be pressed to shift out of PARK.
If equipped with an 8-speed transmission,
starting the vehicle in NEUTRAL is not
possible unless the Manual Park Release has
been activated Ú page 390.
AUTOPARK
AutoPark is a supplemental feature to assist in
placing the vehicle in PARK should the
situations on the following pages occur. It is a
back up system and should not be relied upon as the primary method by which the driver shifts
the vehicle into PARK.
The conditions under which AutoPark will
engage are outlined on the following pages.
Do not leave the key fob in or near the
vehicle, or in a location accessible to chil-
dren, and do not leave the ignition of 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.
Do not leave children or animals inside
parked vehicles in hot weather. Interior
heat build-up may cause serious injury or
death.
CAUTION!
The engine is allowed to crank as long as
25 seconds. If the engine fails to start
during this period, please wait at least two
minutes for the starter to cool before
repeating start procedure.
WARNING!
(Continued)
If the “Water in Fuel Indicator Light”
remains on, DO NOT START engine before
you drain the water from the fuel filter to
avoid engine damage Ú page 412.
CAUTION! (Continued)
WARNING!
Driver inattention could lead to failure to
place the vehicle in PARK. ALWAYS DO A
VISUAL CHECK that your vehicle is in PARK
by verifying that a solid (not blinking) “P” is
indicated in the instrument cluster display
and near the gear selector. If the “P” indi -
cator is blinking, your vehicle is not in
PARK. As an added precaution, always
apply the parking brake when exiting the
vehicle.
AutoPark is a supplemental feature. It is not
designed to replace the need to shift your
vehicle into PARK. It is a back up system
and should not be relied upon as the
primary method by which the driver shifts
the vehicle into PARK.
4

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STARTING AND OPERATING145
NOTE:
A delay of the start, up to five seconds is
possible under very cold conditions. The "Wait
to Start" telltale will be illuminated during the
pre-heat process. When the engine “Wait To
Start” light goes off the engine will automati -
cally crank.
3. The system starts the vehicle. If the vehicle fails to start, the starter will disengage
automatically after 25 seconds.
4. If you wish to stop the cranking of the engine prior to the engine starting, push the
button again.
NOTE:
Normal starting of either a cold or a warm
engine is obtained without pumping or pressing
the accelerator pedal. To Turn Off The Engine Using ENGINE START/
STOP Button

1. Place the gear selector in PARK, then push
and release the ENGINE START/STOP
button. The ignition will return to the OFF
mode.

2. If the gear selector is not in PARK, the ENGINE START/STOP button must be held
for two seconds or three short pushes in a
row with the vehicle speed above 5 mph
(8 km/h) before the engine will shut off. The
ignition will remain in the ACC mode until
the gear selector is in PARK and the button
is pushed twice to the OFF mode.
3. If the gear selector is not in PARK and the ENGINE START/STOP button is pushed
once with the vehicle speed above 5 mph
(8 km/h), the instrument cluster will display
a “Vehicle Not In Park ” message and the
engine will remain running. Never leave a
vehicle out of the PARK position, or it could
roll.
NOTE:
If the gear selector is not in PARK, and the
ENGINE START/STOP button is pushed once
with the vehicle speed below 5 mph (8 km/h), the engine will shut off and the ignition will
remain in the ACC position. If vehicle speed
drops below 1.2 mph (1.9 km/h), the vehicle
may AutoPark Ú
page 141.
ENGINE START/STOP Button Functions — With
Driver’s Foot OFF The Brake Pedal (In PARK Or
NEUTRAL Position)
The ENGINE START/STOP button operates
similar to an ignition switch. It has three modes:
OFF, ACC, and RUN. To change the ignition
modes without starting the vehicle and use the
accessories, follow these directions:

1. Start with the ignition in the OFF mode.

2. Push the ENGINE START/STOP button once to place the ignition to the ACC mode.
3. Push the ENGINE START/STOP button a second time to place the ignition to the RUN
mode.
4. Push the ENGINE START/STOP button a third time to return the ignition to the OFF
mode.
CAUTION!
If the “Water in Fuel Indicator Light” remains
on, DO NOT START the engine before you
drain the water from the fuel filter to avoid
engine damage Ú page 412.4

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146STARTING AND OPERATING
(Continued)
COLD WEATHER OPERATION (BELOW
–22°F O
R −30°C)
To ensure reliable starting at these
temperatures, use of an externally powered
electric engine block heater (available from an
authorized dealer) is recommended.
AFTER STARTING
The idle speed is controlled automatically, and
it will decrease as the engine warms up.
STARTING FLUIDS — DIESEL ENGINE
O
NLY
The engine is equipped with a glow plug
preheating system. If the instructions in this
manual are followed, the engine should start in
all conditions and no type of starting fluid
should be used.
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the diesel engine is
operating.
All message center lights are off.
Malfunction Indicator Light (MIL) is off.
Engine Oil Pressure telltale is not illuminated.
Voltmeter operation:
The voltmeter may show a gauge fluctuation at
various engine temperatures. This is caused by
the glow plug heating system. The number of
cycles and the length of the cycling operation is
controlled by the engine control module. Glow
plug heater operation can run for several
minutes, once the heater operation is complete
the voltmeter needle will stabilize.
COLD WEATHER PRECAUTIONS
Operation in ambient temperature below 32°F
(0°C) may require special considerations. The
following charts suggest these options:
WARNING!
Do not leave children or animals inside
parked vehicles in hot weather. Interior
heat build up may cause serious injury or
death.
When leaving the vehicle, always make
sure the wireless ignition node is in the
“OFF” mode, remove the key fob from the
vehicle and lock the 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 the ignition of 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.
WARNING! (Continued)

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