2021 RAM 1500 brake light

STARTING AND OPERATING165
NOTE:
Do not attempt to make a shift while only the
front or rear wheels are spinning. This could
cause damage to driveline components.
When operating your vehicle in 4WD Low, the
engine speed is approximately three times that
of the 2WD, 4WD Auto or 4WD High positions
at a given road speed. Take care not to
overspeed the engine and do not exceed
25 mph (40 km/h).
Proper operation of four-wheel drive vehicles
depends on tires of equal size, type and
circumference on each wheel. Any difference in
tire size can cause damage to the drivetrain.
Because four-wheel drive provides improved
traction, there is a tendency to exceed safe
turning and stopping speeds. Do not go faster
than road conditions permit.
Shifting Procedure
If any of the requirements to select a new
transfer case position have not been met,
then the transfer case will not shift. The posi -
tion indicator light for the previous position
will remain on and the newly selected posi -
tion indicator light will continue to flash until
all the requirements for the selected position
have been met.
If all the requirements to select a new
transfer case position have been met, then
the current position indicator light will turn off
and the selected position indicator light will
flash until the transfer case completes the
shift. When the shift is complete, the position
indicator light for the selected position will
stop flashing and remain on.
ACTIVE-LEVEL FOUR CORNER AIR
SUSPENSION SYSTEM — IF EQUIPPED
DESCRIPTION
The air suspension system provides full time
load leveling capability along with the benefit of
being able to adjust vehicle height by using the
toggle switch.
Air Suspension Switch

Normal Ride Height (NRH)
– This is the stan-
dard position of the suspension and is meant
for normal driving.

Off-Road 1 (OR1) (Raises the vehicle
approximately 1 inch (26 mm)) – This posi-
tion should be the primary position for all
off-road driving until Off-Road 2 (OR2) is
needed. A smoother and more comfortable
ride will result. To enter OR1, push the

WARNING!
Always engage the parking brake when
powering down the vehicle if the “SVC 4WD
Warning Light” is illuminated. Not engaging
the parking brake may allow the vehicle to roll
which may cause personal injury or death.
1 — Off-Road 2 Indicator (Customer Selectable)
2 — Off-Road 1 Indicator (Customer Selectable)
3 — Normal Ride Height Indicator (Customer Se -
lectable)
4 — Aero Mode Indicator (Customer Selectable)
5 — Entry/Exit Mode Indicator (Customer Select -
able)
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174STARTING AND OPERATING
LIMITED-SLIP DIFFERENTIAL — IF
EQUIPPED
The limited-slip differential provides additional
traction on snow, ice, mud, sand and gravel,
particularly when there is a difference between
the traction characteristics of the surface under
the right and left rear wheels. During normal
driving and cornering, the limited-slip unit
performs similarly to a conventional differential.
On slippery surfaces, however, the differential
delivers more of the driving effort to the rear
wheel having the better traction.
The limited-slip differential is especially helpful
during slippery driving conditions. With both
rear wheels on a slippery surface, a slight
application of the accelerator will supply
maximum traction. When starting with only one
rear wheel on an excessively slippery surface,
slight momentary application of the parking
brake may be necessary to gain maximum
traction. Care should be taken to avoid sudden
accelerations when both rear wheels are on a
slippery surface. This could cause both rear
wheels to spin, and allow the vehicle to slide
sideways on the crowned surface of a road or in
a turn.
POWER STEERING
ELECTRIC POWER STEERING
The electric power steering system will provide
increased vehicle response and ease of
maneuverability. The power steering system
adapts to different driving conditions.
If the steering icon is flashing, it indicates that
the vehicle needs to be taken to the dealer for
service. It is likely the vehicle has lost power
steering assistance.If the steering icon is displayed and the “POWER
STEERING SYSTEM OVER TEMP” message is
displayed on the instrument cluster screen, this
indicates an over temperature condition in the
power steering system. Once driving conditions
are safe, pull over and let the vehicle idle for a
few moments until the icon and message turn
off Ú
page 114.
If the steering icon is displayed and the
“SERVICE POWER STEERING – ASSIST OFF”
message is displayed the instrument cluster
screen, this indicates the vehicle needs to be
taken to the dealer for service Ú page 114.
NOTE:
Even if the power steering assistance is no
longer operational, it is still possible to steer
the vehicle. Under these conditions there will
be a substantial increase in steering effort,
especially at low speeds and during parking
maneuvers.
If the condition persists, see an authorized
dealer for service.
WARNING!
When servicing vehicles equipped with a
limited-slip or locking differential never run
the engine with one rear wheel off the ground
since the vehicle may drive through the rear
wheel remaining on the ground and result in
unintended movement.

21_DT_OM_EN_USC_t.book Page 174

STARTING AND OPERATING175
FUEL SAVER TECHNOLOGY 5.7L ENGINES
ONLY — IF EQUIPPED
This feature offers improved fuel economy by
shutting off four of the engine's eight cylinders
during light load and cruise conditions. The
system is automatic with no driver inputs or
additional driving skills required.
NOTE:
This system may take some time to return to full
functionality after a battery disconnect.
STOP/START SYSTEM — IF EQUIPPED
The Stop/Start function is developed to save
fuel and reduce emissions. The system will stop
the engine automatically during a vehicle stop if
the required conditions are met. Releasing the
brake pedal or shifting out of DRIVE will
automatically restart the engine.
Vehicles equipped with eTorque contain a
heavy duty motor generator and an additional
hybrid electric battery to store energy from
vehicle deceleration for use on engine startup
after a stop as well as providing launch torque
assist.
AUTOSTOP MODE

The Stop/Start feature is enabled after every
normal customer engine start. It will remain in
STOP/START NOT READY until you drive
forward with a vehicle speed greater than
2 mph (3 km/h). At that time, the system will
go into STOP/START READY.

To Activate The Autostop Mode, The Following
Must Occur:

1. The system must be in STOP/START READY
state. A STOP/START READY message will
be displayed in the instrument cluster
within the Stop/Start section
Ú
page 114.

2. The vehicle must be completely stopped.
3. The transmission gear selector must be in DRIVE and the brake pedal pressed.
The engine will shut down, the tachometer will
move to the zero position and the stop/start
telltale will illuminate indicating you are in an
Autostop. While in an Autostop, the Climate
Controls system may automatically adjust
airflow to maintain cabin comfort. Customer
settings will be maintained upon return to an
engine running condition.
POSSIBLE REASONS THE ENGINE DOES
N
OT AUTOSTOP
Prior to engine shut down, the system will check
many safety and comfort conditions to see if
they are fulfilled. In following situations, the
engine will not Autostop:
Driver’s seat belt is not buckled
Driver’s door is not closed
The vehicle is on a steep grade
Cabin heating or cooling is in process and an
acceptable cabin temperature has not been
achieved
HVAC is set to full defrost mode at a high
blower speed
Engine has not reached normal operating
temperature
Engine temperature too high
The battery is charging
The transmission is not in DRIVE
Hood is open
Transfer case is in 4WD LOW
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176STARTING AND OPERATING
TOW/HAUL mode is selected
Accelerator pedal input
Excessive 12 Volt loads
It may be possible to operate the vehicle several
consecutive times in extreme conditions and
not meet all criteria to enable an Autostop state.
TO START THE ENGINE WHILE IN
A
UTOSTOP MODE
While in DRIVE, the engine will start when the
brake pedal is released or the throttle pedal is
pressed and the transmission will automatically
reengage upon engine restart.
Conditions That Will Cause The Engine To Start
Automatically While In Autostop Mode
The engine will start automatically when:
The transmission selector is moved from
DRIVE to REVERSE, NEUTRAL, or PARK
To maintain cabin temperature near the
HVAC settings
HVAC is set to full defrost mode
12 Volt demand requires engine restart
Stop/Start OFF switch is pushed
Transfer case is in 4WD LOW
The emissions system override is present
A Stop/Start system error present
Conditions That Force An Automatic Shift To
Park While In Autostop Mode
The engine will not start automatically and the
transmission will be placed in PARK if:
The driver door is open and brake pedal
released
The driver door is open and the driver seat
belt is unbuckled
The engine hood has been opened
A Stop/Start system error present
The engine may then be restarted by moving the
transmission shift selector out of PARK (e.g. to
DRIVE) or, in some cases, only by a KEY START.
The instrument cluster will display a SHIFT OUT
OF PARK message, or a STOP/START KEY
START REQUIRED message, to indicate which
action is required Ú page 114.
TO MANUALLY TURN OFF THE STOP
S
TART SYSTEM

Stop/Start OFF Switch

Push the Stop/Start OFF switch (located on the
switch bank). The light on the switch will
illuminate. The “STOP/START OFF” message
will appear in the instrument cluster display and
the autostop mode will be disabled
Ú page 114.
NOTE:
The Stop/Start system will reset itself back to
the ON mode every time the ignition is turned
OFF and back ON.

21_DT_OM_EN_USC_t.book Page 176

STARTING AND OPERATING179
(Continued)
To Resume Speed
To resume a previously set speed, push the RES
button and release. Resume can be used at any
speed above 20 mph (32 km/h).
To Deactivate
A tap on the brake pedal, pushing the CANC
(cancel) button, or normal brake pressure while
slowing the vehicle will deactivate the Cruise
Control system without erasing the set speed
from memory.
The following conditions will also deactivate the
Cruise Control system without erasing the set
speed from memory:
Vehicle parking brake is applied
Stability event occurs
Gear selector is moved out of DRIVE
Engine overspeed occurs
Pushing the on/off button or placing the ignition
in the OFF position, erases the set speed from
memory.
ADAPTIVE CRUISE CONTROL (ACC) — IF
E
QUIPPED
Adaptive Cruise Control (ACC) increases the
driving convenience provided by Cruise Control
while traveling on highways and major
roadways. However, it is not a safety system
and not designed to prevent collisions. The
Cruise Control function performs differently
Ú page 177.
ACC will allow you to keep Cruise Control
engaged in light to moderate traffic conditions
without the constant need to reset your speed.
ACC utilizes a radar sensor and a forward facing
camera designed to detect a vehicle directly
ahead of you to maintain a set speed.
NOTE:
If the ACC sensor detects a vehicle ahead,
ACC will apply limited braking or acceleration
(not to exceed the original set speed) auto -
matically to maintain a preset following
distance, while matching the speed of the
vehicle ahead.
Any chassis/suspension or tire size modifica -
tions to the vehicle will affect the perfor -
mance of the Adaptive Cruise Control and
Forward Collision Warning system.
Fixed Speed Cruise Control alone (an ACC
distance not set) will not detect vehicles
directly ahead of you. Always be aware of the
mode selected.
WARNING!
Adaptive Cruise Control (ACC) is a conve -
nience system. It is not a substitute for
active driver involvement. It is always the
driver’s responsibility to be attentive of
road, traffic, and weather conditions,
vehicle speed, distance to the vehicle
ahead; and, most importantly, brake opera -
tion to ensure safe operation of the vehicle
under all road conditions. Your complete
attention is always required while driving to
maintain safe control of your vehicle.
Failure to follow these warnings can result
in a collision and death or serious personal
injury.
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184STARTING AND OPERATING
When An ACC Distance Is Also Set:
When you use the SET (-) button to decel -
erate, if the engine’s braking power does not
slow the vehicle sufficiently to reach the set
speed, the brake system will automatically
slow the vehicle.
The ACC system decelerates the vehicle to a
full stop when following the vehicle in front. If
your vehicle follows the vehicle in front to a
standstill, after two seconds the driver will
either have to push the RES (resume) button,
or apply the accelerator pedal to reengage
the ACC to the existing set speed.
The ACC system maintains set speed when
driving uphill and downhill. However, a slight
speed change on moderate hills is normal. In
addition, downshifting may occur while
climbing uphill or descending downhill. This
is normal operation and necessary to main -
tain set speed. When driving uphill and down -
hill, the ACC system will cancel if the braking
temperature exceeds normal range (over -
heated).
Setting The Following Distance In ACC
The specified following distance for Adaptive
Cruise Control (ACC) can be set by varying the
distance setting between four bars (longest),
three bars (long), two bars (medium) and one
bar (short). Using this distance setting and the
vehicle speed, ACC calculates and sets the
distance to the vehicle ahead. This distance
setting displays in the instrument cluster
display.

Distance Settings
To increase the distance setting, push the
Distance Increase button and release. Each
time the button is pushed, the distance setting
increases by one bar (longer).
To decrease the distance setting, push the
Distance Decrease button and release. Each
time the button is pushed, the distance setting
decreases by one bar (shorter).
If there is no vehicle ahead, the vehicle will
maintain the set speed. If a slower moving
vehicle is detected in the same lane, the
instrument cluster displays the ACC Set With
Target Detected Indicator Light, and the system
adjusts vehicle speed automatically to maintain
the distance setting, regardless of the set
speed.
The vehicle will then maintain the set distance
until:
The vehicle ahead accelerates to a speed
above the set speed.
The vehicle ahead moves out of your lane or
view of the sensor.
The distance setting is changed.
The system disengages.
1 — Longest Distance Setting (Four Bars)
2 — Long Distance Setting (Three Bars)
3 — Medium Distance Setting (Two Bars)
4 — Short Distance Setting (One Bar)

21_DT_OM_EN_USC_t.book Page 184

STARTING AND OPERATING185
The maximum braking applied by ACC is limited;
however, the driver can always apply the brakes
manually, if necessary.
NOTE:
The brake lights will illuminate whenever the
ACC system applies the brakes.
A Proximity Warning will alert the driver if ACC
predicts that its maximum braking level is not
sufficient to maintain the set distance. If this
occurs, a visual alert “BRAKE” will flash in the
instrument cluster display and a chime will
sound while ACC continues to apply its
maximum braking capacity.
NOTE:
The “BRAKE!” Screen in the instrument cluster
display is a warning for the driver to take action
and does not necessarily mean that the
Forward Collision Warning system is applying
the brakes autonomously.
Overtake Aid
When driving with Adaptive Cruise Control (ACC)
engaged, and following a vehicle, the system
will provide an additional acceleration up to the
ACC set speed to assist in passing the vehicle. This additional acceleration is triggered when
the driver utilizes the left turn signal and will
only be active when passing on the left hand
side.
ACC Operation At Stop
If the ACC system brings your vehicle to a
standstill while following the vehicle in front,
your vehicle will resume motion without any
diver intervention if the vehicle in front starts
moving within two seconds.
If the vehicle in front does not start moving
within two seconds of your vehicle coming to a
standstill, the driver will either have to push the
RES (resume) button, or apply the accelerator
pedal to reengage the ACC to the existing set
speed.
NOTE:
After the ACC system holds your vehicle at a
standstill for approximately three consecutive
minutes, the parking brake will be activated,
and the ACC system will be cancelled.
While ACC is holding your vehicle at a standstill,
if the driver seat belt is unbuckled or the driver
door is opened, the parking brake will be
activated, and the ACC system will be cancelled.
Display Warnings And Maintenance
“Wipe Front Radar Sensor In Front Of Vehicle”
Warning
The “ACC/FCW Unavailable Wipe Front Radar
Sensor” warning will display and also a chime
will indicate when conditions temporarily limit
system performance.
This most often occurs at times of poor visibility,
such as in snow or heavy rain. The ACC system
may also become temporarily blinded due to
obstructions, such as mud, dirt or ice. In these
cases, the instrument cluster display will display
“ACC/FCW Unavailable Wipe Front Radar
Sensor” and the system will deactivate.
The “ACC/FCW Unavailable Wipe Front Radar
Sensor” message can sometimes be displayed
while driving in highly reflective areas (i.e. ice
WARNING!
When the ACC system is resumed, the driver
must ensure that there are no pedestrians,
vehicles or objects in the path of the vehicle.
Failure to follow these warnings can result in
a collision and death or serious personal
injury.
4

21_DT_OM_EN_USC_t.book Page 185

STARTING AND OPERATING221
(Continued)
NOTE:
Trailers may look different during day and night
conditions. In such cases, the trailer may need
to recalibrate.
Some trailers (such as boat trailers) will need to
recalibrate while loaded and unloaded.
NOTE:
The system may not detect a trailer in low
light conditions. In sunny conditions, the
performance may be degraded as shadows
pass over the trailer.
The driver is always responsible for safe oper -
ation of truck and trailer.
The driver is always in control of the truck as
well as the trailer and is responsible for
controlling the throttle and brakes.
The system may not function when the
camera lens is blocked, blurred (covered with
water, snow, ice, dirt, etc) and will not work
unless the tailgate is upright and fully
latched.
TOWING REQUIREMENTS
To promote proper break-in of your new vehicle
drivetrain components, the following guidelines
are recommended.
Perform the maintenance listed in the
Scheduled Servicing section for the proper
maintenance intervals Ú page 395. When
towing a trailer, never exceed the GAWR or
GCWR ratings.
CAUTION!
Do not tow a trailer at all during the first
500 miles (805 km) the new vehicle is driven. The engine, axle or other parts could
be damaged.
Then, during the first 500 miles (805 km) that a trailer is towed, do not drive over
50 mph (80 km/h) and do not make starts
at full throttle. This helps the engine and
other parts of the vehicle wear in at the
heavier loads.
WARNING!
Make certain that the load is secured in the
trailer and will not shift during travel. When
trailering cargo that is not fully secured,
dynamic load shifts can occur that may be
difficult for the driver to control. You could
lose control of your vehicle and have a colli -
sion.
When hauling cargo or towing a trailer, do
not overload your vehicle or trailer. Over -
loading can cause a loss of control, poor
performance or damage to brakes, axle,
engine, transmission, steering, suspension,
chassis structure or tires.
Safety chains must always be used
between your vehicle and trailer. Always
connect the chains to the hook retainers of
the vehicle hitch. Cross the chains under
the trailer tongue and allow enough slack
for turning corners.
4

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