RAM 1500 2021 Owners Manual

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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180STARTING AND OPERATING
(Continued)
Adaptive Cruise Control (ACC) Operation
The buttons on the right side of the steering
wheel operate the Adaptive Cruise Control
system.
Adaptive Cruise Control Buttons

Adaptive Cruise Control (ACC) Menu
The instrument cluster display will show the
current ACC system settings. The information it
displays depends on ACC system status.
Push the Adaptive Cruise Control (ACC) on/off
button until one of the following appears in the
instrument cluster display:
Adaptive Cruise Control Off
When ACC is deactivated, the display will read
“Adaptive Cruise Control Off.”
The ACC system:
Does not react to pedestrians,
oncoming vehicles, and stationary
objects (e.g., a stopped vehicle in a
traffic jam or a disabled vehicle).
Cannot take street, traffic, and weather
conditions into account, and may be
limited upon adverse sight distance
conditions.
Does not always fully recognize
complex driving conditions, which can
result in wrong or missing distance
warnings.
Will bring your vehicle to a complete
stop while following a vehicle ahead
and hold your vehicle for approximately
three minutes in the stop position. If the
vehicle ahead does not start moving
within three minutes the parking brake
will be activated, and the ACC system
will be cancelled.
WARNING!
(Continued)
You should switch off the ACC system:
When driving in fog, heavy rain, heavy
snow, sleet, heavy traffic, and complex
driving situations (i.e., in highway construc -
tion zones).
When entering a turn lane or highway off
ramp; when driving on roads that are
winding, icy, snow-covered, slippery, or
have steep uphill or downhill slopes.
When towing a trailer up or down steep
slopes.
When circumstances do not allow safe
driving at a constant speed.
WARNING! (Continued)
1 — Distance Setting Increase
2 — Adaptive Cruise Control (ACC) On/Off
3 — Distance Setting Decrease

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STARTING AND OPERATING181
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.”
Adaptive Cruise Control Set
When the SET (+) or the SET (-) button is
pushed, the display will read “ACC SET.”
When ACC is set, the set speed will show in the
instrument cluster display.
The ACC screen may display once again if any of
the following ACC activity occurs:
System Cancel
Driver Override
System Off
ACC Proximity Warning
ACC Unavailable Warning
The instrument cluster display will return to the
last display selected after five seconds of no
ACC display activity.
Activating Adaptive Cruise Control (ACC)
The minimum set speed for the ACC system is
20 mph (32 km/h).
When the system is turned on and in the ready
state, the instrument cluster display will read
“ACC Ready.”
When the system is off, the instrument cluster
display will read “Adaptive Cruise Control (ACC)
Off.”
NOTE:
You cannot engage ACC under the following
conditions:
When in 4WD Low
When the brakes are applied
When the parking brake is applied
When the automatic transmission is in PARK,
REVERSE or NEUTRAL
When the vehicle speed is below the
minimum speed range
When the brakes are overheated
When the driver’s door is open at low speeds
When the driver’s seat belt is unbuckled at
low speeds
When there is a stationary vehicle in front of
your vehicle in close proximity
ESC Full Off mode is active
To Activate/Deactivate
Push and release the Adaptive Cruise Control
(ACC) on/off button. The ACC menu in the
instrument cluster displays “ACC Ready.”
To turn the system off, push and release the
Adaptive Cruise Control (ACC) on/off button
again. At this time, the system will turn off and
the instrument cluster display will show
“Adaptive Cruise Control (ACC) Off.”
WARNING!
Leaving the Adaptive Cruise Control (ACC)
system on when not in use is dangerous. You
could accidentally set the system or cause it
to go faster than you want. You could lose
control and have a collision. Always leave the
system off when you are not using it.
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182STARTING AND OPERATING
To Set A Desired ACC Speed
When the vehicle reaches the speed desired,
push the SET (+) button or the SET (-) button
and release. The instrument cluster display will
show the set speed.
NOTE:
Fixed Speed Cruise Control can be used without
an ACC distance set. To change between the
different modes, push the ACC on/off button
which turns the ACC and the Fixed Speed Cruise
Control off. Pushing the Fixed Speed Cruise
Control on/off button will result in turning on
(changing to) Fixed Speed Cruise Control mode. If ACC is set when the vehicle speed is
below
20 mph (32 km/h), the set speed will default to
20 mph (20 km/h).
NOTE:
Fixed Speed Cruise Control cannot be set below
20 mph (32 km/h).
If either system is set when the vehicle speed is
above 20 mph (32 km/h), the set speed shall
be the current speed of the vehicle.
NOTE:
Keeping your foot on the accelerator pedal
can cause the vehicle to continue to accel -
erate beyond the set speed. If this occurs, the
message “ACC DRIVER OVERRIDE” will
display in the instrument cluster display.
If you continue to accelerate beyond the set
speed while an ACC distance is also set, the
system will not be controlling the distance
between your vehicle and the vehicle ahead.
The vehicle speed will only be determined by
the position of the accelerator pedal.
To Cancel
The following conditions cancel the ACC or Fixed
Speed Cruise Control systems:
The brake pedal is applied
The CANC (cancel) button is pushed
The Anti-Lock Brake system (ABS) activates
The trailer brake is applied manually (if
equipped)
The gear selector is removed from the DRIVE
position
The Electronic Stability Control/Traction
Control System (ESC/TCS) activates
The vehicle parking brake is applied
The Trailer Sway Control (TSC) activates
The driver switches ESC to Full Off mode
The braking temperature exceeds normal
range (overheated)
The following conditions will only cancel the ACC
system:
Driver seat belt is unbuckled at low speeds
Driver door is opened at low speeds
WARNING!
In the Fixed Speed Cruise Control mode, the
system will not react to vehicles ahead. In
addition, the proximity warning does not
activate and no alarm will sound even if you
are too close to the vehicle ahead since
neither the presence of the vehicle ahead nor
the vehicle-to-vehicle distance is detected. Be
sure to maintain a safe distance between
your vehicle and the vehicle ahead. Always be
aware which mode is selected.

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STARTING AND OPERATING183
To Turn Off
The system will turn off and clear the set speed
in memory if:
The Adaptive Cruise Control (ACC) on/off
button is pushed
The Fixed Speed Cruise Control on/off button
is pushed
The ignition is placed in the OFF position
4WD Low is engaged
To Resume
If there is a set speed in memory, push the RES
(resume) button and then remove your foot
from the accelerator pedal. The instrument
cluster display will display the last set speed.
Resume can be used at any speed above
20 mph (32 km/h) when only Fixed Speed
Cruise Control is being used.
Resume can be used at any speed above 0 mph
(0 km/h) when ACC is active. NOTE:
While in ACC mode when the vehicle comes
to a complete stop longer than two seconds,
the system will cancel. The driver will have to
apply the brakes to keep the vehicle at a
standstill.
ACC cannot be resumed if there is a
stationary vehicle in front of your vehicle in
close proximity.
To Vary The Speed Setting
To Increase Or Decrease The Set Speed
After setting a speed, you can increase the set
speed by pushing the SET
(+) button, or
decrease speed by pushing the SET (-) button. U.S. Speed (mph)
Pushing the SET
(+), or SET (-) button once
will result in a 1 mph speed adjustment. Each
subsequent tap of the button results in an
adjustment of 1 mph.
If the button is continually pushed, the set
speed will continue to adjust in 5 mph incre -
ments until the button is released. The new
set speed is reflected in the instrument
cluster display.
Metric Speed (km/h)
Pushing the SET (+), or SET (-) button once
will result in a 1 km/h speed adjustment.
Each subsequent tap of the button results in
an adjustment of 1 km/h.
If the button is continually pushed, the set
speed will continue to adjust in 10 km/h
increments until the button is released. The
new set speed is reflected in the instrument
cluster display.
NOTE:
When you override and push the SET (+) button
or SET (-) buttons, the new set speed will be the
current speed of the vehicle.
WARNING!
The Resume function should only be used if
traffic and road conditions permit. Resuming
a set speed that is too high or too low for
prevailing traffic and road conditions could
cause the vehicle to accelerate or decelerate
too sharply for safe operation. 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)

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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.
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186STARTING AND OPERATING
and snow, or tunnels with reflective tiles). The
ACC system will recover after the vehicle has left
these areas. Under rare conditions, when the
radar is not tracking any vehicles or objects in
its path this warning may temporarily occur.
NOTE:
If the “ACC/FCW Unavailable Wipe Front Radar
Sensor” warning is active, Fixed Speed Cruise
Control is still available.
If weather conditions are not a factor, the driver
should examine the sensor. It may require
cleaning or removal of an obstruction. The
sensor is located in the camera in the center of
the windshield, on the forward side of the
rearview mirror.
To keep the ACC system operating properly, it is
important to note the following maintenance
items:
Always keep the sensor clean. Carefully clear
the windshield.
Do not remove any screws from the sensor.
Doing so could cause an ACC system
malfunction or failure and require a sensor
realignment.
Do not attach or install any accessories near
the sensor, including transparent material.
Doing so could cause an ACC system failure
or malfunction.
When the condition that deactivated the system
is no longer present, the system will return to
the “Adaptive Cruise Control Off” state and will
resume function by simply reactivating it.
NOTE:
If the “ACC/FCW Unavailable Wipe Front
Radar Sensor” message occurs frequently
(e.g. more than once on every trip) without
any snow, rain, mud, or other obstruction,
have the radar sensor realigned at an autho -
rized dealer.
Installing a snow plow, front-end protector,
an aftermarket grille or modifying the grille is
not recommended. Doing so may block the
sensor and inhibit ACC/FCW operation. “Clean Front Windshield” Warning
The “ACC/FCW Limited Functionality Clean
Front Windshield” 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 and fog. The ACC
system may also become temporarily blinded
due to obstructions, such as mud, dirt, or ice on
windshield, driving directly into the sun and fog
on the inside of glass. In these cases, the
instrument cluster display will show “ACC/FCW
Limited Functionality Clean Front Windshield”
and the system will have degraded
performance.
This message can sometimes be displayed
while driving in adverse weather conditions. The
ACC/FCW system will recover after the vehicle
has left these areas. Under rare conditions,
when the camera is not tracking any vehicles or
objects in its path this warning may temporarily
occur.

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STARTING AND OPERATING187
If weather conditions are not a factor, the driver
should examine the windshield and the camera
located on the back side of the inside rear view
mirror. They may require cleaning or removal of
an obstruction.
When the condition that created limited
functionality is no longer present, the system
will return to full functionality.
NOTE:
If the “ACC/FCW Limited Functionality Clean
Front Windshield” message occurs frequently
(e.g. more than once on every trip) without any
snow, rain, mud, or other obstruction, have the
windshield and forward facing camera
inspected at an authorized dealer.
Service ACC/FCW Warning
If the system turns off, and the instrument
cluster displays “ACC/FCW Unavailable Service
Required” or “Cruise/FCW Unavailable Service
Required”, there may be an internal system
fault or a temporary malfunction that limits ACC
functionality. Although the vehicle is still
drivable under normal conditions, ACC will be
temporarily unavailable. If this occurs, try
activating ACC again later, following an ignition
cycle. If the problem persists, see an authorized
dealer.Precautions While Driving With ACC
NOTE:
Aftermarket add-ons such as snow plows, lift
kits, and brush/grille bars can hinder module
performance. Ensure the radar/camera has
no obstructions in the field of view.
Height modifications can limit module perfor -
mance and functionality.
Do not put stickers or easy passes over the
camera/radar field of view.
Any modifications to the vehicle that may
obstruct the field of view of the radar/camera
are not recommended.
In certain driving situations, ACC may have
detection issues. In these cases, ACC may
brake late or unexpectedly. The driver needs to
stay alert and may need to intervene. The
following are examples of these types of
situations:
Towing A Trailer
ACC while towing a trailer is recommended only
with an Integrated Trailer Brake Controller.
Aftermarket trailer brake controllers will not
activate the trailer brakes when ACC is braking. Offset Driving
ACC may not detect a vehicle in the same lane
that is offset from your direct line of travel, or a
vehicle merging in from a side lane. There may
not be sufficient distance to the vehicle ahead.
The offset vehicle may move in and out of the
line of travel, which can cause your vehicle to
brake or accelerate unexpectedly.

Offset Driving Condition Example

Turns And Bends
When driving on a curve with ACC engaged, the
system may decrease the vehicle speed and
acceleration for stability reasons, with no
vehicle in front detected. Once the vehicle is out
of the curve the system will resume your original
set speed. This is a part of normal ACC system
functionality.
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188STARTING AND OPERATING
NOTE:
On tight turns ACC performance may be limited.

Turn Or Bend Example

Using ACC On Hills
When driving on hills, ACC may not detect a
vehicle in your lane. Depending on the speed,
vehicle load, traffic conditions, and the
steepness of the hills, ACC performance may be
limited.
ACC Hill Example

Lane Changing
ACC may not detect a vehicle until it is
completely in the lane in which you are
traveling. In the lane changing example below,
ACC has not yet detected the vehicle changing
lanes and it may not detect the vehicle until it's
too late for the ACC system to take action. ACC
may not detect a vehicle until it is completely in
the lane. There may not be sufficient distance to
the lane-changing vehicle. Always be attentive
and ready to apply the brakes if necessary.
Lane Changing Example

Narrow Vehicles
Some narrow vehicles traveling near the outer
edges of the lane or edging into the lane are not
detected until they have moved fully into the
lane. There may not be sufficient distance to the
vehicle ahead.

Narrow Vehicle Example

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