2021 RAM CHASSIS CAB warning

172STARTING AND OPERATING
To adjust the distance setting, push the
Distance Button and release. Each time the
button is pushed, the distance setting increases
by one bar (longer). When the farthest distance
is set, pushing the distance button again will
reset to the shortest distance.

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. 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 wil l alert the driver if ACC
predicts that its maximum braking level is not
sufficient to maintain the set distance. If this
occurs, a visua l alert “BRAKE” will flash in the
instrument cluster display and a chime will
sound while ACC continues to apply its
maximum braking force.
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 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
driver intervention if the vehicle in front starts
moving within two seconds.

21_DPF_OM_EN_USC_t.book Page 172
Trailer Detect — If Equipped
When a trailer is detected, the ACC system
automatically defaults to the longest setting
(four bars). The setting can be overridden by
pushing the Distance Button on the steering
wheel.

STARTING AND OPERATING173 If the vehicle in front does not start moving
within two seconds of your vehicle coming to a
standstill, the ACC with Stop system will
cancel and the brakes will release. A cancel
message will display on the instrument cluster
display and produce a warning chime. The
driver must now manually operate the
vehicle's accelerator and brakes.
While ACC is holding your vehicle at a
standstill, if the driver seat belt is unbuckled
or the driver door is opened, the ACC system
will cancel and the brakes will release. Driver
intervention will be required at this moment.
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 a chime will
sound 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.

This message can sometimes be displayed while
driving in highly reflective areas (i.e. ice 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 or
aftermarket grilles. Doing so could cause an
ACC system failure or malfunction.
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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21_DPF_OM_EN_USC_t.book Page 173

174STARTING AND OPERATING
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 a
chime will sound 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. If weather conditions are not a factor, the driver
should examine the windshield and the camera
located on the back side of the inside rearview
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.

21_DPF_OM_EN_USC_t.book Page 174

STARTING AND OPERATING175
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

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STARTING AND OPERATING177
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
Stationary Objects And Vehicles

ACC does not react to stationary objects and
stationary vehicles. For example, ACC will not react
in situations where the vehicle you are following
exits your lane and the vehicle ahead is stopped in
your lane. Always be attentive and ready to apply the
brakes if necessary
Ú

page 449.

Stationary Object And Stationary Vehicle Example
PARKSENSE FRONT/REAR PARK ASSIST —
IF EQUIPPED

The ParkSense Park Assist system provides visual
and audible indications of the distance between the
rear, and/or front fascia/bumper, and a detected
obstacle when backing up or moving forward (e.g.
during a parking maneuver). For limitations of this
system and recommendations, see
Ú
page 182.

ParkSense will retain the system state (enabled
or disabled) from the previous ignition cycle
when the ignition is placed in the ON/RUN
position.
ParkSense can be active only when the gear
selector is in REVERSE or DRIVE. If ParkSense is
enabled at one of these gear selector positions,
the system will remain active until the vehicle
speed is increased to approximately 7 mph
(11 km/h) or above. A warning will appear in the
instrument cluster display when the vehicle is
in REVERSE, indicating the vehicle is above
ParkSense operating speed. The system will
become active again if the vehicle speed is
decreased to speeds less than approximately
6 mph (9 km/h).
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21_DPF_OM_EN_USC_t.book Page 177

178STARTING AND OPERATING
PARKSENSE SENSORS
For the 3500, 4500 and 5500 Chassis Cab
vehicles, the rear ParkSense sensors are
shipped loose. Please refer to the Ram Body
Builders Guide for more information.
The four ParkSense sensors are to be located in
the rear fascia/bumper, and monitor the area
behind the vehicle that is within the sensors’
field of view.
The sensors can detect obstacles from
approximately 12 inches (30 cm) up to
79 inches (200 cm) from the rear fascia/
bumper in the horizontal direction, depending
on the location, type and orientation of the
obstacle.
NOTE:
If equipped as a dually, the ParkSense system
has six rear sensors to assist in detection
around the dually flares.
The six ParkSense sensors, located in the front
fascia/bumper, monitor the area in front of the
vehicle that is within the sensors’ field of view.
The sensors can detect obstacles from
approximately 12 inches (30 cm) up to 47 inches
(120 cm) from the front fascia/bumper in the
horizontal direction, depending on the location,
type and orientation of the obstacle.

PARKSENSE WARNING DISPLAY

The ParkSense Warning screen is located within
the instrument cluster display

Ú
page 90. It
provides visual warnings to indicate the distance
between the rear fascia/bumper and/or front
fascia/bumper and the detected obstacle.

PARKSENSE DISPLAY
The warning display will turn on indicating the
system status when the vehicle is in REVERSE
or when the vehicle is in DRIVE and an obstacle
has been detected.
The system will indicate a detected obstacle by
showing a single arc in the left and/or right rear
regions based on the obstacle’s distance and
location relative to the vehicle.

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180STARTING AND OPERATING
If an obstacle is detected in the left and/or right rear region, the display will show a single arc in the left and/or right rear region and the system will
produce a tone. As the vehicle moves closer to the obstacle, the display will show the single arc moving closer to the vehicle and the tone will change
from a single 1/2 second tone to slow, to fast, to continuous.
The vehicle is close to the obstacle when the display shows one flashing arc and sounds a continuous tone. The following chart shows the warning alert
operation when the system is detecting an obstacle:
WARNING ALERTS FOR REAR
Rear Distance
(inches/cm) Greater than
79 inches (200 cm) 79-59 inches
(200-150 cm) 59-47 inches
(150-120 cm) 47-39 inches
(120-100 cm) 39-25 inches
(100-65 cm) 25-12 inches
(65-30 cm) Less than
12 inches (30 cm)
Audible Alert Chime NoneSingle 1/2
Second Tone Slow
Slow FastFast Continuous
Arcs-Left None NoneNoneNoneNone 6th Flashing 5th Flashing
Arcs-Center None 10th Solid 9th Solid 8th Solid 7th Flashing 6th Flashing 5th Flashing Arcs-Right None NoneNoneNoneNone 6th Flashing 5th Flashing
Radio Volume Reduced No
Yes YesYesYesYesYes

21_DPF_OM_EN_USC_t.book Page 180

STARTING AND OPERATING181
NOTE:
ParkSense will reduce the volume of the radio,
if on, when the system is sounding an audio
tone.
Front Park Assist Audible Alerts
ParkSense will turn off the Front Park Assist
audible alert (chime) after approximately three
seconds when an obstacle has been detected,
the vehicle is stationary, and brake pedal is
applied. Adjustable Chime Volume Settings
The Front and Rear chime volume settings are
programmable through the Uconnect system
Ú
page 228.
ENABLING AND DISABLING PARKSENSE
Front ParkSense can be enabled and
disabled with the Front ParkSense
switch.
Rear ParkSense can be enabled and disabled
with the Rear ParkSense switch.
When the gear selector is moved to REVERSE
and the Front or Rear system is disabled, the
instrument cluster display will show a vehicle graphic with an “Off” message overlay over the
system that is off (Front or Rear system). This
vehicle graphic will be displayed for as long as
the vehicle is in REVERSE.
The Front or Rear ParkSense switch LED will be
on when Front or Rear ParkSense is disabled or
requires service. The Front or Rear ParkSense
switch LED will be off when the Front or Rear
system is enabled. If the Front or Rear
ParkSense switch is pushed, and the system
requires service, the Front or Rear ParkSense
switch LED will blink momentarily, and then the
LED will be on.
WARNING ALERTS FOR FRONT
Front Distance
(inches/cm) Greater than 47 inches
(120 cm) 47-39 inches
(120-100 cm) 39-25 inches
(100-65 cm) 25-12 inches
(65-30 cm) Less than 12 inches
(30 cm)
Audible Alert Chime NoneNoneNone FastContinuous
Arcs-Left NoneNoneNone3rd Flashing 4th Flashing
Arcs-Center None1st Solid2nd Flashing 3rd Flashing4th Flashing
Arcs-Right NoneNoneNone3rd Flashing 4th Flashing
Radio Volume Reduced No
NoNo Yes Yes
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