2021 RAM CHASSIS CAB sensor

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

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.

21_DPF_OM_EN_USC_t.book Page 178

182STARTING AND OPERATING
SERVICE THE PARKSENSE PARK ASSIST
S
YSTEM
During vehicle start up, when the Front/Rear
ParkSense System has detected a faulted
condition, the instrument cluster display will
show the "Front/Rear ParkSense Unavailable
Service Required" or the "Front/Rear
ParkSense Unavailable Wipe Sensors"
message.
When the gear selector is moved into REVERSE,
a vehicle graphic will show in the instrument
cluster display, along with the display overlay
“Wipe Sensors.” If the system needs service,
the display overlay will read “Service.” Under
this condition, ParkSense will not operate.
If "Front/Rear ParkSense Unavailable Wipe
Sensors" appears in the instrument cluster
display make sure the outer surface and the
underside of the rear fascia/bumper is clean
and clear of snow, ice, mud, dirt or other
obstruction, and then cycle the ignition. If the
message continues to appear, see an
authorized dealer. If "Front/Rear ParkSense Unavailable Service
Required" appears in the instrument cluster
display, see an authorized dealer.CLEANING THE PARKSENSE SYSTEM
Clean the ParkSense sensors with water, car
wash soap and a soft cloth. Do not use rough or
hard cloths. Do not scratch or poke the sensors.
Otherwise, you could damage the sensors.
PARKSENSE SYSTEM USAGE
P
RECAUTIONS
NOTE:
Ensure that the front and rear bumpers are
free of snow, ice, mud, dirt and debris to keep
the ParkSense system operating properly.

Jackhammers, large trucks, and other vibrations
could affect the performance of ParkSense.
When you move the gear selector to the
REVERSE position and Front or Rear ParkSense
is turned off, the instrument cluster display will
show "Off" on the vehicle graphic arcs. This
vehicle graphic will be displayed for as long as
the vehicle is in REVERSE.

ParkSense, when on, will reduce the volume
of the radio when it is sounding a tone.
Clean the ParkSense sensors regularly,
taking care not to scratch or damage them.
The sensors must not be covered with ice,
snow, slush, mud, dirt or debris. Failure to do
so can result in the system not working prop -
erly. The ParkSense system might not detect
an obstacle behind or in front of the fascia/
bumper, or it could provide a false indication
that an obstacle is behind or in front of the
fascia/bumper.
Use the ParkSense switch to turn the Park -
Sense system off if obstacles such as bicycle
carriers, trailer hitches, etc. are placed within
18 inches (45 cm) from the rear fascia/
bumper. Failure to do so can result in the
system misinterpreting a close obstacle as a
sensor problem, causing the “Front/Rear
ParkSense Unavailable Service Required”
message to be appear in the instrument
cluster display.

21_DPF_OM_EN_USC_t.book Page 182

STARTING AND OPERATING183
LANESENSE — IF EQUIPPED
LANESENSE OPERATION
The LaneSense system is operational at speeds
above 37 mph (60 km/h) and below 112 mph
(180 km/h). It uses a forward looking camera to
detect lane markings and measure vehicle
position within the lane boundaries.
When both lane markings are detected and the
driver drifts out of the lane (no turn signal has
been applied) OR the driver departs the lane on
the opposite side of the applied turn signal (if the left turn signal is applied and the vehicle
departs to the right), the LaneSense system
provides a haptic warning in the form of torque
applied to the steering wheel, as well as a visual
warning in the instrument cluster display to
prompt the driver to remain within the lane
boundaries.
The driver may manually override the haptic
warning by applying torque into the steering
wheel at any time.
When only a single lane marking is detected
and the driver drifts across that lane marking
(no turn signal applied), the LaneSense system
provides a visual warning through the
instrument cluster display to prompt the driver
to remain within the lane.
When only a single lane marking is detected, a
haptic (torque) warning will not be provided.
NOTE:
When operating conditions have been met, the
LaneSense system will monitor if the driver’s
hands are on the steering wheel and provide
an audible and visual warning to the driver if
removed. The system will cancel if the driver
does not return their hands to the wheel.
WARNING!

Drivers must be careful when backing up
even when using ParkSense. Always check
carefully behind your vehicle, look behind
you, and be sure to check for pedestrians,
animals, other vehicles, obstructions, and
blind spots before backing up. You are
responsible for safety and must continue to
pay attention to your surroundings. Failure to
do so can result in serious injury or death.

Before using ParkSense, it is strongly
recommended that the ball mount and
hitch ball assembly be disconnected from
the vehicle when the vehicle is not used for
towing. Failure to do so can result in injury
or damage to vehicles or obstacles
because the hitch ball will be much closer
to the obstacle than the rear fascia when
the vehicle sounds the continuous tone.
Also, the sensors could detect the ball
mount and hitch ball assembly, depending
on its size and shape, giving a false indica
-
tion that an obstacle is behind the vehicle.
CAUTION!

ParkSense is only a parking aid and it is
unable to recognize every obstacle, including
small obstacles. Parking curbs might be
temporarily detected or not detected at all.
Obstacles located above or below the
sensors will not be detected when they are in
close proximity.

The vehicle must be driven slowly when
using ParkSense in order to be able to stop
in time when an obstacle is detected. It is
recommended that the driver looks over
his/her shoulder when using ParkSense.4

21_DPF_OM_EN_USC_t.book Page 183

196STARTING AND OPERATING
LOOSE FUEL FILLER CAP MESSAGE
If the vehicle diagnostic system
determines that the fuel filler cap
is loose, improperly installed, or
damaged, a loose gASCAP indicator
will display in the instrument cluster telltale
display area Ú page 90. Tighten the fuel filler
cap properly and push the RIGHT button to turn
off the message. If the problem continues, the
message will appear the next time the vehicle is
started.
REFUELING THE VEHICLE — DIESEL ENGINE
NOTE:
When the fuel nozzle “clicks” or shuts off, the
fuel tank is full.
Tighten the fuel filler cap until you hear a
“clicking” sound. This is an indication that the
fuel filler cap is properly tightened.
Make sure that the fuel filler cap is tightened
each time the vehicle is refueled.
DIESEL EXHAUST FLUID
Your vehicle is equipped with a Selective
Catalytic Reduction (SCR) system to meet the
very stringent diesel emissions standards
required by the Environmental Protection
Agency.

The purpose of the SCR system is to reduce levels
of NOx (oxides of nitrogen emitted from engines)
that are harmful to our health and the
environment to a near-zero level. A small quantity
of Diesel Exhaust Fluid (DEF) is injected into the
exhaust upstream of a catalyst where, when
vaporized, it converts smog-forming nitrogen
oxides (NOx) into harmless nitrogen (N2) and
water vapor (H2O), two natural components of
the air we breathe. You can operate with the
comfort that your vehicle is contributing to a
cleaner, healthier world environment for this and
generations to come.

System Overview
This vehicle is equipped with a Diesel Exhaust
Fluid (DEF) injection system and a Selective
Catalytic Reduction (SCR) catalyst to meet the
emission requirements.
The DEF injection system consists of the
following components:
DEF tank
DEF pump
DEF injector
Electronically-heated DEF lines
DEF control module
NOx sensors
Temperature sensors
SCR catalyst
UQS Sensor
For system messages and warnings Úpage 90.
CAUTION!
To avoid fuel spillage and overfilling, do not
“top off” the fuel tank after filling.
WARNING!
A fire may result if gasoline is pumped into a
portable container that is inside of a vehicle.
You could be burned. Always place gas
containers on the ground while filling.

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198STARTING AND OPERATING
(Continued)
NOTE:
The DEF gauge may take up to five seconds
to update after adding a gallon or more of
Diesel Exhaust Fluid (DEF) to the DEF tank.
If you have a fault related to the DEF system,
the gauge may not update to the new level.
See an authorized dealer for service.
The DEF gauge may also not immediately
update after a refill if the temperature of the
DEF fluid is below 39°F (4°C). The DEF tank
heater will possibly warm up the DEF fluid
and allow the gauge to update after a period
of run time. Under very cold conditions, it is
possible that the gauge may not reflect the
new fill level for several drives.
At 40°F (4°C) you could see some increase
in the DEF gauge due to the tank thawing.
The gauge and level sensor are working prop-
erly and is just updating with proper thawed
DEF.
Excessive overfilling of the DEF tank can
result in a MIL lamp/fault code and inaccu -
rate level readings. Refilling With Nozzles
You can fill up at any DEF distributor.
Proceed as follows:
Insert the DEF nozzle in the filler, start
refilling and stop refilling at the first shut-off
(the shut-off indicates that the DEF tank is
full). DO NOT proceed with the refilling, to
prevent spillage of DEF.
Extract the nozzle.
Refilling With Containers
Proceed as follows:
Check the expiration date.
Read the advice for use on the label before
pouring the content of the bottle into the DEF
tank.
After the indication appears on the instru -
ment panel display Ú page 90 fill the DEF
tank with no more than 6 Gallons (22 liters).
CAUTION!
To avoid DEF spillage, and possible
damage to the DEF tank from overfilling, do
not “top off” the DEF tank after filling.
DO NOT OVERFILL. DEF will freeze below
12ºF (-11ºC). The DEF system is designed
to work in temperatures below the DEF
freezing point, however, if the tank is over -
filled and freezes, the system could be
damaged.
When DEF is spilled, clean the area imme -
diately with water and use an absorbent
material to soak up the spills on the ground.
Do not attempt to start your engine if DEF is
accidentally added to the diesel fuel tank
as it can result in severe damage to your
engine, including but not limited to failure
of the fuel pump and injectors.

21_DPF_OM_EN_USC_t.book Page 198

SAFETY275
Electronic Brake Force Distribution (EBD)
EBD manages the distribution of the braking
torque between the front and rear axles by
limiting braking pressure to the rear axle. This is
done to prevent overslip of the rear wheels to
avoid vehicle instability, and to prevent the rear
axle from entering ABS before the front axle.
Electronic Roll Mitigation (ERM)
ERM anticipates the potential for wheel lift by
monitoring the driver’s steering wheel input and
the speed of the vehicle. When ERM determines
that the rate of change of the steering wheel
angle and vehicle’s speed are sufficient to
potentially cause wheel lift, it then applies the
appropriate brake and may also reduce engine
power to lessen the chance that wheel lift will
occur. ERM can only reduce the chance of
wheel lift occurring during severe or evasive
driving maneuvers; it cannot prevent wheel lift
due to other factors, such as road conditions,
leaving the roadway, or striking objects or other
vehicles.
NOTE:
ERM is disabled any time the ESC is in “Full Off”
mode (if equipped). For a complete explanation
of the available ESC modes, see Ú page 275.
Electronic Stability Control (ESC)
ESC enhances directional control and stability
of the vehicle under various driving conditions.
ESC corrects for oversteering or understeering
of the vehicle by applying the brake of the
appropriate wheel(s) to counteract the above
conditions. Engine power may also be reduced
to help the vehicle maintain the desired path.

Oversteer — when the vehicle is turning more
than appropriate for the steering wheel position.
Understeer — when the vehicle is turning less
than appropriate for the steering wheel position.
ESC uses sensors in the vehicle to determine
the vehicle path intended by the driver and
compares it to the actual path of the vehicle.
When the actual path does not match the
intended path, ESC applies the brake of the
appropriate wheel to assist in counteracting the
oversteer or understeer condition.

The ESC Activation/Malfunction Indicator Light
located in the instrument cluster will start to flash
as soon as the ESC system becomes active.
The ESC Activation/Malfunction Indicator Light
also flashes when the TCS is active. If the ESC
Activation/Malfunction Indicator Light begins to
flash during acceleration, ease up on the
accelerator and apply as little throttle as possible.
Be sure to adapt your speed and driving to the
prevailing road conditions.

WARNING!

Many factors, such as vehicle loading, road
conditions and driving conditions, influence
the chance that wheel lift or rollover may occur.
ERM cannot prevent all wheel lift or roll overs,
especially those that involve leaving the
roadway or striking objects or other vehicles.
The capabilities of an ERM-equipped vehicle
must never be exploited in a reckless or
dangerous manner which could jeopardize
the user's safety or the safety of others.

6

21_DPF_OM_EN_USC_t.book Page 275

SAFETY281
Traction Control System (TCS)
TCS monitors the amount of wheel spin of each
of the driven wheels. If wheel spin is detected,
the TCS may apply brake pressure to the
spinning wheel(s) and/or reduce engine power
to provide enhanced acceleration and stability.
A feature of the TCS, Brake Limited Differential
(BLD), functions similarly to a limited slip
differential and controls the wheel spin across a
driven axle. If one wheel on a driven axle is
spinning faster than the other, the system will
apply the brake of the spinning wheel. This will
allow more engine power to be applied to the
wheel that is not spinning. BLD may remain
enabled even if TCS and Electronic Stability
Control (ESC) are in reduced modes.
Trailer Sway Control (TSC)
TSC uses sensors in the vehicle to recognize an
excessively swaying trailer and will take the
appropriate actions to attempt to stop the sway.
NOTE:
TSC cannot stop all trailers from swaying.
Always use caution when towing a trailer and
follow the trailer tongue weight recommenda -
tions Ú page 200.
When TSC is functioning, the ESC Activation/
Malfunction Indicator Light will flash, the engine
power may be reduced and you may feel the
brakes being applied to individual wheels to
attempt to stop the trailer from swaying. TSC is
disabled when the ESC system is in the “Partial
Off” or “Full Off” modes.
AUXILIARY DRIVING SYSTEMS
FORWARD COLLISION WARNING (FCW)
W
ITH MITIGATION — IF EQUIPPED
FCW with Mitigation provides the driver with
audible warnings, visual warnings (within the
instrument cluster display), and may apply a
brake jerk to warn the driver when it detects a
potential frontal collision. The warnings and
limited braking are intended to provide the
driver with enough time to react, avoid or
mitigate the potential collision.
NOTE:
FCW monitors the information from the forward
looking sensors as well as the Electronic Brake
Controller (EBC), to calculate the probability of a
forward collision. When the system determines
that a forward collision is probable, the driver
will be provided with audible and visual warn-
ings as well as a possible brake jerk warning.
If the driver does not take action based upon
these progressive warnings, then the system
will provide a limited level of active braking to
help slow the vehicle and mitigate the potential
forward collision. If the driver reacts to the warn -
ings by braking and the system determines that
HSA is not a parking brake. Always apply
the parking brake fully when exiting your
vehicle. Also, be certain to place the trans -
mission in PARK.
Failure to follow these warnings can result
in a collision or serious personal injury.
WARNING! (Continued)
WARNING!
If TSC activates while driving, slow the vehicle
down, stop at the nearest safe location, and
adjust the trailer load to eliminate trailer
sway.
6

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