2021 RAM 1500 sensor

SAFETY319
The BSM detection zone covers approximately
one lane width on both sides of the vehicle 12 ft
(3.8 m). The zone length starts at the outside
rear view mirror and extends approximately
10 ft (3 m) beyond the rear fascia/bumper of
the vehicle. The BSM system monitors the
detection zones on both sides of the vehicle
when the vehicle speed reaches approximately
6 mph (10 km/h) or higher and will alert the
driver of vehicles in these areas.
NOTE:
The BSM system DOES NOT alert the driver
about rapidly approaching vehicles that are
outside the detection zones.
BSM may experience dropouts (blinking on
and off) of the side mirror warning indicator
lamps when a motorcycle or any small object
remains at the side of the vehicle for
extended periods of time (more than a couple
of seconds).
The vehicle’s taillights, where the radar sensors
are located, must remain free of snow, ice, and
dirt/road contamination so that the BSM
system can function properly. Do not block the
taillights with foreign objects (bumper stickers,
bicycle racks, etc.).
Radar Sensor Locations

If the system detects degraded performance
due to contamination or foreign objects, a
message will warn you of a blocked sensor and
the warning indicators in side view mirrors will
be on. The warning indicators will remain
illuminated until blockage clearing conditions
are met. First clear the taillights around the
sensors of the blockage. After removing the
blockage, the following procedure can be used
to reset the system:
Cycle the ignition from ON to OFF and then back
ON.
If the blockage message is still present after
cycling the ignition and driving in traffic, check
again for a blockage. The system may also detect a blockage if the
vehicle is operated in areas with extremely low
radar returns such as a desert or parallel to a
large elevation drop.
The BSM system notifies the driver of objects in
the detection zones by illuminating the BSM
warning light located in the outside mirrors, in
addition to sounding an audible (chime) alert
and reducing the radio volume Ú
page 322.

Warning Light Location

The BSM system monitors the detection zone
from three different entry points (side, rear,
front) while driving to see if an alert is
necessary. The BSM system will issue an alert
during these types of zone entries.
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SAFETY321
The BSM system will not alert you of objects that
are traveling in the opposite direction of the
vehicle in adjacent lanes Ú page 482.

Opposing Traffic

For information on how Blind Spot Monitoring
functions when pulling a trailer Ú page 322.Rear Cross Path (RCP)
RCP is intended to aid the driver when backing
out of parking spaces where their vision of
oncoming vehicles may be blocked. Proceed
slowly and cautiously out of the parking space
until the rear end of the vehicle is exposed. The
RCP system will then have a clear view of the
cross traffic, and if an oncoming vehicle is
detected, alert the driver.

RCP Detection Zones

RCP monitors the rear detection zones on both
sides of the vehicle, for objects that are moving
toward the side of the vehicle with a minimum
speed of approximately 3 mph (5 km/h), to
objects moving a maximum of approximately
20 mph (32 km/h), such as in parking lot
situations. When RCP is on and the vehicle is in REVERSE
(R), the driver is alerted using both the visual
and audible alarms, including reducing the
radio volume.
NOTE:
In a parking lot situation, oncoming vehicles can
be blocked by vehicles parked on either side. If
the sensors are blocked by other structures or
vehicles, the system will not be able to alert the
driver.
WARNING!
The Blind Spot Monitoring system is only an
aid to help detect objects in the blind spot
zones. The BSM system is not designed to
detect pedestrians, bicyclists, or animals.
Even if your vehicle is equipped with the BSM
system, always check your vehicle’s mirrors,
glance over your shoulder, and use your turn
signal before changing lanes. Failure to do so
can result in serious injury or death.
WARNING!
Rear Cross Path Detection (RCP) is not a
backup aid system. It is intended to be used
to help a driver detect an oncoming vehicle in
a parking lot situation. Drivers must be
careful when backing up, even when using
RCP. 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. Failure to do so can result in
serious injury or death.6

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322SAFETY
Blind Spot Modes
Blind Spot has three selectable modes of
operation that are available in the Uconnect
system.
Blind Spot Alert Lights Only
When operating in Blind Spot Alert mode, the
BSM system will provide a visual alert in the
appropriate side view mirror based on a
detected object. However, when the system is
operating in Rear Cross Path (RCP) mode, the
system will respond with both visual and
audible alerts when a detected object is
present. Whenever an audible alert is
requested, the radio is muted.
Blind Spot Alert Lights/Chime
When operating in Blind Spot Alert Lights/
Chime mode, the BSM system will provide a
visual alert in the appropriate side view mirror
based on a detected object. If the turn signal is
then activated, and it corresponds to an alert
present on that side of the vehicle, an audible
chime will also be sounded. Whenever a turn
signal and detected object are present on the
same side at the same time, both the visual and
audible alerts will be issued. In addition to the
audible alert the radio (if on) will also be muted. NOTE:
Whenever an audible alert is requested by the
BSM system, the radio is also muted.
When the system is in RCP, the system shall
respond with both visual and audible alerts
when a detected object is present. Whenever
an audible alert is requested, the radio is also
muted. Turn/hazard signal status is ignored;
the RCP state always requests the chime.
Blind Spot Alert Off
When the BSM system is turned off there will be
no visual or audible alerts from either the BSM,
RCP, or Trailer Merge Assist systems.
NOTE:
The BSM system will store the current operating
mode when the vehicle is shut off. Each time
the vehicle is started the previously stored
mode will be recalled and used.
Trailer Merge Assist – If Equipped
Trailer Merge Assist is a function of the Blind
Spot Monitoring (BSM) system that extends the
blind spot zone to work while pulling a trailer.
NOTE:
When Trailer Merge Assist is activated, Rear
Cross Path is disabled.Trailer Merge Assist consists of three sub
functions:
Automatic Trailer Detection
Trailer Length Detection
Trailer Merge Warning

Blind Spot Zones With Trailer Merge Assist

Automatic Trailer Detection
There are two modes of operation for the
detection of the trailer length:
Automatic Mode — When “Auto Mode” is
selected, the system will use the blind spot
sensors to automatically determine the pres -
ence and length of a trailer. The presence of
1 — Vehicle
2 — Trailer

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SAFETY323
a trailer will be detected using the blind spot
radar within 90 seconds of forward move -
ment of the vehicle. The vehicle must be
moving above 6 mph (10 km/h) to activate the feature. Once the trailer has been
detected, the system will default to the
maximum blind spot zone until the length has
been verified. You will see “Auto” in the
instrument panel cluster .
Maximum Mode — When “Max Mode” is
selected, the system will default to the
maximum blind spot zone regardless of what
size trailer is attached .
NOTE:
Selected setting is stored when the ignition is
placed in the OFF position. To change this
setting, it must be selected through the
Uconnect settings Ú page 237.
Trailer Length Detection
Once the trailer presence has been established,
the trailer length will be established (by making
a 90 degree turn) and then the trailer length
category (example 10-20 ft (3 m to 6 m)) will be
displayed. This can take up to 30 seconds after
completing the turn. NOTE:
During the same ignition cycle, if the vehicle is
at a standstill for a minimum of 90 seconds, a
new “trailer detection request” is enabled by
the system once the vehicle resumes motion.
Maximum length supported by the Trailer Merge
Assist feature is 39.5 ft (12 m). Trailer length is
considered the forward most portion of the
trailer hitch to the rearward most portion of the
body, fascia/bumper, or ramp of the trailer.
Maximum width supported by the Trailer Merge
Assist feature is 8.5 ft (2.59 m). Trailer width is
measured at the widest portion of the trailer
and may include wheels, tires, finders, or rails.
NOTE:
Fifth wheel or gooseneck trailers are not
supported by Trailer Merge Assist.
NOTE:
The ability to detect a trailer may be degraded in
crowded or busy environments. Busy parking
lots, narrow areas surrounded with trees, or any
other crowded area may prevent the radar
sensors from being able to adequately detect
the trailer. The system will try to detect a trailer
at every ignition cycle or 90 seconds of stand
-
still.
Trailer Length Detection

Trailer length will be identified and placed into
one of the following categories:
Trailer length up to 10 ft (3 m) — Blind spot
zone will be adjusted to 10 ft (3 m) .
Trailer length between 10 ft to 20 ft (3 m to
6 m) — Blind spot zone will be adjusted to
20 ft (6 m) .
Trailer length between 20 ft to 30 ft (6 m to
9 m) — Blind spot zone will be adjusted to
30 ft (9 m) .
1 — Trailer Length
2 — Trailer Width
3 — Trailer Hitch
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324SAFETY
Trailer length between 30 ft and 39.5 ft (9 m
to 12 m) — Blind spot zone will be adjusted to
Max distance .
NOTE:
Trailer length is determined within +/- 3 ft (1 m)
of actual length. Trailers that are the same size
as the category limit, 10/20/30 ft (3/6/9 m),
could be subject to being placed in the category
above or below the correct one.
Trailer Merge Warning
Trailer Merge Warning is the extension of the
blind spot function to cover the length of the
trailer, plus a safety margin, to warn the driver
when there is a vehicle in the adjacent lane. The
driver is alerted by the illumination of the BSM
warning light located in the outside mirror on
the side the other vehicle is detected on. In
addition, an audible (chime) alert will be heard
and radio volume will be reduced Ú page 322.
NOTE:
The Trailer Merge Alert system DOES NOT
alert the driver about rapidly approaching
vehicles that are outside the detection zones.
The Blind Spot Monitoring (BSM) system may
experience drop outs (blinking on and off) of the side mirror warning indicator lamps when
a motorcycle or any small object remains at
the side of the vehicle for extended periods of
time (more than a couple of seconds).
Crowded areas such as parking lots, neigh
-
borhoods, etc. may lead to an increased
amount of false alerts. This is normal opera -
tion.
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
the driver intends to avoid the collision by
braking but has not applied sufficient brake
force, the system will compensate and provide
additional brake force as required.
If a FCW with Mitigation event begins at a speed
below 32 mph (52 km/h), the system may
provide the maximum braking possible to miti -
gate the potential forward collision. If the
WARNING!
The Blind Spot Monitoring system is only an
aid to help detect objects in the blind spot
zones. The BSM system is not designed to
detect pedestrians, bicyclists, or animals.
Even if your vehicle is equipped with the BSM
system, always check your vehicle’s mirrors,
glance over your shoulder, and use your turn
signal before changing lanes. Failure to do so
can result in serious injury or death.

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328SAFETY
pressure should always be set based on cold
inflation tire pressure. This is defined as the tire
pressure after the vehicle has not been driven
for at least three hours, or driven less than
1 mile (1.6 km) after a three hour period. The
cold tire inflation pressure must not exceed the
maximum inflation pressure molded into the
tire sidewall. The tire pressure will also increase
as the vehicle is driven — this is normal and
there should be no adjustment for this
increased pressure.
See Úpage 443 on how to properly inflate the
vehicle’s tires.
The TPMS will warn the driver of a low tire
pressure if the tire pressure falls below the
low-pressure warning limit for any reason,
including low temperature effects and natural
pressure loss through the tire Ú page 482.
The TPMS will continue to warn the driver of low
tire pressure as long as the condition exists,
and will not turn off until the tire pressure is at
or above the recommended cold placard
pressure. Once the low TPMS Warning Light
illuminates, increase the tire pressure to the
recommended cold placard pressure in order
for the TPMS Warning Light to turn off. The
system will automatically update and the TPMS Warning Light will turn off once the system
receives the updated tire pressures. The vehicle
may need to be driven for up to 20 minutes
above 15 mph (24 km/h) in order for the TPMS
to receive this information.
NOTE:
When filling warm tires, the tire pressure may
need to be increased up to an additional 4 psi
(28 kPa) above the recommended cold placard
pressure in order to turn the TPMS Warning
Light off.
For example, your vehicle may have a
recommended cold (parked for more than three
hours) placard pressure of 30 psi (207 kPa). If
the ambient temperature is 68°F (20°C) and
the measured tire pressure is 27 psi (186 kPa),
a temperature drop to 20°F (-7°C) will
decrease the tire pressure to approximately
23 psi (158 kPa). This tire pressure is
sufficiently low enough to turn on the TPMS
Warning Light. Driving the vehicle may cause
the tire pressure to rise to approximately 27 psi
(186 kPa), but the TPMS Warning Light will still
be on. In this situation, the TPMS Warning Light
will turn off only after the tires are inflated to the
vehicle’s recommended cold placard pressure
value.CAUTION!
The TPMS has been optimized for the orig -
inal equipment tires and wheels. TPMS
pressures and warning have been estab -
lished for the tire size equipped on your
vehicle. Undesirable system operation or
sensor damage may result when using
replacement equipment that is not of the
same size, type, and/or style. Aftermarket
wheels can cause sensor damage.
Using aftermarket tire sealants may cause
the Tire Pressure Monitoring System
(TPMS) sensor to become inoperable. After
using an aftermarket tire sealant it is
recommended that you take your vehicle to
an authorized dealership to have your
sensor function checked.
After inspecting or adjusting the tire pres -
sure always reinstall the valve stem cap.
This will prevent moisture and dirt from
entering the valve stem, which could
damage the TPMS sensor.

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SAFETY329
NOTE:
The TPMS is not intended to replace normal
tire care and maintenance or to provide
warning of a tire failure or condition.
The TPMS should not be used as a tire pres -
sure gauge while adjusting your tire pressure,
unless your vehicle is equipped with a Tire Fill
Alert (TFA) system.
Driving on a significantly underinflated tire
causes the tire to overheat and can lead to
tire failure. Underinflation also reduces fuel
efficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability.
The TPMS is not a substitute for proper tire
maintenance, and it is the driver’s responsi -
bility to maintain correct tire pressure using
an accurate tire pressure gauge, even if
underinflation has not reached the level to
trigger illumination of the TPMS Warning
Light.
Seasonal temperature changes will affect
tire pressure, and the TPMS will monitor the
actual tire pressure in the tire.
Tire Pressure Monitoring Display

The Tire Pressure Monitoring System (TPMS)
uses wireless technology with wheel rim
mounted electronic sensors to monitor tire
pressure levels. Sensors, mounted to each
wheel as part of the valve stem, transmit tire
pressure readings to the receiver module.
NOTE:
It is particularly important for you to check the
tire pressure in all of the tires on your vehicle
monthly and to maintain the proper pressure.
The TPMS consists of the following
components:
Receiver module
Four Tire Pressure Monitoring System
sensors
Various Tire Pressure Monitoring System
messages, which display in the instrument
cluster
Tire Pressure Monitoring System Warning
Light
Tire Pressure Monitoring Low Pressure
Warnings
The Tire Pressure Monitoring System
(TPMS) Warning Light will illuminate
in the instrument cluster and a chime
will sound when tire pressure is low in
one or more of the four active road tires. In
addition, the instrument cluster will display a
graphic showing the pressure values of each
tire with the low tire pressure values in a
different color. An "Inflate to XX" message will
also be displayed.

Low Tire Pressure Display

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330SAFETY
Should this occur, you should stop as soon as
possible and inflate the tires with a low pressure
condition (those in a different color in the
instrument cluster graphic) to the vehicle’s
recommended cold placard pressure inflation
value as shown in the "Inflate to XX" message.
Once the system receives the updated tire
pressures, the system will automatically
update, the graphic display in the instrument
cluster will return to its original color, and the
Tire Pressure Monitoring System Warning Light
will turn off. The vehicle may need to be driven
for up to 20 minutes above 15 mph (24 km/h)
in order for the TPMS to receive this
information.
NOTE:
When filling warm tires, the tire pressure may
need to be increased up to an additional 4 psi
(28 kPa) above the recommended cold placard
pressure in order to turn the Tire Pressure Moni -
toring System Warning Light off.
Service TPMS Warning
If a system fault is detected, the Tire Pressure
Monitoring System (TPMS) Warning Light will
flash on and off for 75 seconds and then remain
on solid. The system fault will also sound a
chime. In addition, the instrument cluster will display a "SERVICE TPMS SYSTEM" message for
a minimum of five seconds and then display
dashes (--) in place of the pressure value to
indicate which sensor is not being received.
If the ignition switch is cycled, this sequence will
repeat, providing the system fault still exists. If
the system fault no longer exists, the Tire
Pressure Monitoring System Warning Light will
no longer flash, and the "SERVICE TPMS
SYSTEM" message will no longer display, and a
pressure value will display in place of the
dashes. A system fault can occur due to any of
the following:
Signal interference due to electronic devices
or driving next to facilities emitting the same
radio frequencies as the Tire Pressure Moni
-
toring System sensors
Installing aftermarket window tinting that
contains materials that may block radio wave
signals
Accumulation of snow or ice around the
wheels or wheel housings
Using tire chains on the vehicle
Using wheels/tires not equipped with TPMS
sensors A system fault may occur due to an incorrect
TPMS sensor location condition. When a system
fault occurs due to an incorrect TPMS sensor
location, the Tire Pressure Monitoring System
(TPMS) Warning Light will flash on and off for
75 seconds and then remain on solid. The
system fault will also sound a chime. In
addition, the instrument cluster will display a
Tire Pressure Temporarily Unavailable message
in place of the tire pressure display screen. If
the ignition switch is cycled, this sequence will
repeat, providing the system fault still exists. If
the system fault no longer exists, the “Tire
Pressure Monitoring System Warning Light” will
no longer flash and the tire pressure display
screen will be displayed showing the tire
pressure values the correct locations.
Vehicles With Non-Matching Full Size Spare Or
Compact Spare
The non-matching full size spare or compact
spare tire does not have a TPMS sensor.
Therefore, the TPMS will not monitor the
pressure in the non-matching full size spare
or compact spare tire.
If you install the non-matching full size spare
or compact spare tire in place of a road tire
that has a pressure below the low-pressure

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