2021 RAM 1500 warning light

318SAFETY
Ready Alert Braking (RAB)
RAB may reduce the time required to reach full
braking during emergency braking situations. It
anticipates when an emergency braking
situation may occur by monitoring how fast the
throttle is released by the driver. The Electronic
Brake Control System will prepare the brake
system for a panic stop.
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 torque 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 214.
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
BLIND SPOT MONITORING (BSM) — IF
E
QUIPPED
BSM uses two radar sensors, located inside the
taillights, to detect highway licensable vehicles
(automobiles, trucks, motorcycles, etc.) that
enter the blind spot zones from the rear/front/
side of the vehicle.

Rear Detection Zones

When the vehicle is started, the BSM Warning
Light will momentarily illuminate in both outside
rearview mirrors to let the driver know that the
system is operational. The BSM system sensors
operate when the vehicle is in any forward gear
or REVERSE and enters standby mode when the
vehicle is in PARK.
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.

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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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320SAFETY
Entering From The Side
Vehicles that move into your adjacent lanes
from either side of the vehicle.

Side Monitoring

Entering From The Rear
Vehicles that come up from behind your vehicle
on either side and enter the rear detection zone
with a relative speed of less than 30 mph
(48 km/h).
Rear Monitoring

Overtaking Traffic
If you pass another vehicle slowly with a relative
speed less than 15 mph (24 km/h) and the
vehicle remains in the blind spot for
approximately 1.5 seconds, the warning light
will be illuminated. If the difference in speed
between the two vehicles is greater than
15 mph (24 km/h), the warning light will not
illuminate.
Overtaking/Approaching
Overtaking/Passing

The BSM system is designed not to issue an
alert on stationary objects such as guardrails,
posts, walls, foliage, berms, snow banks, car
washes etc. However, occasionally the system
may alert on such objects. This is normal
operation and your vehicle does not require
service.

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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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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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SAFETY327
Pedestrian Emergency Braking (PEB) — If
Equipped
PEB is a subsystem of the FCW system that
provides the driver with audible and visual
warnings in the instrument cluster display, and
may apply automatic braking when it detects a
potential frontal collision with a pedestrian.
If a PEB event begins at a speed below 37 mph
(60 km/h), the system may provide braking to
mitigate the potential collision with a
pedestrian. If the PEB event stops the vehicle
completely, the system will hold the vehicle at a
standstill for two seconds and then release the
brakes. When the system determines a collision
with the pedestrian in front of you is no longer
probable, the warning message will be
deactivated.
The minimum speed for PEB activation is 3 mph
(5 km/h). Turning PEB On Or Off
NOTE:
The default status of PEB is “On.” This allows
the system to warn you of a possible frontal
collision with the pedestrian.
The PEB button is located in the Uconnect
display in the controls settings Ú
page 237.
To turn the PEB system off, push the Pedestrian
Emergency Braking button once.
To turn the PEB system back on, push the
Pedestrian Emergency Braking button again.
Changing the PEB status to “Off” deactivates
the system, so no warning or active braking will
be available in case of a possible frontal
collision with the pedestrian. NOTE:
The PEB system will NOT retain the last setting
selected by the driver after ignition shut down.
The system will reset to the default setting when
the vehicle is restarted.
TIRE PRESSURE MONITORING SYSTEM
(TPMS)
TPMS will warn the driver of a low tire pressure
based on the vehicle recommended cold
placard pressure.
NOTE:
The 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 pres -
sure values of each tire with the low tire pres -
sure values in a different color, or the Uconnect
radio will display a TPMS message; when this
occurs you must increase the tire pressure to
the recommended cold placard pressure in
order for the TPMS Warning Light to turn off.
The tire pressure will vary with temperature by
about 1 psi (7 kPa) for every 12°F (6.5°C). This
means that when the outside temperature
decreases, the tire pressure will decrease. Tire
WARNING!
Pedestrian Emergency Braking (PEB) is not
intended to avoid a collision on its own, nor
can PEB detect every type of potential colli -
sion with a pedestrian. The driver has the
responsibility to avoid a collision by con -
trolling the vehicle via braking and steering.
Failure to follow this warning could lead to
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

6

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