2021 RAM 1500 wheel

312SAFETY
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 the Anti-Lock Brake System
(ABS) before the front axle.
Electronic Roll Mitigation (ERM)
The ERM system 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, striking objects
or other vehicles.
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 posi -
tion.
Understeer — when the vehicle is turning less
than appropriate for the steering wheel posi -
tion.
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.

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SAFETY313
(Continued)
ESC Operating Modes
Depending upon model and mode of operation,
the ESC system may have multiple operating
modes. ESC On
This is the normal operating mode for the ESC.
Whenever the vehicle is started, the ESC system
will be in this mode. This mode should be used
for most driving conditions. Alternate ESC
modes should only be used for specific reasons
as noted in the following paragraphs.
Partial Off
This mode may be useful if the vehicle becomes
stuck. This mode may modify TCS and ESC
thresholds for activation, which allows for more
wheel spin than normally allowed.
To enter the “Partial Off” mode, momentarily
push the ESC OFF switch and the ESC OFF
Indicator Light will illuminate. To turn the ESC
on again, momentarily push the ESC OFF switch
and the ESC OFF Indicator Light will turn off.
NOTE:
For vehicles with multiple partial ESC modes,
the push and release of the button will toggle
the ESC modes. Multiple attempts may be
required to return to “ESC On”.
WARNING!
Electronic Stability Control (ESC) cannot
prevent the natural laws of physics from
acting on the vehicle, nor can it increase
the traction afforded by prevailing road
conditions. ESC cannot prevent accidents,
including those resulting from excessive
speed in turns, driving on very slippery
surfaces, or hydroplaning. ESC also cannot
prevent accidents resulting from loss of
vehicle control due to inappropriate driver
input for the conditions. Only a safe, atten
-
tive, and skillful driver can prevent acci -
dents. The capabilities of an ESC equipped
vehicle must never be exploited in a reck -
less or dangerous manner which could
jeopardize the user’s safety or the safety of
others.Vehicle modifications, or failure to properly
maintain your vehicle, may change the
handling characteristics of your vehicle,
and may negatively affect the performance
of the ESC system. Changes to the steering
system, suspension, braking system, tire
type and size or wheel size may adversely
affect ESC performance. Improperly
inflated and unevenly worn tires may also
degrade ESC performance. Any vehicle
modification or poor vehicle maintenance
that reduces the effectiveness of the ESC
system can increase the risk of loss of
vehicle control, vehicle rollover, personal
injury and death.
WARNING! (Continued)
6

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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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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
6

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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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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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342SAFETY
SUPPLEMENTAL RESTRAINT SYSTEMS
(SRS)
Some of the safety features described in this
section may be standard equipment on some
models, or may be optional equipment on
others. If you are not sure, ask an authorized
dealer.
The air bag system must be ready to protect you
in a collision. The Occupant Restraint Controller
(ORC) monitors the internal circuits and
interconnecting wiring associated with the
electrical Air Bag System Components. Your
vehicle may be equipped with the following Air
Bag System Components:
Air Bag System Components
Occupant Restraint Controller (ORC)
Air Bag Warning Light
Steering Wheel and Column
Instrument Panel
Knee Impact Bolsters
Driver and Front Passenger Air Bags
Seat Belt Buckle Switch
Supplemental Side Air Bags
Front and Side Impact Sensors
Seat Belt Pretensioners
Seat Track Position Sensors
Occupant Classification System
Air Bag Warning Light
The Occupant Restraint Controller
(ORC) monitors the readiness of the
electronic parts of the air bag system
whenever the ignition switch is in the
START or ON/RUN position. If the ignition switch
is in the OFF position or in the ACC position, the
air bag system is not on and the air bags will not
inflate. The ORC contains a backup power supply
system that may deploy the air bag system even
if the battery loses power or it becomes
disconnected prior to deployment.
The ORC turns on the Air Bag Warning Light in
the instrument panel for approximately four to
eight seconds for a self-check when the ignition
switch is first in the ON/RUN position. After the
self-check, the Air Bag Warning Light will turn
off. If the ORC detects a malfunction in any part
of the system, it turns on the Air Bag Warning
Light, either momentarily or continuously. A
single chime will sound to alert you if the light
comes on again after initial startup.
The ORC also includes diagnostics that will
illuminate the instrument panel Air Bag Warning
Light if a malfunction is detected that could
affect the air bag system. The diagnostics also
record the nature of the malfunction. While the
air bag system is designed to be maintenance
free, if any of the following occurs, have an
authorized dealer service the air bag system
immediately.
Failure to replace the seat belt assembly
could increase the risk of injury in colli
-
sions.
Do not use the Automatic Locking Mode to
restrain occupants who are wearing the
seat belt or children who are using booster
seats. The locked mode is only used to
install rear-facing or forward-facing child
restraints that have a harness for
restraining the child.
WARNING! (Continued)

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