2021 RAM PROMASTER CITY sensor

146SAFETY
Electronic Brake Control (EBC) System
Your vehicle is equipped with an advanced
Electronic Brake Control (EBC) system that
includes the Brake Assist System (BAS),
Traction Control System (TCS), Hill Start Assist
(HSA), Electronic Stability Control (ESC),
Electronic Roll Mitigation (ERM) and Trailer
Sway Control (TSC). All systems work together to
enhance vehicle stability and control in various
driving conditions and are commonly referred to
as ESC.
Brake Assist System (BAS)
BAS is designed to optimize the vehicle’s
braking capability during emergency braking
maneuvers. The system detects an emergency
braking situation by sensing the rate and
amount of brake application and then applies
optimum pressure to the brakes. This can help
reduce braking distances. The BAS
complements the Anti-Lock Brake System
(ABS). Applying the brakes very quickly results
in the best BAS assistance. To receive the
benefit of the system, you must apply continuous braking pressure during the
stopping sequence (do not “pump” the brakes).
Do not reduce brake pedal pressure unless
braking is no longer desired. Once the brake
pedal is released, the BAS is deactivated.
Electronic Stability Control (ESC)
ESC enhances directional control and stability
of the vehicle under various driving conditions.
ESC corrects for over/under steering of the
vehicle by applying the brake of the appropriate
wheel 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.
WARNING!
The Brake Assist System (BAS) cannot
prevent the natural laws of physics from
acting on the vehicle, nor can it increase the
traction afforded by prevailing road
conditions. BAS cannot prevent collisions,
including those resulting from excessive
speed in turns, driving on very slippery
surfaces, or hydroplaning. The capabilities of
a BAS-equipped vehicle must never be
exploited in a reckless or dangerous manner,
which could jeopardize the user's safety or
the safety of others.

21_VM_OM_EN_USC_t.book Page 146

SAFETY149
HSA will work in REVERSE and all forward gears
when the activation criteria have been met. The
system will not activate if the vehicle is placed
in NEUTRAL or PARK.
Traction Control System (TCS)
TCS monitors the amount of wheel spin of each
of the driven wheels. If wheel spin is detected,
brake pressure is applied to the slipping
wheel(s) and engine power is reduced to
provide enhanced acceleration and stability. A
feature of the TCS system, 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. This
feature remains active even if TCS and ESC are
in the “Partial Off” mode Ú
page 146.
Trailer Sway Control (TSC) — If Equipped
TSC uses sensors in the vehicle to recognize an
excessively swaying trailer and will take the
appropriate actions to attempt to stop the sway.
The system may reduce engine power and apply
the brake of the appropriate wheel(s) to
counteract the sway of the trailer.
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 77.
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” mode.
AUXILIARY DRIVING SYSTEMS
Tire Pressure Monitoring System (TPMS)
The Tire Pressure Monitoring System (TPMS)
will warn the driver of a low tire pressure based
on the vehicle recommended cold placard
pressure.
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
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
WARNING!
There may be situations on minor hills with a
loaded vehicle, or while pulling a trailer, when
the system will not activate and slight rolling
may occur. This could cause a collision with
another vehicle or object. Always remember
the driver is responsible for braking the
vehicle.
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

21_VM_OM_EN_USC_t.book Page 149

150SAFETY
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 234 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.
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 tire pressure warning
(TPMS Warning Light) illuminates, you must
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.

21_VM_OM_EN_USC_t.book Page 150

SAFETY151
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.
Driving on a significantly under-inflated tire
causes the tire to overheat and can lead to
tire failure. Under-inflation 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
under-inflation 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 Ú page 265.
Base System
This is the TPMS warning indicator
located in the instrument cluster.
The 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
regularly and to maintain the proper pressure.
The TPMS consists of the following
components:
Receiver Module
Four Tire Pressure Monitoring sensors
Tire Pressure Monitoring System Warning
Light
Tire Pressure Monitoring Low Pressure
Warnings
The Tire Pressure Monitoring System Warning
Light will illuminate in the instrument cluster, an
audible chime will be activated, and the “Check
tire pressure” text message will display when
one or more of the four active road tire
pressures are low. Should this occur, you
should stop as soon as possible, check the
inflation pressure of each tire on your vehicle,
and inflate each tire to the vehicle’s
recommended cold placard pressure value. The
system will automatically update and the Tire
Pressure Monitoring Light will extinguish once
the updated tire pressures have been received.
The vehicle may need to be driven for up to
20 minutes above 15 mph (24 km/h) to receive
this information.
6

21_VM_OM_EN_USC_t.book Page 151

152SAFETY
Check TPMS Warnings
The Tire Pressure Monitoring Warning Light will
flash on and off for 75 seconds and remain on
solid when a system fault is detected, an
audible chime will be activated and a proper
text message will be displayed. If the ignition
key is cycled, this sequence will repeat
providing the system fault still exists. The Tire
Pressure Monitoring Warning Light will turn off
when the fault condition no longer exists. A
system fault can occur with any of the following
scenarios:

1. Jamming due to electronic devices or
driving next to facilities emitting the same
radio frequencies as the TPM sensors.

2. Installing some form of aftermarket window tinting that affects radio wave signals.
3. Snow or ice around the wheels or wheel housings. 4. Using tire chains on the vehicle.
5. Using wheels/tires not equipped with TPM
sensors.
NOTE:
Your vehicle can be equipped with either a Tire
Service Kit, a compact spare tire or a regular
size spare tire (with or without original TPMS
sensor).

1. Tire Service Kit (original tire sealant – if equipped): After fixing the punctured tire
with original tire sealant, the original
situation will be restored, so system will
turn off the telltale during the normal drive.

2. Compact Spare Tire – if equipped: The compact spare wheel is not equipped with a
TPMS sensor. So when mounted, during the
normal drive the system will turn on the
telltale (flashing for approximately
75 seconds then remains solid). This
condition persists until a wheel equipped
with original TPMS sensor has been
mounted on the vehicle. 3. Regular size spare tire (not equipped with
TPMS sensor): When mounted, during the
normal drive the system will turn on the
telltale (flashing for approximately
75 seconds then remains solid). This
condition persists until a wheel equipped
with original TPMS sensor has been
mounted on the vehicle. Then the system
will be restored and the telltale will turn off
during the normal drive.
4. Regular size spare tire (equipped with TPMS sensor): When mounted, the telltale will
turn off during the normal drive.
5. In all the above cases, please check the replacement tire inflation pressure before
driving your vehicle.
6. In case of tire replacement, if the vehicle is driven for short periods of time, then the
system can take a while to be restored.
NOTE:
For a correct Tire Pressure Monitoring behavior,
please wait for about 20 minutes in key-off
during each tire substitution.

21_VM_OM_EN_USC_t.book Page 152

SAFETY161
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
Supplemental Knee Air Bags
Front and Side Impact Sensors
Seat Belt Pretensioners
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
AVV/START or MAR/ACC/ON/RUN position. If
the ignition switch is in the STOP/OFF/LOCK
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 in the MAR/ACC/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)
6

21_VM_OM_EN_USC_t.book Page 161

SAFETY163
Driver and Passenger Front Air Bag Features
The Advanced Front Air Bag system has
multistage driver and front passenger air bags.
This system provides output appropriate to the
severity and type of collision as determined by
the Occupant Restraint Controller (ORC), which
may receive information from the front impact
sensors (if equipped) or other system
components.
The first stage inflator is triggered immediately
during an impact that requires air bag
deployment. A low energy output is used in less
severe collisions. A higher energy output is used
for more severe collisions.
This vehicle may be equipped with a driver and/
or front passenger seat belt buckle switch that
detects whether the driver or front passenger
seat belt is buckled. The seat belt buckle switch
may adjust the inflation rate of the Advanced
Front Air Bags.
Front Air Bag Operation
Front Air Bags are designed to provide
additional protection by supplementing the seat
belts. Front air bags are not expected to reduce
the risk of injury in rear, side, or rollover
collisions. The front air bags will not deploy in all
frontal collisions, including some that may
produce substantial vehicle damage — for
example, some pole collisions, truck
underrides, and angle offset collisions.
On the other hand, depending on the type and
location of impact, front air bags may deploy in
crashes with little vehicle front-end damage but
that produce a severe initial deceleration.
Because air bag sensors measure vehicle
deceleration over time, vehicle speed and
damage by themselves are not good indicators
of whether or not an air bag should have
deployed.
Seat belts are necessary for your protection in
all collisions, and also are needed to help keep
you in position, away from an inflating air bag.
When the Occupant Restraint Controller (ORC)
detects a collision requiring the front air bags, it
signals the inflator units. A large quantity of
non-toxic gas is generated to inflate the front air
bags.WARNING!
No objects should be placed over or near
the air bag on the instrument panel or
steering wheel because any such objects
could cause harm if the vehicle is in a colli -
sion severe enough to cause the air bag to
inflate.
Do not put anything on or around the air
bag covers or attempt to open them manu -
ally. You may damage the air bags and you
could be injured because the air bags may
no longer be functional. The protective
covers for the air bag cushions are
designed to open only when the air bags
are inflating.
Relying on the air bags alone could lead to
more severe injuries in a collision. The air
bags work with your seat belt to restrain you
properly. In some collisions, air bags won’t
deploy at all. Always wear your seat belts
even though you have air bags.
6

21_VM_OM_EN_USC_t.book Page 163

SAFETY165
Supplemental Side Air Bag Inflatable Curtains
(SABICs)
This vehicle is equipped with Supplemental
Side Air Bag Inflatable Curtains (SABICs).
Supplemental Side Air Bag Inflatable Curtains
(SABICs) are located above the side windows.
The trim covering the SABICs is labeled “SRS
AIRBAG” or “AIRBAG.”

Supplemental Side Air Bag Inflatable Curtain (SABIC) Label Location

SABICs may help reduce the risk of head and
other injuries to front and rear seat outboard
occupants in certain side impacts, in addition to
the injury reduction potential provided by the
seat belts and body structure.
The SABIC deploys downward, covering the side
windows. An inflating SABIC pushes the outside edge of the headliner out of the way and covers
the window. The SABICs inflate with enough
force to injure occupants if they are not belted
and seated properly, or if items are positioned
in the area where the SABICs inflate. Children
are at an even greater risk of injury from a
deploying air bag.
The SABICs may help reduce the risk of partial
or complete ejection of vehicle occupants
through side windows in certain side impact
events.
Side Impacts
The Side Air Bags are designed to activate in
certain side impacts. The Occupant Restraint
Controller (ORC) determines whether the
deployment of the Side Air Bags in a particular
impact event is appropriate, based on the
severity and type of collision. The side impact
sensors aid the ORC in determining the
appropriate response to impact events. The
system is calibrated to deploy the Side Air Bags
on the impact side of the vehicle during impacts
that require Side Air Bag occupant protection. In
side impacts, the Side Air Bags deploy
independently; a left side impact deploys the
left Side Air Bags only and a right-side impact
deploys the right Side Air Bags only. Vehicle
damage by itself is not a good indicator of
whether or not Side Air Bags should have
deployed.
The Side Air Bags will not deploy in all side
collisions, including some collisions at certain
angles, or some side collisions that do not
impact the area of the passenger compartment.
The Side Air Bags may deploy during angled or
offset frontal collisions where the front air bags
deploy.
WARNING!
Do not mount equipment, or stack luggage
or other cargo up high enough to block the
deployment of the SABICs. The trim
covering above the side windows where the
SABIC and its deployment path are located
should remain free from any obstructions.
In order for the SABICs to work as intended,
do not install any accessory items in your
vehicle which could alter the roof. Do not
add an aftermarket sunroof to your vehicle.
Do not add roof racks that require perma
-
nent attachments (bolts or screws) for
installation on the vehicle roof. Do not drill
into the roof of the vehicle for any reason.
6

21_VM_OM_EN_USC_t.book Page 165